Ampicillin
Mechanism :
Ampicillin trihydrate is a semisynthetic penicillin. Ampicillin is bactericidal at low concentrations and is effective not only against the gram-positive organisms but also against a variety of gram-negative organisms.
Indication :
- Infections of the Genitourinary Tract Including gonorrhoea
- Infections of the Respiratory Tract
- Infections of the Gastrointestinal Tract
- Bacterial meningitis/septicaemia
- Endocarditis treatment
- Endocarditis prophylaxis (off-label)
- Soft tissue infections
Contraindications :
A history of hypersensitivity to any penicillin is a contraindication. Infectious mononucleosis patients develop a rash, and therefore use is avoided. Renal and hepatic function should be monitored.
Dosing :
In general in children: Oral dose is 50-100 mg/kg/day divided every 6 hours with a maximum dose of 2-4 gm/day.
IV: 100-300 mg/kg/day (based on severity of infection) every 6-8 hourly. For meningitis, use 200-400 mg/kg/day in 4 divided doses for 14 days. Maximum dose: 12 gm/day.
Neonates <7 days of life:
<2000 gm: 50-100 mg/kg/day IV/IM divided into 12 hourly doses.
>2000 gm: 75-150 mg/kg/day IV/IM divided into 8 hourly doses.
Neonates >7 days of life:
<1200 gm: 50-100 mg/kg/day IV/IM divided into12 hourly doses.
1200-2000 gm: 75-150 mg/kg/day IV/IM divided into 8 hourly doses.
>2000 gm: 100-200 mg/kg/day IV/IM divided into 6 hourly doses.
Endocarditis prophylaxis (off-label):
50 mg/kg IV/IM (+/-
gentamicin) within 30-60 minutes before procedure; max dose: 2 gm.
Adverse Effect :
Nausea, vomiting, diarrhea, black hairy tongue, pseudomembranous colitis, serum sickness-like reactions, erythematous maculopapular rashes, erythema multiforme, Stevens-Johnson syndrome, exfoliative dermatitis, toxic epidermal necrolysis, hypersensitivity vasculitis and urticaria.
Interaction :
Probenecid: Decreases the renal tubular secretion of amoxicillin, concurrent use may result in increased and prolonged blood levels of amoxicillin.
Warfarin: Prolongation of prothrombin time.
OCPs: Decreased effectiveness.
Allopurinol: Increases frequency of rashes.
Chloroquine: Reduces absorption of ampicillin.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | 250 mg - 2 g every 6 hours |
| <10 | 250 mg - 1 g every 6 hours |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in GFR<10 mL/min |
| HD | Dialysed. Dose as in GFR<10 mL/ min |
| HDF/High flux | Dialysed. Dose as in GFR<10 mL/ min |
| CAV/VVHD | Dialysed. Dose as in GFR=10-20 mL/min |
Hepatic Dose :
No dosage adjustments are recommended.