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
more...

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
more...

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

Interaction Checker

and ampicillin

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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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.

            more...
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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

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            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            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.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            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.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each 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.