AMCILL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AMCILL (AMCILL).
Ampicillin is a beta-lactam antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death.
| Metabolism | Partially metabolized by hydrolysis; primarily excreted unchanged in urine via renal tubular secretion and glomerular filtration. |
| Excretion | Renal: 60-80% unchanged; biliary: less than 10%; fecal: small amount. |
| Half-life | 1-1.5 hours in normal renal function; prolonged to 7-10 hours in anuria. |
| Protein binding | 20% bound, primarily to albumin. |
| Volume of Distribution | 0.3 L/kg; indicates distribution into extracellular fluid. |
| Bioavailability | Oral: 50-70% (variable, reduced by food); IM: nearly 100%. |
| Onset of Action | Oral: 30-60 minutes; IM: 15-30 minutes; IV: immediate. |
| Duration of Action | 6-8 hours for susceptible organisms; may require more frequent dosing for serious infections. |
250-500 mg orally every 8 hours or 500 mg every 12 hours; for severe infections, up to 1 g every 6 hours intravenously.
| Dosage form | CAPSULE |
| Renal impairment | For CrCl 30-50 mL/min: administer every 12 hours; for CrCl 10-29 mL/min: administer every 18-24 hours; for CrCl <10 mL/min: administer every 24 hours. |
| Liver impairment | No specific adjustments recommended for Child-Pugh A or B; use caution in severe hepatic impairment (Child-Pugh C) with monitoring. |
| Pediatric use | Children >1 month: 25-50 mg/kg/day orally divided every 8 hours; for severe infections, up to 100 mg/kg/day IV divided every 6 hours. Maximum dose: 2 g/day. |
| Geriatric use | No specific dose adjustment required; monitor renal function and adjust based on creatinine clearance. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AMCILL (AMCILL).
| Breastfeeding | Ampicillin is excreted in breast milk in low concentrations (M/P ratio approximately 0.2). Compatible with breastfeeding; monitor infant for diarrhea or rash. |
| Teratogenic Risk | FDA Pregnancy Category B. No evidence of teratogenicity in animal studies. First trimester: Not associated with major birth defects. Second and third trimesters: Use only if clearly needed; potential for altered gut flora and diarrhea in neonate. |
| Fetal Monitoring |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
["Hypersensitivity to ampicillin, penicillins, or any component of the formulation","Infections caused by beta-lactamase-producing organisms"]
| Precautions | ["Hypersensitivity reactions including anaphylaxis","Clostridioides difficile-associated diarrhea","Superinfection","Risk of seizures with high doses or renal impairment","Use caution in patients with mononucleosis (high risk of rash)"] |
| Food/Dietary | Food does not significantly affect absorption; may be taken with or without meals. Avoid alcohol: may increase risk of disulfiram-like reaction (rare). |
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| Monitor for signs of hypersensitivity (rash, anaphylaxis), gastrointestinal disturbances, and superinfection. In prolonged use, monitor renal, hepatic, and hematologic function. |
| Fertility Effects | No known adverse effects on fertility in animal or human studies. |
| Clinical Pearls |
| AMCILL (ampicillin) is a broad-spectrum penicillinase-sensitive penicillin. Use caution in patients with renal impairment; dose adjustment required for CrCl <30 mL/min. Monitor for hypersensitivity reactions, especially in patients with cephalosporin allergy. IV administration may cause phlebitis; rotate infusion sites. Not effective against penicillinase-producing organisms including Staphylococcus aureus. |
| Patient Advice | Take exactly as prescribed; complete full course even if you feel better. · Notify your doctor if you develop rash, hives, or difficulty breathing. · May cause diarrhea; contact your doctor if severe or bloody. · Take with a full glass of water; avoid acidic beverages like orange juice. · Inform your doctor if you are pregnant, breastfeeding, or taking oral contraceptives (ampicillin may reduce efficacy). |