Gram-positive: Streptococcus spp., Enterococcus spp., Listeria monocytogenes
Gram-negative: H. influenzae, E. coli, Proteus mirabilis, Salmonella spp., Shigella spp.
Exerts bactericidal activity via inhibition of bacterial cell wall synthesis by binding one or more of the penicillin binding proteins (PBPs). Exerts bacterial autolytic effect by inhibition of certain PBPs related to the activation of a bacterial autolytic process.
Penicillins produce time-dependent killing
Cmax: 40mcg/ml; Half-life: 1-1.3h; Table 6
Hematologic: anemia, thrombocytopenia, neutropenia, agranulocytosis
Renal: nephrotoxicity, interstitial nephritis
Hepatic: transient increases in transaminases
Other: Jarisch-Herxheimer Reaction (fever, chills, sweating, tachycardia, hyperventilation, flushing, and myalgia)
Adult: 250-500mg po q6h
1-2g IV q4h
Pediatric: ³ 1 month and < 40 kg: 50-200 mg/kg day IV in 4-6 divided doses
< 1 week: 25 mg/kg IV/IM q 8-12h
³ 1 week and < 1 month: 25 mg/kg IV/IM q6-8h
> 40 kg: usual adult dose
Renal failure: CrCL 10-50 mL/min: Extend dosing interval to q 6-12h
CrCL < 10 mL/min: Extend dosing interval to q8-16h
hypersensitivity to ampicillin or other penicillins
Patients with mononucleosis are more likely to develop a skin rash
Allopurinol – higher probablility of ampicillin rash; Atenolol – decreased atenolol effectiveness; Contraceptives - decreased contraceptive effectiveness; Lansoprazole – loss of ampicillin efficacy; Live Typhoid Vaccine - decreased immunological response to the typhoid vaccine; Omeprazole – loss of ampicillin efficacy; Pantoprazole – loss of ampicillin efficacy; Probenecid - increased ampicillin levels; Rabeprazole – loss of ampicillin efficacy
Category B:No evidence of risk in humans but studies inadequate.
Therapeutic: Culture and sensitivities, signs and symptoms of infection
Toxic: Periodic CBC, urinalysis, BUN, Creatinine, AST and ALT, diarrhea, skin rash
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