loperamide/simethicone (OTC)

Brand and Other Names:Imodium Multi-Symptom Relief

Dosing & Uses

AdultPediatricGeriatric

Diarrhea/Flatulence

After each loose bowel movement: 2 tablets once initially, then 1 tab/dose with each subsequent loose stool up to 4 tab/day

Diarrhea/Flatulence

<6 years: Safety and efficacy not established

6-8 years: 1 tablet once initially, then one-half tablet/dose, up to 2 tablets/day

9-12 years: 1 tablet once initially, then one-half tablet/dose, up to 3 tablets/day

≥ 12 years: After each loose bowel movement: 2 tablets once initially, then 1 tab/dose with each subsequent loose stool up to 4 tab/day

Diarrhea/Flatulence

After each loose bowel movement: 2 tablets once initially, then 1 tab/dose with each subsequent loose stool up to 4 tab/day

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Interactions

Interaction Checker

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              Serious - Use Alternative (38)

              • amisulpride

                amisulpride and loperamide both increase QTc interval. Avoid or Use Alternate Drug. ECG monitoring is recommended if coadministered.

              • anagrelide

                anagrelide and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • artemether

                artemether and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • artemether/lumefantrine

                artemether/lumefantrine and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • asenapine

                asenapine and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • asenapine transdermal

                asenapine transdermal and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • bedaquiline

                bedaquiline and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • buprenorphine

                buprenorphine and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • buprenorphine buccal

                buprenorphine buccal and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • buprenorphine subdermal implant

                buprenorphine subdermal implant and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • buprenorphine transdermal

                buprenorphine transdermal and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • buprenorphine, long-acting injection

                buprenorphine, long-acting injection and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • ceritinib

                ceritinib and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • chloroquine

                chloroquine and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • citalopram

                citalopram and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • clarithromycin

                clarithromycin and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • clozapine

                clozapine and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • crizotinib

                crizotinib and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • desflurane

                desflurane and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • eluxadoline

                loperamide, eluxadoline. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that cause constipation. Increases risk for constipation related serious adverse reactions. Loperamide may be used occasionally for acute management of severe diarrhea but avoid chronic use. Discontinue loperamide immediately if constipation occurs.

              • entrectinib

                entrectinib and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • erdafitinib

                erdafitinib will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If coadministration unavoidable, separate administration by at least 6 hr before or after administration of P-gp substrates with narrow therapeutic index.

              • eribulin

                eribulin and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • fentanyl

                fentanyl, loperamide. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

              • fentanyl intranasal

                fentanyl intranasal, loperamide. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

              • fentanyl transdermal

                fentanyl transdermal, loperamide. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

              • fentanyl transmucosal

                fentanyl transmucosal, loperamide. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

              • fexinidazole

                fexinidazole and loperamide both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels or prolong QT interval.

                fexinidazole will increase the level or effect of loperamide 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.

              • infigratinib

                simethicone 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. If use with an acid-reducing agent cannot be avoided, administer infigratinib 2 hr before and after administration of a locally-acting antacid.

              • isoflurane

                isoflurane and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • lasmiditan

                lasmiditan increases levels of loperamide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

              • lefamulin

                lefamulin and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • oxaliplatin

                oxaliplatin and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • quinidine

                quinidine will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.

              • sevoflurane

                sevoflurane and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              • sotorasib

                sotorasib will decrease the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If use is unavoidable, refer to the prescribing information of the P-gp substrate for dosage modifications.

                simethicone 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.

              • tepotinib

                tepotinib will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If concomitant use unavoidable, reduce the P-gp substrate dosage if recommended in its approved product labeling.

              • tetrabenazine

                tetrabenazine and loperamide both increase QTc interval. Avoid or Use Alternate Drug.

              Monitor Closely (60)

              • albuterol

                albuterol and loperamide both increase QTc interval. Use Caution/Monitor.

              • alfuzosin

                alfuzosin and loperamide both increase QTc interval. Use Caution/Monitor.

              • amiodarone

                amiodarone will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • apomorphine

                apomorphine and loperamide both increase QTc interval. Use Caution/Monitor.

              • arformoterol

                arformoterol and loperamide both increase QTc interval. Use Caution/Monitor.

              • aripiprazole

                aripiprazole and loperamide both increase QTc interval. Use Caution/Monitor.

              • atomoxetine

                atomoxetine and loperamide both increase QTc interval. Use Caution/Monitor.

              • atorvastatin

                atorvastatin will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • berotralstat

                berotralstat will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor or titrate P-gp substrate dose if coadministered.

              • bosutinib

                bosutinib increases levels of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • clarithromycin

                clarithromycin will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • clotrimazole

                clotrimazole will decrease the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • crizotinib

                crizotinib increases levels of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • cyclosporine

                cyclosporine will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • dasatinib

                dasatinib and loperamide both increase QTc interval. Use Caution/Monitor.

              • degarelix

                degarelix and loperamide both increase QTc interval. Use Caution/Monitor.

              • deutetrabenazine

                deutetrabenazine and loperamide both increase QTc interval. Use Caution/Monitor. At the maximum recommended dose, deutetrabenazine does not prolong QT interval to a clinically relevant extent. Certain circumstances may increase risk of torsade de pointes and/or sudden death in association with drugs that prolong the QTc interval (eg, bradycardia, hypokalemia or hypomagnesemia, coadministration with other drugs that prolong QTc interval, presence of congenital QT prolongation).

              • dolasetron

                dolasetron and loperamide both increase QTc interval. Use Caution/Monitor.

              • donepezil

                donepezil and loperamide both increase QTc interval. Use Caution/Monitor.

              • doxepin

                doxepin and loperamide both increase QTc interval. Use Caution/Monitor.

              • dronedarone

                dronedarone will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • efavirenz

                efavirenz and loperamide both increase QTc interval. Use Caution/Monitor.

              • elagolix

                elagolix will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • eliglustat

                eliglustat increases levels of loperamide by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.

                eliglustat and loperamide both increase QTc interval. Use Caution/Monitor.

              • erythromycin base

                erythromycin base will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • erythromycin ethylsuccinate

                erythromycin ethylsuccinate will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • erythromycin lactobionate

                erythromycin lactobionate will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • erythromycin stearate

                erythromycin stearate will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • felodipine

                felodipine will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • fosphenytoin

                fosphenytoin will decrease the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • fostamatinib

                fostamatinib will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Concomitant use of fostamatinib may increase concentrations of P-gp substrates. Monitor for toxicities of the P-gp substrate drug that may require dosage reduction when given concurrently with fostamatinib.

              • fostemsavir

                loperamide and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

              • gemifloxacin

                gemifloxacin and loperamide both increase QTc interval. Use Caution/Monitor.

              • gilteritinib

                gilteritinib and loperamide both increase QTc interval. Use Caution/Monitor.

              • glecaprevir/pibrentasvir

                glecaprevir/pibrentasvir will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • granisetron

                granisetron and loperamide both increase QTc interval. Use Caution/Monitor.

              • hydroxyzine

                hydroxyzine and loperamide both increase QTc interval. Use Caution/Monitor.

              • indinavir

                indinavir will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • istradefylline

                istradefylline will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.

              • itraconazole

                itraconazole and loperamide both increase QTc interval. Use Caution/Monitor.

              • ivacaftor

                ivacaftor increases levels of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.

              • ketoconazole

                ketoconazole will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • lapatinib

                lapatinib will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • lenacapavir

                lenacapavir will increase the level or effect of loperamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.

              • levoketoconazole

                levoketoconazole will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • lithium

                lithium and loperamide both increase QTc interval. Use Caution/Monitor.

              • lomitapide

                lomitapide increases levels of loperamide by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing dose when used concomitantly with lomitapide.

              • lonafarnib

                lonafarnib will increase the level or effect of loperamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Loperamide is contraindicated in patients aged <2 years; when lonafarnib is coadministered with loperamide, do not exceed loperamide 1 mg qDay when first coadministered; slowly increase loperamide dosage with caution in accordance with its approved product labeling.

                lonafarnib will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Lonafarnib is a weak P-gp inhibitor. Monitor for adverse reactions if coadministered with P-gp substrates where minimal concentration changes may lead to serious or life-threatening toxicities. Reduce P-gp substrate dose if needed.

              • loratadine

                loratadine will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • lovastatin

                lovastatin will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • metoclopramide intranasal

                loperamide will decrease the level or effect of metoclopramide intranasal by Other (see comment). Use Caution/Monitor. Coadministration of metoclopramide intranasal with drugs that impair GI motility may decrease systemic absorption of metoclopramide. Monitor for reduced therapeutic effect.

              • mirtazapine

                mirtazapine and loperamide both increase QTc interval. Use Caution/Monitor.

              • nefazodone

                nefazodone will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • nicardipine

                nicardipine will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • nifedipine

                nifedipine will decrease the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • nilotinib

                nilotinib will increase the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              • olanzapine

                olanzapine and loperamide both increase QTc interval. Use Caution/Monitor.

              • osilodrostat

                osilodrostat and loperamide both increase QTc interval. Use Caution/Monitor.

              • pexidartinib

                simethicone will decrease the level or effect of pexidartinib by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Separate pexidartinib by 2 hr before or after taking a locally-acting antacid.

              • phenobarbital

                phenobarbital will decrease the level or effect of loperamide by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.

              Minor (2)

              • gemfibrozil

                gemfibrozil will increase the level or effect of loperamide by decreasing metabolism. Minor/Significance Unknown.

              • itraconazole

                itraconazole will increase the level or effect of loperamide by Other (see comment). Minor/Significance Unknown. Monitor ECG when itraconazole is coadministered with loperamide (dose >16mg/day).

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              Adverse Effects

              Frequency Not Defined

              Dizziness

              Fatigue

              Headache

              Abdominal pain

              Dry mouth

              Nausea

              Diarrhea

              Vomiting

              Pancreatitis

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              Warnings

              Contraindications

              Hypersensitivity, bloody diarrhea, high fever, infectious diarrhea, pseudomembranous colitis

              Patients in whom constipation must be avoided

              Abdominal pain without diarrhea

              Avoid use as primary therapy with acute dysentery (bloody stools and high fever, acute ulcerative colitis, bacterial enterocolitis [caused by Salmonella, Shigella, and Campylobacter), pseudomembranous colitis associated with antibiotic use)

              Age <2 years

              Cautions

              Chewable tab should be chewed thoroughly before swallowing

              loperamide

              • May cause drowsiness or dizziness, which may impair physical abilities to operate heavy machinery or tasks requiring mental alertness
              • Ask healthcare professional if mucus present in stool or history of abnormal heart rhythm
              • Hypersensitivity reactions reported, including anaphylaxis, rash, urticaria, and rare cases of Steven’s Johnson syndrome or toxic epidermal necrolysis
              • Discontinue if no improvement seen within 48 hr in patients with acute diarrhea, symptoms worsen, or abdominal swelling or bulging develops
              • Discontinue promptly if constipation, abdominal pain or distention, blood in stool, or ileus develops; do not use when peristalsis inhibition should be avoided (ie, due to potential for ileus, megacolon, or toxic megacolon)
              • Discontinue therapy if symptoms of abdominal distention occur in patients with AIDS; cases of toxic megacolon reported with infectious colitis, resulting from viral or bacterial pathogens
              • Taking more than directed can cause serious heart problems or death
              • Use with caution in patients with hepatic impairment due to reduced first-pass metabolism; monitor for signs of CNS toxicity
              • Use of higher than recommended doses or abuse of loperamide can result in serious cardiac adverse events, including QT interval prolongation, Torsades de Pointes, or other ventricular arrhythmias, syncope, and cardiac arrest; in cases of abuse, individuals often use other drugs together with loperamide in attempts to increase its absorption and penetration across the blood-brain barrier, inhibit loperamide metabolism, and enhance its euphoric effects

              simethicone

              • Can cause false-negative gastric guaiac test
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              Pregnancy & Lactation

              Pregnancy category: B (loperamide); C (simethicone)

              Lactation: Unknown if distributed in to breast milk, use caution

              Pregnant or breastfeeding patients should seek advice of health professional before using OTC drugs

              Pregnancy Categories

              A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

              B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

              C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

              D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

              X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

              NA: Information not available.

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              Pharmacology

              Mechanism of Action

              Slows intestinal motility by direct effects on circular & longitudinal muscle (loperamide); changes surface tension of gas bubbles, causing collapse of foam bubbles, thus allow easier passage (simethicone)

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              Images

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              Patient Handout

              A Patient Handout is not currently available for this monograph.
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              Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.