ampicillin (Rx)

Brand and Other Names:Ampi, Omnipen, more...Penglobe, Principen
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Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

capsules

  • 250mg
  • 500mg

oral suspension

  • 125mg/5mL
  • 250mg/5mL

powder for injection

  • 125mg
  • 250mg
  • 500mg
  • 1g
  • 2g
  • 10g

General Dosing Guidelines

PO: 250-500 mg q6hr

IV/IM: 1-2 g q4-6hr or 50-250 mg/kg/day divided q4-6hr; not to exceed 12 g/day  

Endocarditis Prophylaxis (Off-label)

Dental, oral, or respiratory tract procedures

  • 2 g or 50 mg/kg IV/IM within 30-60 minutes before procedure in patients not allergic to penicillin and unable to take oral amoxicillin

Genitourinary and gastrointestinal tract procedures

  • Routine prophylaxis for GI/GU procedures no longer recommended by AHA; consider only patients with highest risk of adverse outcome from endocarditis (eg, prosthetic heart valve, previous endocarditis, some categories of congenital heart disease, cardiac valvulopathy in cardiac transplant patients) with established GI or GU enterococcal infection or for those already receiving antibiotic therapy to prevent a wound infection or sepsis associated with GI or GU procedure in which enterococcal coverage is desired
  • High-risk patients: 2 g IV/IM within 30 min prior to procedure, followed by ampicillin 1 g (or amoxicillin 1 g orally) 6 hr later, must be used in combination with gentamicin
  • Moderate-risk patients: 2 g IV/IM within 30 min prior to procedure

Endocarditis (Off-label)

Listeria endocarditis: 200 mg/kg/day IV divided q6hr; administer concomitantly with aminoglycoside for at least 4-6 wk

Genitourinary Tract Infections (Excluding Gonorrhea)

<40 kg: 50 mg/kg/day IV/IM divided q6-8hr

≥40 kg: 500 mg PO/IV/IM q6hr

Gastrointestinal Tract Infections

<40 kg: 50 mg/kg/day IV/IM divided q6-8hr

≥40 kg: 500 mg IV/IM q6hr; larger doses may be necessary in severe or chronic infection

Urinary Tract Infection (ampicillin-susceptible Enterococcus; Off-label)

1-2 g IV q4-6hr with or without an aminoglycoside

Gonorrhea

3.5 g IV administered once simultaneously with 1 g of probenecid

Respiratory Tract Infections

≥40 kg

  • 250 mg PO q6hr
  • 250-500 mg IV/IM q6hr

<40 kg

  • 25 to 50 mg/kg/day IV or IM divided q6-8hr

Bacterial Meningitis/Septicemia

150-200 mg/kg/day IV divided q6-8hr; initiate with IV infusion; may continue with IM injections if preferred; range 6-12 g/day  

Group B Streptococcus (Off-label)

Maternal dose for neonatal prophylaxis

2 g IV initially, followed by 1 g q4hr until delivery

Listeria Infection (Off-label)

2 g IV q4hr

Administration

Take oral dosage form on empty stomach

Dosing Modifications

Renal impairment

  • CrCl <10 mL/min: Administer q12-24hr
  • CrCl 10-50 mL/min: Administer q6-12hr
  • CrCl >50 mL/min: Administer q6hr

Hepatic impairment

  • Not studied

Dosage Forms & Strengths

capsules

  • 250mg
  • 500mg

oral suspension

  • 125mg/5mL
  • 250mg/5mL

powder for injection

  • 125mg
  • 250mg
  • 500mg
  • 1g
  • 2g

General Dosing Guidelines

25-200 mg/kg/day IV/IM divided q6-8hr; not to exceed 12 g/day  

50-100 mg/kg/day PO divided q6hr; not to exceed 2-4 g/day

Severe infection: 200-400 mg/kg/day IV/IM divided q6hr

Potential toxic dose <6 years: 300 mg/kg

Neonates (<28 Days)

<7 days

  • <2 kg: 50-100 mg/kg/day IV/IM divided q12hr  
  • >2 kg: 75-150 mg/kg/day IV/IM divided q8hr

>7 days

  • <1.2 kg: 50-100 mg/kg/day IV/IM divided q12hr
  • 1.2-2 kg: 75-150 mg/kg/day IV/IM divided q8hr
  • >2 kg: 100-200 mg/kg/day IV/IM divided q6hr

Endocarditis Prophylaxis (Off-label)

50 mg/kg IV/IM (+/- gentamicin 1.5 mg/kg for GI/GU) within 30-60 minutes before procedure  

Dosing considerations

  • AHA Guidelines recommend only for high risk patients

Endocarditis Treatment

300 mg/kg/day IV divided q4-6hr in combination with other antibiotics; not to exceed 12 g/day

Genitourinary Tract Infections

<40 kg: 50-100 mg/kg/day IV/IM divided q6hr  

≥40 kg: 500 mg IV/IM q6hr

Gastrointestinal Tract Infections

<20 kg: 50-100 mg/kg/day PO divided q6hr  

>20 kg: 500 mg PO q6hr

<40 kg: 50 mg/kg/day IV/IM divided q6-8hr

>40 kg: 500 mg IV/IM q6hr

Gonorrhea

<20 kg: Safety and efficacy not established

>20 kg: 3.5 g PO administered once simultaneously with 1 g of probenecid

Respiratory Tract Infections

<20 kg: 50 mg/kg/day PO divided q6-8hr  

>20 kg: 250 mg PO q6hr

<40 kg: 25-50 mg/kg/day IV/IM divided q6-8hr

>40 kg: 250-500 mg IV/IM q6hr

Bacterial Meningitis/Septicemia

150-200 mg/kg/day IV/IM divided q3-4hr; should initiate with IV infusion therapy and continued with IM injections if preferred

Soft Tissue Infections

<40 kg: 25-50 mg/kg/day IV/IM divided q6-8hr

≥40 kg: 250-500 mg IV/IM q6hr

Community Acquired Pneumonia

< 3 months: Safety and efficacy not established

> 3 months:

Empiric treatment or S. pneumoniae

  • MICs to penicillin ≤ 2 mcg/mL or H. influenzae (beta-lactamase negative, preferred: 150-200 mg/kg/day IV/IM divided q6hr
  • MICs to penicillin ≥ 4 mg/mL; alternative to ceftriaxone: 300-400 mg/kg/day IV/IM divided q6hr

Group A Streptococcus

  • Moderate to severe (preferred): 200 mg/kg/day IVIM divided q6hr

Administration

Take oral dosage form on empty stomach

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Interactions

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            Adverse Effects

            Frequency Not Defined

            Erythema multiforme

            Exfoliative dermatitis

            Rash

            Urticaria

            Fever

            Seizure

            Black hairy tongue

            Diarrhea

            Enterocolitis

            Glossitis

            Nausea

            Oral candidiasis

            Pseudomembranous colitis

            Stomatitis

            Vomiting

            Agranulocytosis

            Anemia

            Hemolytic anemia

            Eosinophilia

            Leukopenia

            Thrombocytopenia purpura

            Anaphylaxis

            Aspartate aminotransferase increased

            Interstitial nephritis

            Laryngeal stridor

            Serum sickness-like reaction

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            Warnings

            Contraindications

            Hypersensitivity

            Cautions

            Use caution in allergy to cephalosporins, carbapenems

            Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction

            Endocarditis prophylaxis: Use only for high-risk patients, per AHA Guidelines

            Prolonged use associated with fungal or bacterial superinfection

            Rash has developed during therapy in high percentage of patients with infectious mononucleosis receiving ampicillin class antibiotics; avoid therapy in these patients

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            Pregnancy & Lactation

            Pregnancy category: B

            Lactation: Excreted in breast milk; use caution

            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

            Broad-spectrum penicillin; interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms; alternative to amoxicillin when unable to take medication orally

            Absorption

            Peak plasma time: 1-2 hr (oral)

            Bioavailability: 30-40%

            Distribution

            Protein bound: 15-25%

            Blister and tissue fluids, bile, and CSF with inflamed meninges

            Metabolism

            Liver

            Elimination

            Half-life: 1-1.8 hr (normal renal function); 7-20 hr (anuria/end-stage renal disease)

            Excretion: Urine (90% within 24 hr)

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            Administration

            IV Incompatibilities

            Solution: Dextran and dextrose solutions, LR, Ringer's, Na-bicarb, Na-lactate 1/6 M, IV fat emulsions, invert sugar solutions

            Additive: Amikacin, aztreonam(?), cefepime(?), chlorpromazine, dopamine, gentamicin, heparin(?), hydralazine, hydrocortisone, prochlorperazine,

            Syringe: Erythromycin, gentamicin, hydromorphone, kanamycin, lincomycin, metoclopramide, polymyxin B SO4, streptomycin

            Y-site: Amphotericin B cholesteryl SO4, Ca gluconate, cisatracurium (at high cisatracurium concentration; may be compatible at low concentrations), diltiazem, epinephrine, fenoldopam, fluconazole, hydralazine, midazolam, nicardipine, ondansetron, sargramostim, verapamil, vinorelbine

            IV Compatibilities

            Solution: NS (some contrary reports)

            Additive: Clindamycin, erythromycin, floxacillin, furosemide, metronidazole, verapamil

            Syringe: Chloramphenicol, colistimethate, heparin, lidocaine

            Y-site (partial list): Acyclovir, aztreonam, clarithromycin, cyclophosphamide, esmolol, famotidine, heparin, labetalol, linezolid, KCl, MgSO4, meperidine, propofol, vancomycin, vitamins B/C

            IV Preparation

            Reconstitute with sterile water for injection or bacteriostatic water for injection

            Use 5 mL for 125 mg, 250 mg, or 500 mg vials; 7.4 mL for 1 g vials; or 14.8 mL for 2 g vials

            IV Administration

            Use initial dilution within 1 hr

            Give direct IV over 3-5 min for (125-500 mg) and over 10-15 minutes for larger doses (1-2 g)

            Do not exceed a rate of 100 mg/min

            For intermittent infusion, dilute in 50-100 mL of NS and give over 15-30 min

            Give IV intermittently to prevent vein irritation (change site q48hr)

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            Images

            BRAND FORM. UNIT PRICE PILL IMAGE
            ampicillin oral
            -
            500 mg capsule
            ampicillin oral
            -
            250 mg capsule

            Copyright © 2010 First DataBank, Inc.

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            Patient Handout

            Patient Education
            ampicillin oral

            AMPICILLIN - ORAL

            (AM-pi-SIL-in)

            COMMON BRAND NAME(S): Principen

            USES: Ampicillin is used to treat a wide variety of bacterial infections. It is a penicillin-type antibiotic. It works by stopping the growth of bacteria.This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.

            HOW TO USE: Take this medication by mouth as directed by your doctor, usually 4 times a day (every 6 hours). Take ampicillin on an empty stomach (1 hour before or 2 hours after a meal) with a full glass of water. Drink plenty of fluids while using this medication unless your doctor tells you otherwise.The dosage is based on your medical condition and response to therapy.For the best effect, take this antibiotic at evenly spaced times. To help you remember, take this medication at the same time(s) every day.Continue to take this medication until the full-prescribed amount is finished even if symptoms disappear after a few days. Stopping the medication too early may allow bacteria to continue to grow, which may result in a relapse of the infection.Tell your doctor if your condition lasts or gets worse.

            SIDE EFFECTS: Nausea, vomiting, diarrhea, or mouth/tongue sores may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: nausea or vomiting that doesn't stop, sore throat or fever that doesn't go away, dark urine, stomach/abdominal pain, yellowing eyes or skin, easy bruising or bleeding.This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop: diarrhea that doesn't stop, abdominal or stomach pain/cramping, blood/mucus in your stool.If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.Use of this medication for prolonged or repeated periods may result in oral thrush or a new vaginal yeast infection (oral or vaginal fungal infection). Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge or other new symptoms.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.Ampicillin can commonly cause a mild rash that is usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe allergic reaction. Get medical help right away if you develop any rash.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

            PRECAUTIONS: Before taking ampicillin, tell your doctor or pharmacist if you are allergic to it; or to penicillin or cephalosporin antibiotics; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, a certain type of viral infection (infectious mononucleosis).Ampicillin may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using ampicillin before having any immunizations/vaccinations.Older adults may be at greater risk for side effects while using this drug.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.Ampicillin passes into breast milk. Consult your doctor before breast-feeding.

            DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: methotrexate, tetracyclines.Ampicillin may cause false positive results with certain diabetic urine testing products (cupric sulfate-type). This drug may also affect the results of certain lab tests. Make sure laboratory personnel and your doctors know you use this drug.

            OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: diarrhea that doesn't stop, severe vomiting, unusual change in the amount of urine, or seizures.

            NOTES: Do not share this medication with others.This medication has been prescribed for your current condition only. Do not use it later for another infection unless your doctor tells you to.If you are using this drug for a long time, lab and/or medical tests (such as kidney/liver function, complete blood count) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

            MISSED DOSE: If you miss a dose, use it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Use your next dose at the regular time. Do not double the dose to catch up.

            STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

            Information last revised December 2022. Copyright(c) 2022 First Databank, Inc.

            IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

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            Formulary

            FormularyPatient Discounts

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            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
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            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
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            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
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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.