omeprazole/sodium bicarbonate (Rx, OTC)

Duodenal Ulcer

Zegerid only

Indicated for active duodenal ulcer

20 mg omeprazole PO qDay for 4-8 weeks

Gastric Ulcer

Zegerid and Konvomep

Indicated for short-term treatment of active benign gastric ulcer

40 mg omeprazole PO qDay for 4-8 weeks

Erosive Esophagitis

Zegerid only

Short-term treatment

• Indicated for short-term treatment of erosive esophagitis (EE) due to acid-mediated gastroesophageal reflux disease (GERD) which has been diagnosed by endoscopy
• 20 mg omeprazole PO qDay for 4-8 weeks
• Use for longer than 8 weeks in patients with EE has not been established
• If no response to 8 weeks of treatment, an additional 4 weeks of treatment may be given
• If EE or GERD symptoms recur, consider an additional 4-8 week course

Maintenance of healing

• 20 mg omeprazole PO qDay
• Controlled studies do not extend beyond 12 months

• Asian individuals and CYP2C19 poor metabolizers

  • Avoid omeprazole as maintenance therapy in CYP2C19 poor metabolizers or individuals of Asian descent
  • Asians have ~4-fold higher systemic exposure of omeprazole compared with Caucasians

Symptomatic GERD

Zegerid only

20 mg omeprazole PO qDay for up to 4 weeks

Upper GI Bleeding

Zegerid and Konvomep

Oral suspension

• Indicated for risk reduction of upper GI bleeding in critically ill patients
• 40 mg PO initially; followed by 40 mg 6-8 hr later
• Thereafter, 40 mg PO qDay up to 14 days

Heartburn (OTC Label)

20 mg PO qDay for 14 days; not to exceed 14 days or more often than every 4 months unless under the supervision of a healthcare professional

Dosage Modifications

Hepatic impairment

• Mild-to-severe (Child-Pugh Class A, B, or C): Exposure to omeprazole substantially increased compared to healthy subjects
• Avoid use in patients with hepatic impairment for maintenance of healing of erosive esophagitis

Safety and efficacy not established

Contraindicated (5)

• erlotinib

  omeprazole decreases levels of erlotinib by Other (see comment). Contraindicated. Comment: Concomitant use of proton pump inhibitors with erlotinib should be avoided if possible. Drugs that alter pH of upper GI tract may alter the solubility of erlotinib and reduce its bioavailability. .

• fezolinetant

  omeprazole will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors

• mavacamten

  omeprazole will increase the level or effect of mavacamten by affecting hepatic enzyme CYP2C19 metabolism. Contraindicated. Strong or moderate CYP2C19 inhibitors may increase mavacamten systemic exposure, resulting in heart failure due to systolic dysfunction.

• nelfinavir

  omeprazole decreases levels of nelfinavir by unspecified interaction mechanism. Contraindicated. Coadministration may lead to loss of nelfinavir virologic response and development of resistance; mechanism may be CYP2C19 inhibition of nelfinavir conversion to active M8 metabolite, and also PPIs decreasing gastric pH resulting in decreased nelfinavir absorption.

• rilpivirine

  omeprazole decreases levels of rilpivirine by increasing gastric pH. Applies only to oral form of both agents. Contraindicated. Concurrent use may cause treatment failure and/or the development of rilpivirine or NNRTI resistance owing to decreased levels.

Serious - Use Alternative (59)

• abrocitinib

  omeprazole will increase the level or effect of abrocitinib by decreasing metabolism. Avoid or Use Alternate Drug. Abrocitinib is a CYP2C9 and CYP2C19 substrate. Drugs that are moderate-to-strong inhibitors of both CYP2C9 and CYP2C19 increase systemic exposure of abrocitinib and its active metabolites, which may increase adverse effects.

• acalabrutinib

  omeprazole decreases levels of acalabrutinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Acalabrutinib solubility decreases with increasing gastric pH. Due to the long-lasting effect of PPIs, separation of doses may not eliminate the interaction.

• apalutamide

  apalutamide will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP2C19 inducer, with drugs that are CYP2C19 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered.
  
  apalutamide will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

• atazanavir

  sodium bicarbonate will decrease the level or effect of atazanavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  omeprazole will decrease the level or effect of atazanavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Atazanavir solubility decreases as pH increases. Substantially reduced plasma concentrations of atazanavir are expected if PPIs are coadministered. PPI dose should not exceed a dose comparable to omeprazole 20 mg and must be taken ~12 h before atazanavir/ritonavir in treatment naive-patients. PPIs are not recommended in treatment-experienced taking atazanavir.

• carbamazepine

  carbamazepine will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.

• dapsone

  sodium bicarbonate will decrease the level or effect of dapsone by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• ceritinib

  omeprazole decreases effects of ceritinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• cilostazol

  omeprazole will increase the level or effect of cilostazol by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.

• clopidogrel

  omeprazole decreases effects of clopidogrel by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug. Clopidogrel efficacy may be reduced by drugs that inhibit CYP2C19. Inhibition of platelet aggregation by clopidogrel is entirely due to an active metabolite. Clopidogrel is metabolized to this active metabolite in part by CYP2C19. .

• dacomitinib

  omeprazole will increase the level or effect of dacomitinib by unspecified interaction mechanism. Avoid or Use Alternate Drug. Concomitant use with a PPI decreases dacomitinib concentrations, which may reduce dacomitinib efficacy. Avoid use of PPIs with dacomitinib. As an alternative to PPIs, use locally-acting antacids or an H2-receptor antagonist. Administer at least 6 hours before or 10 hours after taking an H2-receptor antagonist.

• dasatinib

  sodium bicarbonate will decrease the level or effect of dasatinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  omeprazole will decrease the level or effect of dasatinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• demeclocycline

  sodium bicarbonate decreases levels of demeclocycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• digoxin

  omeprazole will increase the level or effect of digoxin by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• digoxin

  sodium bicarbonate will increase the level or effect of digoxin by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• doxycycline

  sodium bicarbonate decreases levels of doxycycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• duloxetine

  omeprazole will decrease the level or effect of duloxetine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.

• eltrombopag

  sodium bicarbonate decreases levels of eltrombopag by inhibition of GI absorption. Applies only to oral form of both agents. Contraindicated. Separate by at least 4 hours.

• enzalutamide

  enzalutamide will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erdafitinib

  omeprazole will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

• fedratinib

  omeprazole will increase the level or effect of fedratinib by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of fedratinib (a CYP3A4 and CYP2C19 substrate) with dual CYP3A4 and CYP2C19 inhibitor. Effect of coadministration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib has not been studied.

• fexinidazole

  fexinidazole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

• fleroxacin

  sodium bicarbonate decreases levels of fleroxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• fluvoxamine

  fluvoxamine will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.

• gemifloxacin

  sodium bicarbonate decreases levels of gemifloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• idelalisib

  idelalisib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

• indinavir

  omeprazole will decrease the level or effect of indinavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  sodium bicarbonate will decrease the level or effect of indinavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• infigratinib

  omeprazole will decrease the level or effect of infigratinib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• itraconazole

  sodium bicarbonate will decrease the level or effect of itraconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• isoniazid

  isoniazid will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.

• itraconazole

  omeprazole will decrease the level or effect of itraconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• ivosidenib

  ivosidenib will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

• ketoconazole

  omeprazole will decrease the level or effect of ketoconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  sodium bicarbonate will decrease the level or effect of ketoconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• levofloxacin

  sodium bicarbonate decreases levels of levofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• levoketoconazole

  omeprazole will decrease the level or effect of levoketoconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• levoketoconazole

  sodium bicarbonate will decrease the level or effect of levoketoconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• lonafarnib

  omeprazole will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.
  
  lonafarnib will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug. Lonafarnib may increase the AUC and peak concentration of CYP2C19 substrates. If coadministration unavoidable, monitor for adverse reactions and reduce the CYP2C19 substrate dose in accordance with its approved product labeling.

• mesalamine

  omeprazole decreases effects of mesalamine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Applies only to sustained release dosage form.

• minocycline

  sodium bicarbonate decreases levels of minocycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• moxifloxacin

  sodium bicarbonate decreases levels of moxifloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• neratinib

  omeprazole will decrease the level or effect of neratinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• nilotinib

  omeprazole will decrease the level or effect of nilotinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Nilotinib has a pH-dependent solubility and solubility is decreased at higher pH; separating doses may not eliminate this effect because of PPI extended duration of action

• nimodipine

  sodium bicarbonate will increase the level or effect of nimodipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• nisoldipine

  sodium bicarbonate will increase the level or effect of nisoldipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  omeprazole will increase the level or effect of nisoldipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• nitrendipine

  sodium bicarbonate will increase the level or effect of nitrendipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• pazopanib

  omeprazole will decrease the level or effect of pazopanib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with drugs that raise gastric pH; consider short-acting antacids in place of PPIs and H2 antagonists; separate antacid and pazopanib dosing by several hours

• ofloxacin

  sodium bicarbonate decreases levels of ofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• oxytetracycline

  sodium bicarbonate decreases levels of oxytetracycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• pexidartinib

  omeprazole will decrease the level or effect of pexidartinib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Avoid coadministration of proton pump inhibitors (PPIs) with pexidartinib. Use H2-receptor antagonists or antacids if needed. When using alternatives to PPIs, administer pexidartinib 2 hr before or after taking locally-acting antacids OR administer pexidartinib at least 2 hr before or 10 hr after taking an H2-receptor antagonist.

• phenobarbital

  phenobarbital will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifampin

  rifampin will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifapentine

  rifapentine will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• secobarbital

  secobarbital will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• secretin

  omeprazole, secretin. Other (see comment). Avoid or Use Alternate Drug. Comment: Concomitant use of PPIs may cause a hyperresponse in gastrin secretion in response to stimulation testing with secretin, falsely suggesting gastrinoma. The time it takes for serum gastrin concentrations to return to baseline following discontinuation of PPIs is specific to the individual PPI. Temporarily stop omeprazole treatment at least 14 days before assessing to allow gastrin levels to return to baseline.

• siponimod

  omeprazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• sofosbuvir/velpatasvir

  omeprazole will decrease the level or effect of sofosbuvir/velpatasvir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Velpatasvir solubility decreases as gastric pH increases (practically insoluble at pH >5). Coadministration of sofosbuvir/velpatasvir with omeprazole or other PPIs is not recommended. If considered medically necessary, give sofosbuvir/velpatasvir with food 4 hr before omeprazole 20 mg. Use with other PPIs has not been studied.

• sotorasib

  omeprazole will decrease the level or effect of sotorasib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. If use with an acid-reducing agent cannot be avoided, administer sotorasib 4 hr before or 10 hr after administration of a locally-acting antacid.

• sparsentan

  omeprazole decreases effects of sparsentan by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Proton pump inhibitors may decrease sparsentan exposure which may reduce efficacy of sparsentan.

• tetracycline

  sodium bicarbonate decreases levels of tetracycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• tucatinib

  tucatinib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

Monitor Closely (175)

• abrocitinib

  omeprazole will increase the level or effect of abrocitinib by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Start abrocitinib 50 mg qDay when coadministered with CYP2C19 inhibitors. If adequate response not achieved after 12 weeks, may increase to 100 mg qDay. Discontinue if inadequate response after dosage increase.

• acebutolol

  sodium bicarbonate decreases levels of acebutolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• alendronate

  sodium bicarbonate decreases levels of alendronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• allopurinol

  sodium bicarbonate decreases levels of allopurinol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• amantadine

  sodium bicarbonate will increase the level or effect of amantadine by Other (see comment). Modify Therapy/Monitor Closely. Urine pH changes towards alkalinic conditions may lead to an accumulation of amantadine with a possible increase in adverse reactions. Monitor for adverse reactions of amantadine.

• amobarbital

  amobarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• ampicillin

  omeprazole will decrease the level or effect of ampicillin by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of ampicillin by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• armodafinil

  armodafinil will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• atenolol

  sodium bicarbonate decreases levels of atenolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• avapritinib

  omeprazole will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• axitinib

  omeprazole increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• azithromycin

  sodium bicarbonate decreases levels of azithromycin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• bearberry

  sodium bicarbonate will increase the level or effect of bearberry by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• belumosudil

  omeprazole will decrease the level or effect of belumosudil by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Increase belumosudil dosage to 200 mg PO BID when coadministered with proton pump inhibitors.

• belzutifan

  omeprazole will increase the level or effect of belzutifan by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Belzutifan is a CYP2C19 substrate. Coadministration with CYP2C19 inhibitors may increase incidence or severity of adverse effects. Monitor for anemia and hypoxia and reduce belzutifan dose as recommended.

• benazepril

  sodium bicarbonate decreases effects of benazepril by unspecified interaction mechanism. Use Caution/Monitor.

• bendamustine

  omeprazole decreases levels of bendamustine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Concentrations of active metabolites may be increased.

• benzphetamine

  sodium bicarbonate will increase the level or effect of benzphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• betaxolol

  sodium bicarbonate decreases levels of betaxolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• bisoprolol

  sodium bicarbonate decreases levels of bisoprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• bortezomib

  bortezomib will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• bosutinib

  omeprazole decreases levels of bosutinib by Other (see comment). Use Caution/Monitor. Comment: PPIs may decrease bosutinib concentration by ~45%; bosutinib displays pH-dependent solubility.

• budesonide

  omeprazole decreases effects of budesonide by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Enteric-coated budesonide dissolves at pH >5.5. Also, dissolution of extended-release budesonide tablets is pH dependent. Coadministration with drugs that increase gastric pH may cause these budesonide products to prematurely dissolve, and possibly affect release properties and absorption of the drug in the duodenum.

• butabarbital

  butabarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• butalbital

  butalbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• cannabidiol

  omeprazole will increase the level or effect of cannabidiol by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider reducing the cannabidiol dose when coadministered with a strong CYP2C19 inhibitor.
  
  cannabidiol will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider reducing the dose of sensitive CYP2C19 substrates, as clinically appropriate, when coadministered with cannabidiol.

• capecitabine

  omeprazole decreases effects of capecitabine by unknown mechanism. Use Caution/Monitor. Retrospective data suggest elevated gastric pH caused by PPI use may impair capecitabine tablet dissolution and/or reduce absorption.

• captopril

  sodium bicarbonate decreases effects of captopril by unspecified interaction mechanism. Use Caution/Monitor. Sodium bicarbonate may decrease absorption of captopril.

• carbamazepine

  carbamazepine will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• carbonyl iron

  sodium bicarbonate will decrease the level or effect of carbonyl iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  omeprazole will decrease the level or effect of carbonyl iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• carvedilol

  sodium bicarbonate decreases levels of carvedilol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• cefpodoxime

  omeprazole decreases effects of cefpodoxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• cefdinir

  sodium bicarbonate will decrease the level or effect of cefdinir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• cefditoren

  sodium bicarbonate will decrease the level or effect of cefditoren by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• cefpodoxime

  sodium bicarbonate will decrease the level or effect of cefpodoxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• cefuroxime

  sodium bicarbonate will decrease the level or effect of cefuroxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  omeprazole decreases effects of cefuroxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• celecoxib

  sodium bicarbonate decreases levels of celecoxib by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• cenobamate

  cenobamate will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.
  
  cenobamate will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider a dose reduction of CYP2C19 substrates, as clinically appropriate, when used concomitantly with cenobamate.

• celiprolol

  sodium bicarbonate decreases levels of celiprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• chenodiol

  sodium bicarbonate decreases levels of chenodiol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• chloroquine

  sodium bicarbonate will decrease the level or effect of chloroquine by Mechanism: inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Separate doses by at least 4 hr

• ciprofloxacin

  sodium bicarbonate decreases levels of ciprofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. A large proportion of ciprofloxacin is normally excreted unchanged in the urine. When urinary alkalinizing agents such as sodium bicarbonate are used concomitantly, the solubility of ciprofloxacin can be decreased because of alkaline urine. Patients should be monitored for crystalluria and nephrotoxicity.
  
  omeprazole will decrease the level or effect of ciprofloxacin by unknown mechanism. Use Caution/Monitor. Absorption of the ciprofloxacin ER tablet was slightly diminished (20%) when coadministered with omeprazole.

• citalopram

  omeprazole will increase the level or effect of citalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Citalopram 20 mg/day is the maximum recommended dose for patients taking CYP2C19 inhibitors because of the risk of QT prolongation.

• crizotinib

  sodium bicarbonate decreases levels of crizotinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Drugs that elevate the gastric pH may decrease the solubility of crizotinib and subsequently reduce its bioavailability. However, no formal studies have been conducted. .

• clobazam

  omeprazole will increase the level or effect of clobazam by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Dosage adjustment may be required; CYP2C19 inhibitors may result in increased exposure to N-desmethylclobazam (active metabolite).

• clozapine

  omeprazole will decrease the level or effect of clozapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• cobicistat

  cobicistat will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conivaptan

  conivaptan will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• crizotinib

  omeprazole will decrease the level or effect of crizotinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Drugs that elevate the gastric pH may decrease the solubility of crizotinib and subsequently reduce its bioavailability. However, no formal studies have been conducted.

• cyclosporine

  omeprazole, cyclosporine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Long-term use of PPIs may cause hypomagnesemia and increase this risk when coadministered with drugs that may also decrease magnesium levels.

• dabrafenib

  omeprazole will decrease the level or effect of dabrafenib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Drugs that alter upper GI tract pH (eg, PPIs, H2-blockers, antacids) may decrease dabrafenib solubility and reduce its bioavailability
  
  dabrafenib will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Use alternative if available

• deferoxamine

  deferoxamine decreases levels of sodium bicarbonate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Deferoxamine chelates iron; its affinity for other minerals is unknown.

• deflazacort

  sodium bicarbonate and deflazacort both decrease serum potassium. Use Caution/Monitor.

• dextroamphetamine

  sodium bicarbonate will increase the level or effect of dextroamphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
  
  omeprazole, dextroamphetamine. Other (see comment). Use Caution/Monitor. Comment: Reduced gastric acidity caused by proton pump inhibitors decreases time to Tmax for amphetamine and dextroamphetamine. AUC was unaffected. .

• diazepam intranasal

  omeprazole will increase the level or effect of diazepam intranasal by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Strong or moderate CYP2C19 inhibitors may decrease rate of diazepam elimination, thereby increasing adverse reactions to diazepam.

• enalapril

  sodium bicarbonate decreases effects of enalapril by unspecified interaction mechanism. Use Caution/Monitor.

• dichlorphenamide

  dichlorphenamide and omeprazole both decrease serum potassium. Use Caution/Monitor.

• digoxin

  omeprazole increases toxicity of digoxin by Other (see comment). Use Caution/Monitor. Comment: Prolonged use of PPIs may cause hypomagnesemia and increase risk for digoxin toxicity.

• efavirenz

  efavirenz will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  efavirenz will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• elagolix

  elagolix will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak inhibitor of CYP2C19. No dose adjustments are needed for omeprazole with 40 mg/day or less. Consider omeprazole dose reduction with higher omeprazole doses (eg, dose for Zollinger-Ellison) if coadministered with elagolix.
  
  elagolix decreases levels of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• eltrombopag

  omeprazole will decrease the level or effect of eltrombopag by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• eluxadoline

  omeprazole increases levels of eluxadoline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. As a precautionary measure due to incomplete information on the metabolism of eluxadoline, use caution when coadministered with strong CYP2C19 inhibitors.

• encorafenib

  encorafenib, omeprazole. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

• ephedrine

  sodium bicarbonate will increase the level or effect of ephedrine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• erythromycin base

  sodium bicarbonate increases levels of erythromycin base by unknown mechanism. Use Caution/Monitor.

• erythromycin ethylsuccinate

  sodium bicarbonate increases levels of erythromycin ethylsuccinate by unknown mechanism. Use Caution/Monitor.

• erythromycin lactobionate

  sodium bicarbonate increases levels of erythromycin lactobionate by unknown mechanism. Use Caution/Monitor.

• erythromycin stearate

  sodium bicarbonate increases levels of erythromycin stearate by unknown mechanism. Use Caution/Monitor.

• escitalopram

  omeprazole will increase the level or effect of escitalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• eslicarbazepine acetate

  eslicarbazepine acetate will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• esmolol

  sodium bicarbonate decreases levels of esmolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• etidronate

  sodium bicarbonate decreases levels of etidronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• etravirine

  etravirine will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• fedratinib

  fedratinib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• ferric gluconate

  omeprazole will decrease the level or effect of ferric gluconate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ferric maltol

  sodium bicarbonate will decrease the level or effect of ferric maltol by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  omeprazole will decrease the level or effect of ferric maltol by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ferrous fumarate

  omeprazole will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ferrous gluconate

  omeprazole will decrease the level or effect of ferrous gluconate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of ferrous gluconate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ferrous sulfate

  omeprazole will decrease the level or effect of ferrous sulfate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of ferrous sulfate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• fexinidazole

  fexinidazole will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• flecainide

  sodium bicarbonate will increase the level or effect of flecainide by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• finerenone

  omeprazole will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or weak CYP3A4 inhibitors. Adjust finererone dosage as needed.

• flibanserin

  omeprazole will increase the level or effect of flibanserin by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Coadministration of flibanserin with strong CYP2C19 inhibitors may increase flibanserin exposure and increase the risk of hypotension, syncope, and CNS depression.
  
  omeprazole will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.

• fluconazole

  fluconazole will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• fosamprenavir

  omeprazole will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• fosinopril

  sodium bicarbonate decreases effects of fosinopril by unspecified interaction mechanism. Use Caution/Monitor.

• fosphenytoin

  omeprazole will increase the level or effect of fosphenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  fosphenytoin will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• gabapentin

  sodium bicarbonate decreases levels of gabapentin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• gabapentin enacarbil

  sodium bicarbonate decreases levels of gabapentin enacarbil by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• gefitinib

  omeprazole decreases levels of gefitinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Avoid coadministration of gefitinib with PPIs if possible. If treatment with a PPI is required, separate gefitinib and PPI doses by 12 hr.

• glipizide

  sodium bicarbonate will increase the level or effect of glipizide by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• glyburide

  omeprazole will increase the level or effect of glyburide by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  sodium bicarbonate will increase the level or effect of glyburide by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ibandronate

  sodium bicarbonate decreases levels of ibandronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• iloperidone

  iloperidone increases levels of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

• imidapril

  sodium bicarbonate decreases effects of imidapril by unspecified interaction mechanism. Use Caution/Monitor.

• imipramine

  omeprazole will increase the level or effect of imipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• iron dextran complex

  omeprazole will decrease the level or effect of iron dextran complex by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of iron dextran complex by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• iron sucrose

  omeprazole will decrease the level or effect of iron sucrose by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of iron sucrose by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• isavuconazonium sulfate

  omeprazole will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isoniazid

  sodium bicarbonate decreases levels of isoniazid by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• istradefylline

  istradefylline will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

• itraconazole

  sodium bicarbonate decreases levels of itraconazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• ketoconazole

  sodium bicarbonate decreases levels of ketoconazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• labetalol

  sodium bicarbonate decreases levels of labetalol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• lactulose

  sodium bicarbonate decreases effects of lactulose by pharmacodynamic antagonism. Use Caution/Monitor.

• ledipasvir/sofosbuvir

  omeprazole decreases levels of ledipasvir/sofosbuvir by Other (see comment). Use Caution/Monitor. Comment: Ledipasvir solubility decreases as pH increases; drugs that increase gastric pH are expected to decrease levels of ledipasvir; proton-pump inhibitor doses comparable to omeprazole <20 mg can be administered simultaneously with ledipasvir/sofosbuvir under fasted conditions.

• lemborexant

  omeprazole will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.

• letermovir

  letermovir increases levels of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor and dose adjustment may be necessary.

• levoketoconazole

  sodium bicarbonate decreases levels of levoketoconazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• lisinopril

  sodium bicarbonate decreases effects of lisinopril by unspecified interaction mechanism. Use Caution/Monitor.

• lomitapide

  omeprazole increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.

• losartan

  omeprazole will increase the level or effect of losartan by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. May inhibit the conversion of losartan to its active metabolite E-3174. Importance of interaction not established; monitor individual therapeutic response to determine losartan dosage.

• lumacaftor/ivacaftor

  lumacaftor/ivacaftor, omeprazole. affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. In vitro studies suggest that lumacaftor may induce and ivacaftor may inhibit CYP2C19 substrates. .
  
  lumacaftor/ivacaftor will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lumacaftor/ivacaftor is a strong CYP3A4 inhibitor and also has the potential to induce CYP2C19 and both induce and inhibitor P-gp.

• memantine

  sodium bicarbonate will increase the level or effect of memantine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• methotrexate

  omeprazole increases levels of methotrexate by decreasing renal clearance. Use Caution/Monitor. Temporary withdrawal of PPI may be considered in some patients.

• methscopolamine

  sodium bicarbonate decreases levels of methscopolamine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

• methylphenidate

  omeprazole decreases effects of methylphenidate by enhancing GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Since the characteristics of methylphenidate extended release capsules (Ritalin LA) are pH dependent, coadministration of antacids or acid suppressants could alter the release of methylphenidate. Consider separating the administration of the antacid and the methylphenidate extended-release capsules may be avoided.

• metoprolol

  sodium bicarbonate decreases levels of metoprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• mexiletine

  sodium bicarbonate will increase the level or effect of mexiletine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• midazolam intranasal

  omeprazole will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.

• modafinil

  modafinil will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• moexipril

  sodium bicarbonate decreases effects of moexipril by unspecified interaction mechanism. Use Caution/Monitor.

• mycophenolate

  omeprazole will decrease the level or effect of mycophenolate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Potential interaction applies to mycophenolate mofetil. Enteric coated mycophenolate sodium formulation is less sensitive to this interaction. Clinical significance unclear.
  
  sodium bicarbonate will decrease the level or effect of mycophenolate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• nadolol

  sodium bicarbonate decreases levels of nadolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• nateglinide

  omeprazole will increase the level or effect of nateglinide by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• nebivolol

  sodium bicarbonate decreases levels of nebivolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• nitrofurantoin

  sodium bicarbonate decreases levels of nitrofurantoin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• omadacycline

  sodium bicarbonate will decrease the level or effect of omadacycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.

• ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)

  ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) will decrease the level or effect of omeprazole by unspecified interaction mechanism. Use Caution/Monitor. Monitor for decreased omeprazole efficacy; consider increasing omeprazole dose in patients whose symptoms are not well controlled (not to exceed 40 mg/day)

• oxcarbazepine

  oxcarbazepine will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• pamidronate

  sodium bicarbonate decreases levels of pamidronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• penbutolol

  sodium bicarbonate decreases levels of penbutolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• penicillamine

  sodium bicarbonate decreases levels of penicillamine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• pentobarbital

  pentobarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• perindopril

  sodium bicarbonate decreases effects of perindopril by unspecified interaction mechanism. Use Caution/Monitor.

• phenobarbital

  phenobarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• phenytoin

  omeprazole will increase the level or effect of phenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  phenytoin will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• pindolol

  sodium bicarbonate decreases levels of pindolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• polysaccharide iron

  omeprazole will decrease the level or effect of polysaccharide iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of polysaccharide iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• posaconazole

  omeprazole will decrease the level or effect of posaconazole by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  posaconazole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of posaconazole by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• primidone

  primidone will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  primidone will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• propranolol

  sodium bicarbonate decreases levels of propranolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• pseudoephedrine

  sodium bicarbonate will increase the level or effect of pseudoephedrine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor. Caution advised with frequent or high dose antacids

• quinapril

  sodium bicarbonate decreases effects of quinapril by unspecified interaction mechanism. Use Caution/Monitor.

• quinidine

  sodium bicarbonate will increase the level or effect of quinidine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor. Elevated quinidine plasma levels, possibly with cardiac conduction disturbances and arrhythmias, may occur.

• ramipril

  sodium bicarbonate decreases effects of ramipril by unspecified interaction mechanism. Use Caution/Monitor.

• rifampin

  rifampin will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of rifampin by Other (see comment). Use Caution/Monitor. Concomitant antacid administration may reduce absorption of rifampin; daily doses of rifampin should be given at least 1 hr before ingestion of antacids

• riociguat

  sodium bicarbonate decreases levels of riociguat by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate administration by at least 1 hour.
  
  omeprazole will decrease the level or effect of riociguat by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• risedronate

  sodium bicarbonate decreases levels of risedronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• ritonavir

  ritonavir will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• roflumilast

  omeprazole will decrease the level or effect of roflumilast by affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Concomitant therapy may reduce therapeutic effectiveness.

• rose hips

  omeprazole will decrease the level or effect of rose hips by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of rose hips by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• rosuvastatin

  sodium bicarbonate decreases levels of rosuvastatin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• secobarbital

  secobarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• sarecycline

  sodium bicarbonate will decrease the level or effect of sarecycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.

• sodium sulfate/potassium chloride/magnesium sulfate/polyethylene glycol

  sodium bicarbonate and sodium sulfate/potassium chloride/magnesium sulfate/polyethylene glycol both decrease serum potassium. Modify Therapy/Monitor Closely.

• sotalol

  sodium bicarbonate decreases levels of sotalol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• sparsentan

  sparsentan will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Sparsentan (a CYP2C19 inducer) decreases exposure of CYP2C19 substrates and reduces efficacy related to these substrates.

• St John's Wort

  St John's Wort will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• stiripentol

  stiripentol, omeprazole. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
  
  stiripentol will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider reducing the dose of CYP2C19 substrates, if adverse reactions are experienced when administered concomitantly with stiripentol.

• tacrolimus

  omeprazole will increase the level or effect of tacrolimus by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Concomitant administration may increase tacrolimus whole blood concentrations, particularly in intermediate or poor metabolizers of CYP2C19

• tamoxifen

  omeprazole will increase the level or effect of tamoxifen by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• tazemetostat

  tazemetostat will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  omeprazole will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tiludronate

  sodium bicarbonate decreases levels of tiludronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• timolol

  sodium bicarbonate decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• tinidazole

  omeprazole will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tofacitinib

  omeprazole increases levels of tofacitinib by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. No specific dose adjustment recommended when tofacitinib coadministered with potent CYP2C19 inhibitors; decrease tofacitinib dose if coadministered with both moderate CYP3A4 and potent CYP2C19 inhibitors .

• tolbutamide

  sodium bicarbonate will increase the level or effect of tolbutamide by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• trandolapril

  sodium bicarbonate decreases effects of trandolapril by unspecified interaction mechanism. Use Caution/Monitor.

• triclabendazole

  triclabendazole will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• ursodiol

  sodium bicarbonate decreases effects of ursodiol by pharmacodynamic antagonism. Use Caution/Monitor.

• vismodegib

  omeprazole will decrease the level or effect of vismodegib by Other (see comment). Use Caution/Monitor. Drugs that increase gastric pH alter vismodegib solubility and therefore reduce bioavailability; effect on efficacy unknown

• voriconazole

  voriconazole will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  voriconazole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• warfarin

  omeprazole will increase the level or effect of warfarin by Other (see comment). Use Caution/Monitor. Warfarin's less potent R-enantiomer is metabolized in part by CYP3A4 (and also CYP1A2 and CYP2C19). Monitor INR more frequently if coadministered with inhibitors of these isoenzymes and adjust warfarin dose if needed.

• zoledronic acid

  sodium bicarbonate decreases levels of zoledronic acid by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

Minor (72)

• acetazolamide

  acetazolamide will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alosetron

  omeprazole will decrease the level or effect of alosetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• alprazolam

  omeprazole increases levels of alprazolam by decreasing metabolism. Minor/Significance Unknown.

• ambrisentan

  omeprazole will increase the level or effect of ambrisentan by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• anastrozole

  anastrozole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• aspirin

  sodium bicarbonate, aspirin. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• aspirin rectal

  sodium bicarbonate, aspirin rectal. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• aspirin/citric acid/sodium bicarbonate

  sodium bicarbonate, aspirin/citric acid/sodium bicarbonate. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• balsalazide

  sodium bicarbonate, balsalazide. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• bismuth subsalicylate

  omeprazole increases levels of bismuth subsalicylate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• blessed thistle

  blessed thistle decreases effects of omeprazole by pharmacodynamic antagonism. Minor/Significance Unknown. Theoretical interaction.
  
  blessed thistle decreases effects of sodium bicarbonate by pharmacodynamic antagonism. Minor/Significance Unknown. Theoretical interaction.

• bosentan

  omeprazole will increase the level or effect of bosentan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
  
  bosentan will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• choline magnesium trisalicylate

  sodium bicarbonate, choline magnesium trisalicylate. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• carbamazepine

  omeprazole increases levels of carbamazepine by decreasing metabolism. Minor/Significance Unknown. Monitor plasma levels when used concomitantly.

• carvedilol

  omeprazole will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• chlordiazepoxide

  omeprazole increases levels of chlordiazepoxide by decreasing metabolism. Minor/Significance Unknown.

• chromium

  sodium bicarbonate decreases levels of chromium by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. Separate by 2 hours.

• clomipramine

  omeprazole will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• clonazepam

  omeprazole increases levels of clonazepam by decreasing metabolism. Minor/Significance Unknown.

• clorazepate

  omeprazole increases levels of clorazepate by decreasing metabolism. Minor/Significance Unknown.

• cyanocobalamin

  omeprazole decreases levels of cyanocobalamin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• cyclophosphamide

  cyclophosphamide will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• darifenacin

  darifenacin will decrease the level or effect of omeprazole by Other (see comment). Minor/Significance Unknown. Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents

• devil's claw

  devil's claw decreases effects of sodium bicarbonate by pharmacodynamic antagonism. Minor/Significance Unknown.
  
  devil's claw decreases effects of omeprazole by pharmacodynamic antagonism. Minor/Significance Unknown.

• dexamethasone

  dexamethasone will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• diflunisal

  sodium bicarbonate, diflunisal. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• diazepam

  omeprazole will increase the level or effect of diazepam by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• dronedarone

  dronedarone will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  elvitegravir/cobicistat/emtricitabine/tenofovir DF, omeprazole. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. Based on drug interaction studies conducted with the components of Stribild, no clinically significant drug interactions have been either observed or are expected when coadministered with PPIs.

• eslicarbazepine acetate

  eslicarbazepine acetate decreases effects of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. Monitor for GI symptoms; net increased or decreased effect on PPI action unclear due to opposing CYP450 actions.

• estazolam

  omeprazole increases levels of estazolam by decreasing metabolism. Minor/Significance Unknown.

• etravirine

  omeprazole will increase the level or effect of etravirine by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.
  
  omeprazole will increase the level or effect of etravirine by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• ferric carboxymaltose

  omeprazole will decrease the level or effect of ferric carboxymaltose by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown.

• fluoxetine

  fluoxetine will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• flurazepam

  omeprazole increases levels of flurazepam by decreasing metabolism. Minor/Significance Unknown.

• fluvastatin

  omeprazole will increase the level or effect of fluvastatin by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• glipizide

  omeprazole will increase the level or effect of glipizide by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• ibuprofen IV

  omeprazole will increase the level or effect of ibuprofen IV by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• larotrectinib

  larotrectinib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• levoketoconazole

  levoketoconazole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• levothyroxine

  omeprazole decreases levels of levothyroxine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.

• lidocaine

  omeprazole will decrease the level or effect of lidocaine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• liothyronine

  omeprazole decreases levels of liothyronine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.

• liotrix

  omeprazole decreases levels of liotrix by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.

• lisdexamfetamine

  omeprazole, lisdexamfetamine. Other (see comment). Minor/Significance Unknown. Comment: Reduced gastric acidity caused by proton pump inhibitors decreases time to Tmax for amphetamine and dextroamphetamine. AUC was unaffected. .

• lorazepam

  omeprazole increases levels of lorazepam by decreasing metabolism. Minor/Significance Unknown.

• mesalamine

  sodium bicarbonate, mesalamine. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• methamphetamine

  omeprazole decreases levels of methamphetamine by Other (see comment). Minor/Significance Unknown. Comment: Time to maximum concentration (Tmax) of amphetamine is decreased compared to when administered alone; monitor patients for changes in clinical effect and adjust therapy based on clinical response.

• mexiletine

  omeprazole will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• midazolam

  omeprazole increases levels of midazolam by decreasing metabolism. Minor/Significance Unknown.

• mitotane

  mitotane decreases levels of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

• olanzapine

  omeprazole will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• ospemifene

  omeprazole increases levels of ospemifene by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• phytoestrogens

  omeprazole decreases levels of phytoestrogens by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• ponatinib

  omeprazole decreases levels of ponatinib by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown.

• quazepam

  omeprazole increases levels of quazepam by decreasing metabolism. Minor/Significance Unknown.

• ribociclib

  ribociclib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• riluzole

  omeprazole will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• ruxolitinib

  omeprazole will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ruxolitinib topical

  omeprazole will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• salicylates (non-asa)

  sodium bicarbonate, salicylates (non-asa). Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• salsalate

  sodium bicarbonate, salsalate. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• strontium ranelate

  sodium bicarbonate decreases levels of strontium ranelate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. Separate by 2 hr when possible.

• sulfamethoxazole

  omeprazole will increase the level or effect of sulfamethoxazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• sulfasalazine

  sodium bicarbonate, sulfasalazine. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• theophylline

  omeprazole will decrease the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
  
  omeprazole increases toxicity of theophylline by Other (see comment). Minor/Significance Unknown. Comment: Prolonged use of proton pump inhibitors can cause hypochlorhydria, which in turn causes peristalsis in small intestine to increase and peristalsis in the proximal colon to decrease; monitor for toxicity.

• thyroid desiccated

  omeprazole decreases levels of thyroid desiccated by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.

• tizanidine

  omeprazole will decrease the level or effect of tizanidine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• tolbutamide

  omeprazole will increase the level or effect of tolbutamide by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• triazolam

  omeprazole increases levels of triazolam by decreasing metabolism. Minor/Significance Unknown.

• voriconazole

  omeprazole will increase the level or effect of voriconazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• willow bark

  sodium bicarbonate, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• abrocitinib

  Monitor Closely (1)omeprazole will increase the level or effect of abrocitinib by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Start abrocitinib 50 mg qDay when coadministered with CYP2C19 inhibitors. If adequate response not achieved after 12 weeks, may increase to 100 mg qDay. Discontinue if inadequate response after dosage increase.Serious - Use Alternative (1)omeprazole will increase the level or effect of abrocitinib by decreasing metabolism. Avoid or Use Alternate Drug. Abrocitinib is a CYP2C9 and CYP2C19 substrate. Drugs that are moderate-to-strong inhibitors of both CYP2C9 and CYP2C19 increase systemic exposure of abrocitinib and its active metabolites, which may increase adverse effects.

• acalabrutinib

  Serious - Use Alternative (1)omeprazole decreases levels of acalabrutinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Acalabrutinib solubility decreases with increasing gastric pH. Due to the long-lasting effect of PPIs, separation of doses may not eliminate the interaction.

• acebutolol

  Monitor Closely (1)sodium bicarbonate decreases levels of acebutolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• acetazolamide

  Minor (1)acetazolamide will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alendronate

  Monitor Closely (1)sodium bicarbonate decreases levels of alendronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• allopurinol

  Monitor Closely (1)sodium bicarbonate decreases levels of allopurinol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• alosetron

  Minor (1)omeprazole will decrease the level or effect of alosetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• alprazolam

  Minor (1)omeprazole increases levels of alprazolam by decreasing metabolism. Minor/Significance Unknown.

• amantadine

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of amantadine by Other (see comment). Modify Therapy/Monitor Closely. Urine pH changes towards alkalinic conditions may lead to an accumulation of amantadine with a possible increase in adverse reactions. Monitor for adverse reactions of amantadine.

• ambrisentan

  Minor (1)omeprazole will increase the level or effect of ambrisentan by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• amobarbital

  Monitor Closely (1)amobarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• ampicillin

  Monitor Closely (2)omeprazole will decrease the level or effect of ampicillin by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of ampicillin by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• anastrozole

  Minor (1)anastrozole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• apalutamide

  Serious - Use Alternative (2)apalutamide will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP2C19 inducer, with drugs that are CYP2C19 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered.
  
  apalutamide will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

• armodafinil

  Monitor Closely (1)armodafinil will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• aspirin

  Minor (1)sodium bicarbonate, aspirin. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• aspirin rectal

  Minor (1)sodium bicarbonate, aspirin rectal. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• aspirin/citric acid/sodium bicarbonate

  Minor (1)sodium bicarbonate, aspirin/citric acid/sodium bicarbonate. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• atazanavir

  Serious - Use Alternative (2)sodium bicarbonate will decrease the level or effect of atazanavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  omeprazole will decrease the level or effect of atazanavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Atazanavir solubility decreases as pH increases. Substantially reduced plasma concentrations of atazanavir are expected if PPIs are coadministered. PPI dose should not exceed a dose comparable to omeprazole 20 mg and must be taken ~12 h before atazanavir/ritonavir in treatment naive-patients. PPIs are not recommended in treatment-experienced taking atazanavir.

• atenolol

  Monitor Closely (1)sodium bicarbonate decreases levels of atenolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• avapritinib

  Monitor Closely (1)omeprazole will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• axitinib

  Monitor Closely (1)omeprazole increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• azithromycin

  Monitor Closely (1)sodium bicarbonate decreases levels of azithromycin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• balsalazide

  Minor (1)sodium bicarbonate, balsalazide. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• bearberry

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of bearberry by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• belumosudil

  Monitor Closely (1)omeprazole will decrease the level or effect of belumosudil by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Increase belumosudil dosage to 200 mg PO BID when coadministered with proton pump inhibitors.

• belzutifan

  Monitor Closely (1)omeprazole will increase the level or effect of belzutifan by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Belzutifan is a CYP2C19 substrate. Coadministration with CYP2C19 inhibitors may increase incidence or severity of adverse effects. Monitor for anemia and hypoxia and reduce belzutifan dose as recommended.

• benazepril

  Monitor Closely (1)sodium bicarbonate decreases effects of benazepril by unspecified interaction mechanism. Use Caution/Monitor.

• bendamustine

  Monitor Closely (1)omeprazole decreases levels of bendamustine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Concentrations of active metabolites may be increased.

• benzphetamine

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of benzphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• betaxolol

  Monitor Closely (1)sodium bicarbonate decreases levels of betaxolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• bismuth subsalicylate

  Minor (1)omeprazole increases levels of bismuth subsalicylate by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• bisoprolol

  Monitor Closely (1)sodium bicarbonate decreases levels of bisoprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• blessed thistle

  Minor (2)blessed thistle decreases effects of omeprazole by pharmacodynamic antagonism. Minor/Significance Unknown. Theoretical interaction.
  
  blessed thistle decreases effects of sodium bicarbonate by pharmacodynamic antagonism. Minor/Significance Unknown. Theoretical interaction.

• bortezomib

  Monitor Closely (1)bortezomib will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• bosentan

  Minor (2)omeprazole will increase the level or effect of bosentan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.
  
  bosentan will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• bosutinib

  Monitor Closely (1)omeprazole decreases levels of bosutinib by Other (see comment). Use Caution/Monitor. Comment: PPIs may decrease bosutinib concentration by ~45%; bosutinib displays pH-dependent solubility.

• budesonide

  Monitor Closely (1)omeprazole decreases effects of budesonide by increasing gastric pH. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Enteric-coated budesonide dissolves at pH >5.5. Also, dissolution of extended-release budesonide tablets is pH dependent. Coadministration with drugs that increase gastric pH may cause these budesonide products to prematurely dissolve, and possibly affect release properties and absorption of the drug in the duodenum.

• butabarbital

  Monitor Closely (1)butabarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• butalbital

  Monitor Closely (1)butalbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• cannabidiol

  Monitor Closely (2)omeprazole will increase the level or effect of cannabidiol by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider reducing the cannabidiol dose when coadministered with a strong CYP2C19 inhibitor.
  
  cannabidiol will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider reducing the dose of sensitive CYP2C19 substrates, as clinically appropriate, when coadministered with cannabidiol.

• capecitabine

  Monitor Closely (1)omeprazole decreases effects of capecitabine by unknown mechanism. Use Caution/Monitor. Retrospective data suggest elevated gastric pH caused by PPI use may impair capecitabine tablet dissolution and/or reduce absorption.

• captopril

  Monitor Closely (1)sodium bicarbonate decreases effects of captopril by unspecified interaction mechanism. Use Caution/Monitor. Sodium bicarbonate may decrease absorption of captopril.

• carbamazepine

  Monitor Closely (1)carbamazepine will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)carbamazepine will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.Minor (1)omeprazole increases levels of carbamazepine by decreasing metabolism. Minor/Significance Unknown. Monitor plasma levels when used concomitantly.

• carbonyl iron

  Monitor Closely (2)sodium bicarbonate will decrease the level or effect of carbonyl iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  omeprazole will decrease the level or effect of carbonyl iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• carvedilol

  Monitor Closely (1)sodium bicarbonate decreases levels of carvedilol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.Minor (1)omeprazole will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• cefdinir

  Monitor Closely (1)sodium bicarbonate will decrease the level or effect of cefdinir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• cefditoren

  Monitor Closely (1)sodium bicarbonate will decrease the level or effect of cefditoren by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• cefpodoxime

  Monitor Closely (2)sodium bicarbonate will decrease the level or effect of cefpodoxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  omeprazole decreases effects of cefpodoxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• cefuroxime

  Monitor Closely (2)sodium bicarbonate will decrease the level or effect of cefuroxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  omeprazole decreases effects of cefuroxime by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• celecoxib

  Monitor Closely (1)sodium bicarbonate decreases levels of celecoxib by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• celiprolol

  Monitor Closely (1)sodium bicarbonate decreases levels of celiprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• cenobamate

  Monitor Closely (2)cenobamate will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.
  
  cenobamate will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider a dose reduction of CYP2C19 substrates, as clinically appropriate, when used concomitantly with cenobamate.

• ceritinib

  Serious - Use Alternative (1)omeprazole decreases effects of ceritinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• chenodiol

  Monitor Closely (1)sodium bicarbonate decreases levels of chenodiol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• chlordiazepoxide

  Minor (1)omeprazole increases levels of chlordiazepoxide by decreasing metabolism. Minor/Significance Unknown.

• chloroquine

  Monitor Closely (1)sodium bicarbonate will decrease the level or effect of chloroquine by Mechanism: inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Separate doses by at least 4 hr

• choline magnesium trisalicylate

  Minor (1)sodium bicarbonate, choline magnesium trisalicylate. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• chromium

  Minor (1)sodium bicarbonate decreases levels of chromium by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. Separate by 2 hours.

• cilostazol

  Serious - Use Alternative (1)omeprazole will increase the level or effect of cilostazol by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.

• ciprofloxacin

  Monitor Closely (2)sodium bicarbonate decreases levels of ciprofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. A large proportion of ciprofloxacin is normally excreted unchanged in the urine. When urinary alkalinizing agents such as sodium bicarbonate are used concomitantly, the solubility of ciprofloxacin can be decreased because of alkaline urine. Patients should be monitored for crystalluria and nephrotoxicity.
  
  omeprazole will decrease the level or effect of ciprofloxacin by unknown mechanism. Use Caution/Monitor. Absorption of the ciprofloxacin ER tablet was slightly diminished (20%) when coadministered with omeprazole.

• citalopram

  Monitor Closely (1)omeprazole will increase the level or effect of citalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Citalopram 20 mg/day is the maximum recommended dose for patients taking CYP2C19 inhibitors because of the risk of QT prolongation.

• clobazam

  Monitor Closely (1)omeprazole will increase the level or effect of clobazam by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Dosage adjustment may be required; CYP2C19 inhibitors may result in increased exposure to N-desmethylclobazam (active metabolite).

• clomipramine

  Minor (1)omeprazole will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• clonazepam

  Minor (1)omeprazole increases levels of clonazepam by decreasing metabolism. Minor/Significance Unknown.

• clopidogrel

  Serious - Use Alternative (1)omeprazole decreases effects of clopidogrel by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug. Clopidogrel efficacy may be reduced by drugs that inhibit CYP2C19. Inhibition of platelet aggregation by clopidogrel is entirely due to an active metabolite. Clopidogrel is metabolized to this active metabolite in part by CYP2C19. .

• clorazepate

  Minor (1)omeprazole increases levels of clorazepate by decreasing metabolism. Minor/Significance Unknown.

• clozapine

  Monitor Closely (1)omeprazole will decrease the level or effect of clozapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• cobicistat

  Monitor Closely (1)cobicistat will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conivaptan

  Monitor Closely (1)conivaptan will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• crizotinib

  Monitor Closely (2)omeprazole will decrease the level or effect of crizotinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Drugs that elevate the gastric pH may decrease the solubility of crizotinib and subsequently reduce its bioavailability. However, no formal studies have been conducted.
  
  sodium bicarbonate decreases levels of crizotinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Drugs that elevate the gastric pH may decrease the solubility of crizotinib and subsequently reduce its bioavailability. However, no formal studies have been conducted. .

• cyanocobalamin

  Minor (1)omeprazole decreases levels of cyanocobalamin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• cyclophosphamide

  Minor (1)cyclophosphamide will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• cyclosporine

  Monitor Closely (1)omeprazole, cyclosporine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Long-term use of PPIs may cause hypomagnesemia and increase this risk when coadministered with drugs that may also decrease magnesium levels.

• dabrafenib

  Monitor Closely (2)dabrafenib will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Use alternative if available
  
  omeprazole will decrease the level or effect of dabrafenib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Drugs that alter upper GI tract pH (eg, PPIs, H2-blockers, antacids) may decrease dabrafenib solubility and reduce its bioavailability

• dacomitinib

  Serious - Use Alternative (1)omeprazole will increase the level or effect of dacomitinib by unspecified interaction mechanism. Avoid or Use Alternate Drug. Concomitant use with a PPI decreases dacomitinib concentrations, which may reduce dacomitinib efficacy. Avoid use of PPIs with dacomitinib. As an alternative to PPIs, use locally-acting antacids or an H2-receptor antagonist. Administer at least 6 hours before or 10 hours after taking an H2-receptor antagonist.

• dapsone

  Serious - Use Alternative (1)sodium bicarbonate will decrease the level or effect of dapsone by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• darifenacin

  Minor (1)darifenacin will decrease the level or effect of omeprazole by Other (see comment). Minor/Significance Unknown. Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents

• dasatinib

  Serious - Use Alternative (2)sodium bicarbonate will decrease the level or effect of dasatinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  omeprazole will decrease the level or effect of dasatinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• deferoxamine

  Monitor Closely (1)deferoxamine decreases levels of sodium bicarbonate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Deferoxamine chelates iron; its affinity for other minerals is unknown.

• deflazacort

  Monitor Closely (1)sodium bicarbonate and deflazacort both decrease serum potassium. Use Caution/Monitor.

• demeclocycline

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of demeclocycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• devil's claw

  Minor (2)devil's claw decreases effects of sodium bicarbonate by pharmacodynamic antagonism. Minor/Significance Unknown.
  
  devil's claw decreases effects of omeprazole by pharmacodynamic antagonism. Minor/Significance Unknown.

• dexamethasone

  Minor (1)dexamethasone will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• dextroamphetamine

  Monitor Closely (2)omeprazole, dextroamphetamine. Other (see comment). Use Caution/Monitor. Comment: Reduced gastric acidity caused by proton pump inhibitors decreases time to Tmax for amphetamine and dextroamphetamine. AUC was unaffected. .
  
  sodium bicarbonate will increase the level or effect of dextroamphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• diazepam

  Minor (1)omeprazole will increase the level or effect of diazepam by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• diazepam intranasal

  Monitor Closely (1)omeprazole will increase the level or effect of diazepam intranasal by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Strong or moderate CYP2C19 inhibitors may decrease rate of diazepam elimination, thereby increasing adverse reactions to diazepam.

• dichlorphenamide

  Monitor Closely (1)dichlorphenamide and omeprazole both decrease serum potassium. Use Caution/Monitor.

• diflunisal

  Minor (1)sodium bicarbonate, diflunisal. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• digoxin

  Monitor Closely (1)omeprazole increases toxicity of digoxin by Other (see comment). Use Caution/Monitor. Comment: Prolonged use of PPIs may cause hypomagnesemia and increase risk for digoxin toxicity.Serious - Use Alternative (2)omeprazole will increase the level or effect of digoxin by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  sodium bicarbonate will increase the level or effect of digoxin by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• doxycycline

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of doxycycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• dronedarone

  Minor (1)dronedarone will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• duloxetine

  Serious - Use Alternative (1)omeprazole will decrease the level or effect of duloxetine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.

• efavirenz

  Monitor Closely (2)efavirenz will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  efavirenz will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• elagolix

  Monitor Closely (2)elagolix will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak inhibitor of CYP2C19. No dose adjustments are needed for omeprazole with 40 mg/day or less. Consider omeprazole dose reduction with higher omeprazole doses (eg, dose for Zollinger-Ellison) if coadministered with elagolix.
  
  elagolix decreases levels of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• eltrombopag

  Monitor Closely (1)omeprazole will decrease the level or effect of eltrombopag by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)sodium bicarbonate decreases levels of eltrombopag by inhibition of GI absorption. Applies only to oral form of both agents. Contraindicated. Separate by at least 4 hours.

• eluxadoline

  Monitor Closely (1)omeprazole increases levels of eluxadoline by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. As a precautionary measure due to incomplete information on the metabolism of eluxadoline, use caution when coadministered with strong CYP2C19 inhibitors.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  Minor (1)elvitegravir/cobicistat/emtricitabine/tenofovir DF, omeprazole. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. Based on drug interaction studies conducted with the components of Stribild, no clinically significant drug interactions have been either observed or are expected when coadministered with PPIs.

• enalapril

  Monitor Closely (1)sodium bicarbonate decreases effects of enalapril by unspecified interaction mechanism. Use Caution/Monitor.

• encorafenib

  Monitor Closely (1)encorafenib, omeprazole. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

• enzalutamide

  Serious - Use Alternative (1)enzalutamide will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ephedrine

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of ephedrine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• erdafitinib

  Serious - Use Alternative (1)omeprazole will increase the level or effect of erdafitinib by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. If coadministration of a strong CYP2C9 inhibitors is unavoidable, closely monitor adverse reactions and modify dose of erdafitinib accordingly. If strong CYP2C9 inhibitor is discontinued, consider increasing erdafitinib dose in the absence of any drug-related toxicities.

• erlotinib

  Contraindicated (1)omeprazole decreases levels of erlotinib by Other (see comment). Contraindicated. Comment: Concomitant use of proton pump inhibitors with erlotinib should be avoided if possible. Drugs that alter pH of upper GI tract may alter the solubility of erlotinib and reduce its bioavailability. .

• erythromycin base

  Monitor Closely (1)sodium bicarbonate increases levels of erythromycin base by unknown mechanism. Use Caution/Monitor.

• erythromycin ethylsuccinate

  Monitor Closely (1)sodium bicarbonate increases levels of erythromycin ethylsuccinate by unknown mechanism. Use Caution/Monitor.

• erythromycin lactobionate

  Monitor Closely (1)sodium bicarbonate increases levels of erythromycin lactobionate by unknown mechanism. Use Caution/Monitor.

• erythromycin stearate

  Monitor Closely (1)sodium bicarbonate increases levels of erythromycin stearate by unknown mechanism. Use Caution/Monitor.

• escitalopram

  Monitor Closely (1)omeprazole will increase the level or effect of escitalopram by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• eslicarbazepine acetate

  Monitor Closely (1)eslicarbazepine acetate will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.Minor (1)eslicarbazepine acetate decreases effects of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. Monitor for GI symptoms; net increased or decreased effect on PPI action unclear due to opposing CYP450 actions.

• esmolol

  Monitor Closely (1)sodium bicarbonate decreases levels of esmolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• estazolam

  Minor (1)omeprazole increases levels of estazolam by decreasing metabolism. Minor/Significance Unknown.

• etidronate

  Monitor Closely (1)sodium bicarbonate decreases levels of etidronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• etravirine

  Monitor Closely (1)etravirine will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.Minor (2)omeprazole will increase the level or effect of etravirine by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.
  
  omeprazole will increase the level or effect of etravirine by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• fedratinib

  Monitor Closely (1)fedratinib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.Serious - Use Alternative (1)omeprazole will increase the level or effect of fedratinib by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of fedratinib (a CYP3A4 and CYP2C19 substrate) with dual CYP3A4 and CYP2C19 inhibitor. Effect of coadministration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib has not been studied.

• ferric carboxymaltose

  Minor (1)omeprazole will decrease the level or effect of ferric carboxymaltose by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown.

• ferric gluconate

  Monitor Closely (1)omeprazole will decrease the level or effect of ferric gluconate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ferric maltol

  Monitor Closely (2)sodium bicarbonate will decrease the level or effect of ferric maltol by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  omeprazole will decrease the level or effect of ferric maltol by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ferrous fumarate

  Monitor Closely (2)omeprazole will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of ferrous fumarate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ferrous gluconate

  Monitor Closely (2)omeprazole will decrease the level or effect of ferrous gluconate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of ferrous gluconate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ferrous sulfate

  Monitor Closely (2)omeprazole will decrease the level or effect of ferrous sulfate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of ferrous sulfate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• fexinidazole

  Monitor Closely (1)fexinidazole will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)fexinidazole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

• fezolinetant

  Contraindicated (1)omeprazole will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors

• finerenone

  Monitor Closely (1)omeprazole will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or weak CYP3A4 inhibitors. Adjust finererone dosage as needed.

• flecainide

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of flecainide by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• fleroxacin

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of fleroxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• flibanserin

  Monitor Closely (2)omeprazole will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.
  
  omeprazole will increase the level or effect of flibanserin by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Coadministration of flibanserin with strong CYP2C19 inhibitors may increase flibanserin exposure and increase the risk of hypotension, syncope, and CNS depression.

• fluconazole

  Monitor Closely (1)fluconazole will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• fluoxetine

  Minor (1)fluoxetine will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• flurazepam

  Minor (1)omeprazole increases levels of flurazepam by decreasing metabolism. Minor/Significance Unknown.

• fluvastatin

  Minor (1)omeprazole will increase the level or effect of fluvastatin by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• fluvoxamine

  Serious - Use Alternative (1)fluvoxamine will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.

• fosamprenavir

  Monitor Closely (2)omeprazole will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of fosamprenavir by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• fosinopril

  Monitor Closely (1)sodium bicarbonate decreases effects of fosinopril by unspecified interaction mechanism. Use Caution/Monitor.

• fosphenytoin

  Monitor Closely (2)omeprazole will increase the level or effect of fosphenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  fosphenytoin will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• gabapentin

  Monitor Closely (1)sodium bicarbonate decreases levels of gabapentin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• gabapentin enacarbil

  Monitor Closely (1)sodium bicarbonate decreases levels of gabapentin enacarbil by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• gefitinib

  Monitor Closely (1)omeprazole decreases levels of gefitinib by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Avoid coadministration of gefitinib with PPIs if possible. If treatment with a PPI is required, separate gefitinib and PPI doses by 12 hr.

• gemifloxacin

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of gemifloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• glipizide

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of glipizide by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.Minor (1)omeprazole will increase the level or effect of glipizide by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• glyburide

  Monitor Closely (2)omeprazole will increase the level or effect of glyburide by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  sodium bicarbonate will increase the level or effect of glyburide by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ibandronate

  Monitor Closely (1)sodium bicarbonate decreases levels of ibandronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• ibuprofen IV

  Minor (1)omeprazole will increase the level or effect of ibuprofen IV by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• idelalisib

  Serious - Use Alternative (1)idelalisib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

• iloperidone

  Monitor Closely (1)iloperidone increases levels of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

• imidapril

  Monitor Closely (1)sodium bicarbonate decreases effects of imidapril by unspecified interaction mechanism. Use Caution/Monitor.

• imipramine

  Monitor Closely (1)omeprazole will increase the level or effect of imipramine by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• indinavir

  Serious - Use Alternative (2)omeprazole will decrease the level or effect of indinavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  sodium bicarbonate will decrease the level or effect of indinavir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• infigratinib

  Serious - Use Alternative (1)omeprazole will decrease the level or effect of infigratinib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• iron dextran complex

  Monitor Closely (2)omeprazole will decrease the level or effect of iron dextran complex by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of iron dextran complex by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• iron sucrose

  Monitor Closely (2)omeprazole will decrease the level or effect of iron sucrose by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of iron sucrose by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• isavuconazonium sulfate

  Monitor Closely (1)omeprazole will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isoniazid

  Monitor Closely (1)sodium bicarbonate decreases levels of isoniazid by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.Serious - Use Alternative (1)isoniazid will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug.

• istradefylline

  Monitor Closely (1)istradefylline will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

• itraconazole

  Monitor Closely (1)sodium bicarbonate decreases levels of itraconazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.Serious - Use Alternative (2)omeprazole will decrease the level or effect of itraconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  sodium bicarbonate will decrease the level or effect of itraconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• ivosidenib

  Serious - Use Alternative (1)ivosidenib will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

• ketoconazole

  Monitor Closely (1)sodium bicarbonate decreases levels of ketoconazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.Serious - Use Alternative (2)omeprazole will decrease the level or effect of ketoconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  sodium bicarbonate will decrease the level or effect of ketoconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• labetalol

  Monitor Closely (1)sodium bicarbonate decreases levels of labetalol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• lactulose

  Monitor Closely (1)sodium bicarbonate decreases effects of lactulose by pharmacodynamic antagonism. Use Caution/Monitor.

• larotrectinib

  Minor (1)larotrectinib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ledipasvir/sofosbuvir

  Monitor Closely (1)omeprazole decreases levels of ledipasvir/sofosbuvir by Other (see comment). Use Caution/Monitor. Comment: Ledipasvir solubility decreases as pH increases; drugs that increase gastric pH are expected to decrease levels of ledipasvir; proton-pump inhibitor doses comparable to omeprazole <20 mg can be administered simultaneously with ledipasvir/sofosbuvir under fasted conditions.

• lemborexant

  Monitor Closely (1)omeprazole will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.

• letermovir

  Monitor Closely (1)letermovir increases levels of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor and dose adjustment may be necessary.

• levofloxacin

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of levofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• levoketoconazole

  Monitor Closely (1)sodium bicarbonate decreases levels of levoketoconazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.Serious - Use Alternative (2)omeprazole will decrease the level or effect of levoketoconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  sodium bicarbonate will decrease the level or effect of levoketoconazole by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.Minor (1)levoketoconazole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• levothyroxine

  Minor (1)omeprazole decreases levels of levothyroxine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.

• lidocaine

  Minor (1)omeprazole will decrease the level or effect of lidocaine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• liothyronine

  Minor (1)omeprazole decreases levels of liothyronine by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.

• liotrix

  Minor (1)omeprazole decreases levels of liotrix by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.

• lisdexamfetamine

  Minor (1)omeprazole, lisdexamfetamine. Other (see comment). Minor/Significance Unknown. Comment: Reduced gastric acidity caused by proton pump inhibitors decreases time to Tmax for amphetamine and dextroamphetamine. AUC was unaffected. .

• lisinopril

  Monitor Closely (1)sodium bicarbonate decreases effects of lisinopril by unspecified interaction mechanism. Use Caution/Monitor.

• lomitapide

  Monitor Closely (1)omeprazole increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.

• lonafarnib

  Serious - Use Alternative (2)omeprazole will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.
  
  lonafarnib will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Avoid or Use Alternate Drug. Lonafarnib may increase the AUC and peak concentration of CYP2C19 substrates. If coadministration unavoidable, monitor for adverse reactions and reduce the CYP2C19 substrate dose in accordance with its approved product labeling.

• lorazepam

  Minor (1)omeprazole increases levels of lorazepam by decreasing metabolism. Minor/Significance Unknown.

• losartan

  Monitor Closely (1)omeprazole will increase the level or effect of losartan by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor. May inhibit the conversion of losartan to its active metabolite E-3174. Importance of interaction not established; monitor individual therapeutic response to determine losartan dosage.

• lumacaftor/ivacaftor

  Monitor Closely (2)lumacaftor/ivacaftor will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lumacaftor/ivacaftor is a strong CYP3A4 inhibitor and also has the potential to induce CYP2C19 and both induce and inhibitor P-gp.
  
  lumacaftor/ivacaftor, omeprazole. affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. In vitro studies suggest that lumacaftor may induce and ivacaftor may inhibit CYP2C19 substrates. .

• mavacamten

  Contraindicated (1)omeprazole will increase the level or effect of mavacamten by affecting hepatic enzyme CYP2C19 metabolism. Contraindicated. Strong or moderate CYP2C19 inhibitors may increase mavacamten systemic exposure, resulting in heart failure due to systolic dysfunction.

• memantine

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of memantine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.

• mesalamine

  Serious - Use Alternative (1)omeprazole decreases effects of mesalamine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Applies only to sustained release dosage form.Minor (1)sodium bicarbonate, mesalamine. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• methamphetamine

  Minor (1)omeprazole decreases levels of methamphetamine by Other (see comment). Minor/Significance Unknown. Comment: Time to maximum concentration (Tmax) of amphetamine is decreased compared to when administered alone; monitor patients for changes in clinical effect and adjust therapy based on clinical response.

• methotrexate

  Monitor Closely (1)omeprazole increases levels of methotrexate by decreasing renal clearance. Use Caution/Monitor. Temporary withdrawal of PPI may be considered in some patients.

• methscopolamine

  Monitor Closely (1)sodium bicarbonate decreases levels of methscopolamine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

• methylphenidate

  Monitor Closely (1)omeprazole decreases effects of methylphenidate by enhancing GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Since the characteristics of methylphenidate extended release capsules (Ritalin LA) are pH dependent, coadministration of antacids or acid suppressants could alter the release of methylphenidate. Consider separating the administration of the antacid and the methylphenidate extended-release capsules may be avoided.

• metoprolol

  Monitor Closely (1)sodium bicarbonate decreases levels of metoprolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• mexiletine

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of mexiletine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.Minor (1)omeprazole will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• midazolam

  Minor (1)omeprazole increases levels of midazolam by decreasing metabolism. Minor/Significance Unknown.

• midazolam intranasal

  Monitor Closely (1)omeprazole will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.

• minocycline

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of minocycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• mitotane

  Minor (1)mitotane decreases levels of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

• modafinil

  Monitor Closely (1)modafinil will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• moexipril

  Monitor Closely (1)sodium bicarbonate decreases effects of moexipril by unspecified interaction mechanism. Use Caution/Monitor.

• moxifloxacin

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of moxifloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• mycophenolate

  Monitor Closely (2)omeprazole will decrease the level or effect of mycophenolate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor. Potential interaction applies to mycophenolate mofetil. Enteric coated mycophenolate sodium formulation is less sensitive to this interaction. Clinical significance unclear.
  
  sodium bicarbonate will decrease the level or effect of mycophenolate by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• nadolol

  Monitor Closely (1)sodium bicarbonate decreases levels of nadolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• nateglinide

  Monitor Closely (1)omeprazole will increase the level or effect of nateglinide by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• nebivolol

  Monitor Closely (1)sodium bicarbonate decreases levels of nebivolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• nelfinavir

  Contraindicated (1)omeprazole decreases levels of nelfinavir by unspecified interaction mechanism. Contraindicated. Coadministration may lead to loss of nelfinavir virologic response and development of resistance; mechanism may be CYP2C19 inhibition of nelfinavir conversion to active M8 metabolite, and also PPIs decreasing gastric pH resulting in decreased nelfinavir absorption.

• neratinib

  Serious - Use Alternative (1)omeprazole will decrease the level or effect of neratinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• nilotinib

  Serious - Use Alternative (1)omeprazole will decrease the level or effect of nilotinib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Nilotinib has a pH-dependent solubility and solubility is decreased at higher pH; separating doses may not eliminate this effect because of PPI extended duration of action

• nimodipine

  Serious - Use Alternative (1)sodium bicarbonate will increase the level or effect of nimodipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• nisoldipine

  Serious - Use Alternative (2)sodium bicarbonate will increase the level or effect of nisoldipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.
  
  omeprazole will increase the level or effect of nisoldipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• nitrendipine

  Serious - Use Alternative (1)sodium bicarbonate will increase the level or effect of nitrendipine by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug.

• nitrofurantoin

  Monitor Closely (1)sodium bicarbonate decreases levels of nitrofurantoin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• ofloxacin

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of ofloxacin by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• olanzapine

  Minor (1)omeprazole will decrease the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• omadacycline

  Monitor Closely (1)sodium bicarbonate will decrease the level or effect of omadacycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.

• ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)

  Monitor Closely (1)ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) will decrease the level or effect of omeprazole by unspecified interaction mechanism. Use Caution/Monitor. Monitor for decreased omeprazole efficacy; consider increasing omeprazole dose in patients whose symptoms are not well controlled (not to exceed 40 mg/day)

• ospemifene

  Minor (1)omeprazole increases levels of ospemifene by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• oxcarbazepine

  Monitor Closely (1)oxcarbazepine will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• oxytetracycline

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of oxytetracycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• pamidronate

  Monitor Closely (1)sodium bicarbonate decreases levels of pamidronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• pazopanib

  Serious - Use Alternative (1)omeprazole will decrease the level or effect of pazopanib by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with drugs that raise gastric pH; consider short-acting antacids in place of PPIs and H2 antagonists; separate antacid and pazopanib dosing by several hours

• penbutolol

  Monitor Closely (1)sodium bicarbonate decreases levels of penbutolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• penicillamine

  Monitor Closely (1)sodium bicarbonate decreases levels of penicillamine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• pentobarbital

  Monitor Closely (1)pentobarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• perindopril

  Monitor Closely (1)sodium bicarbonate decreases effects of perindopril by unspecified interaction mechanism. Use Caution/Monitor.

• pexidartinib

  Serious - Use Alternative (1)omeprazole will decrease the level or effect of pexidartinib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Avoid coadministration of proton pump inhibitors (PPIs) with pexidartinib. Use H2-receptor antagonists or antacids if needed. When using alternatives to PPIs, administer pexidartinib 2 hr before or after taking locally-acting antacids OR administer pexidartinib at least 2 hr before or 10 hr after taking an H2-receptor antagonist.

• phenobarbital

  Monitor Closely (1)phenobarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)phenobarbital will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• phenytoin

  Monitor Closely (2)omeprazole will increase the level or effect of phenytoin by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.
  
  phenytoin will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• phytoestrogens

  Minor (1)omeprazole decreases levels of phytoestrogens by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• pindolol

  Monitor Closely (1)sodium bicarbonate decreases levels of pindolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• polysaccharide iron

  Monitor Closely (2)omeprazole will decrease the level or effect of polysaccharide iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of polysaccharide iron by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• ponatinib

  Minor (1)omeprazole decreases levels of ponatinib by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown.

• posaconazole

  Monitor Closely (3)omeprazole will decrease the level or effect of posaconazole by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  posaconazole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of posaconazole by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• primidone

  Monitor Closely (2)primidone will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  primidone will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• propranolol

  Monitor Closely (1)sodium bicarbonate decreases levels of propranolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• pseudoephedrine

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of pseudoephedrine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor. Caution advised with frequent or high dose antacids

• quazepam

  Minor (1)omeprazole increases levels of quazepam by decreasing metabolism. Minor/Significance Unknown.

• quinapril

  Monitor Closely (1)sodium bicarbonate decreases effects of quinapril by unspecified interaction mechanism. Use Caution/Monitor.

• quinidine

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of quinidine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor. Elevated quinidine plasma levels, possibly with cardiac conduction disturbances and arrhythmias, may occur.

• ramipril

  Monitor Closely (1)sodium bicarbonate decreases effects of ramipril by unspecified interaction mechanism. Use Caution/Monitor.

• ribociclib

  Minor (1)ribociclib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• rifampin

  Monitor Closely (2)rifampin will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of rifampin by Other (see comment). Use Caution/Monitor. Concomitant antacid administration may reduce absorption of rifampin; daily doses of rifampin should be given at least 1 hr before ingestion of antacidsSerious - Use Alternative (1)rifampin will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifapentine

  Serious - Use Alternative (1)rifapentine will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rilpivirine

  Contraindicated (1)omeprazole decreases levels of rilpivirine by increasing gastric pH. Applies only to oral form of both agents. Contraindicated. Concurrent use may cause treatment failure and/or the development of rilpivirine or NNRTI resistance owing to decreased levels.

• riluzole

  Minor (1)omeprazole will decrease the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• riociguat

  Monitor Closely (2)sodium bicarbonate decreases levels of riociguat by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate administration by at least 1 hour.
  
  omeprazole will decrease the level or effect of riociguat by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• risedronate

  Monitor Closely (1)sodium bicarbonate decreases levels of risedronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• ritonavir

  Monitor Closely (1)ritonavir will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• roflumilast

  Monitor Closely (1)omeprazole will decrease the level or effect of roflumilast by affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Concomitant therapy may reduce therapeutic effectiveness.

• rose hips

  Monitor Closely (2)omeprazole will decrease the level or effect of rose hips by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.
  
  sodium bicarbonate will decrease the level or effect of rose hips by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.

• rosuvastatin

  Monitor Closely (1)sodium bicarbonate decreases levels of rosuvastatin by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• ruxolitinib

  Minor (1)omeprazole will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ruxolitinib topical

  Minor (1)omeprazole will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• salicylates (non-asa)

  Minor (1)sodium bicarbonate, salicylates (non-asa). Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• salsalate

  Minor (1)sodium bicarbonate, salsalate. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• sarecycline

  Monitor Closely (1)sodium bicarbonate will decrease the level or effect of sarecycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.

• secobarbital

  Monitor Closely (1)secobarbital will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)secobarbital will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• secretin

  Serious - Use Alternative (1)omeprazole, secretin. Other (see comment). Avoid or Use Alternate Drug. Comment: Concomitant use of PPIs may cause a hyperresponse in gastrin secretion in response to stimulation testing with secretin, falsely suggesting gastrinoma. The time it takes for serum gastrin concentrations to return to baseline following discontinuation of PPIs is specific to the individual PPI. Temporarily stop omeprazole treatment at least 14 days before assessing to allow gastrin levels to return to baseline.

• siponimod

  Serious - Use Alternative (1)omeprazole will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.

• sodium sulfate/potassium chloride/magnesium sulfate/polyethylene glycol

  Monitor Closely (1)sodium bicarbonate and sodium sulfate/potassium chloride/magnesium sulfate/polyethylene glycol both decrease serum potassium. Modify Therapy/Monitor Closely.

• sofosbuvir/velpatasvir

  Serious - Use Alternative (1)omeprazole will decrease the level or effect of sofosbuvir/velpatasvir by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Velpatasvir solubility decreases as gastric pH increases (practically insoluble at pH >5). Coadministration of sofosbuvir/velpatasvir with omeprazole or other PPIs is not recommended. If considered medically necessary, give sofosbuvir/velpatasvir with food 4 hr before omeprazole 20 mg. Use with other PPIs has not been studied.

• sotalol

  Monitor Closely (1)sodium bicarbonate decreases levels of sotalol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• sotorasib

  Serious - Use Alternative (1)omeprazole will decrease the level or effect of sotorasib by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. If use with an acid-reducing agent cannot be avoided, administer sotorasib 4 hr before or 10 hr after administration of a locally-acting antacid.

• sparsentan

  Monitor Closely (1)sparsentan will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Sparsentan (a CYP2C19 inducer) decreases exposure of CYP2C19 substrates and reduces efficacy related to these substrates. Serious - Use Alternative (1)omeprazole decreases effects of sparsentan by increasing gastric pH. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Proton pump inhibitors may decrease sparsentan exposure which may reduce efficacy of sparsentan.

• St John's Wort

  Monitor Closely (1)St John's Wort will decrease the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• stiripentol

  Monitor Closely (2)stiripentol, omeprazole. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
  
  stiripentol will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Consider reducing the dose of CYP2C19 substrates, if adverse reactions are experienced when administered concomitantly with stiripentol.

• strontium ranelate

  Minor (1)sodium bicarbonate decreases levels of strontium ranelate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. Separate by 2 hr when possible.

• sulfamethoxazole

  Minor (1)omeprazole will increase the level or effect of sulfamethoxazole by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• sulfasalazine

  Minor (1)sodium bicarbonate, sulfasalazine. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• tacrolimus

  Monitor Closely (1)omeprazole will increase the level or effect of tacrolimus by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. Concomitant administration may increase tacrolimus whole blood concentrations, particularly in intermediate or poor metabolizers of CYP2C19

• tamoxifen

  Monitor Closely (1)omeprazole will increase the level or effect of tamoxifen by affecting hepatic enzyme CYP2C9/10 metabolism. Use Caution/Monitor.

• tazemetostat

  Monitor Closely (2)tazemetostat will decrease the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  omeprazole will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tetracycline

  Serious - Use Alternative (1)sodium bicarbonate decreases levels of tetracycline by inhibition of GI absorption. Applies only to oral form of both agents. Avoid or Use Alternate Drug. Separate by 2 hours.

• theophylline

  Minor (2)omeprazole will decrease the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
  
  omeprazole increases toxicity of theophylline by Other (see comment). Minor/Significance Unknown. Comment: Prolonged use of proton pump inhibitors can cause hypochlorhydria, which in turn causes peristalsis in small intestine to increase and peristalsis in the proximal colon to decrease; monitor for toxicity.

• thyroid desiccated

  Minor (1)omeprazole decreases levels of thyroid desiccated by increasing gastric pH. Applies only to oral form of both agents. Minor/Significance Unknown. Conflicting evidence regarding this interaction exists.

• tiludronate

  Monitor Closely (1)sodium bicarbonate decreases levels of tiludronate by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• timolol

  Monitor Closely (1)sodium bicarbonate decreases levels of timolol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.

• tinidazole

  Monitor Closely (1)omeprazole will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tizanidine

  Minor (1)omeprazole will decrease the level or effect of tizanidine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.

• tofacitinib

  Monitor Closely (1)omeprazole increases levels of tofacitinib by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor. No specific dose adjustment recommended when tofacitinib coadministered with potent CYP2C19 inhibitors; decrease tofacitinib dose if coadministered with both moderate CYP3A4 and potent CYP2C19 inhibitors .

• tolbutamide

  Monitor Closely (1)sodium bicarbonate will increase the level or effect of tolbutamide by increasing gastric pH. Applies only to oral form of both agents. Use Caution/Monitor.Minor (1)omeprazole will increase the level or effect of tolbutamide by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.

• trandolapril

  Monitor Closely (1)sodium bicarbonate decreases effects of trandolapril by unspecified interaction mechanism. Use Caution/Monitor.

• triazolam

  Minor (1)omeprazole increases levels of triazolam by decreasing metabolism. Minor/Significance Unknown.

• triclabendazole

  Monitor Closely (1)triclabendazole will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.

• tucatinib

  Serious - Use Alternative (1)tucatinib will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

• ursodiol

  Monitor Closely (1)sodium bicarbonate decreases effects of ursodiol by pharmacodynamic antagonism. Use Caution/Monitor.

• vismodegib

  Monitor Closely (1)omeprazole will decrease the level or effect of vismodegib by Other (see comment). Use Caution/Monitor. Drugs that increase gastric pH alter vismodegib solubility and therefore reduce bioavailability; effect on efficacy unknown

• voriconazole

  Monitor Closely (2)voriconazole will increase the level or effect of omeprazole by affecting hepatic enzyme CYP2C19 metabolism. Use Caution/Monitor.
  
  voriconazole will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)omeprazole will increase the level or effect of voriconazole by affecting hepatic enzyme CYP2C19 metabolism. Minor/Significance Unknown.

• voxelotor

  Serious - Use Alternative (1)voxelotor will increase the level or effect of omeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

• warfarin

  Monitor Closely (1)omeprazole will increase the level or effect of warfarin by Other (see comment). Use Caution/Monitor. Warfarin's less potent R-enantiomer is metabolized in part by CYP3A4 (and also CYP1A2 and CYP2C19). Monitor INR more frequently if coadministered with inhibitors of these isoenzymes and adjust warfarin dose if needed.

• willow bark

  Minor (1)sodium bicarbonate, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• zoledronic acid

  Monitor Closely (1)sodium bicarbonate decreases levels of zoledronic acid by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Separate by 2 hours.