Penicillin (penicillinase-resistant penicillin)
Staphylococcus spp., Streptococcal 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: 7.5-14mcg/ml; Oral bioavailability: 50%; Half-life: 0.5 hours; Table 6
Hematologic: neutropenia, inhibition of platelet aggregation
CNS: seizures
Hepatic: transient increases in transaminases
Other: Jarisch-Herxheimer Reaction (fever, chills, sweating, tachycardia, hyperventilation, flushing, and myalgia)
Adult: 250-500mg po q6h
Pediatric: > 1 month and < 20 kg: 50-100 mg/kg/day po in 4 divided doses
³ 20 kg: usual adult dose
Disease state based dosing: No information
Contraindications/Warnings/Precautions:
Contraindications: Anaphylaxis to cloxacillin or other penicillins
Precautions: Cephalosporin hypersensitivity
Contraceptives - decreased contraceptive effectiveness
Live Typhoid Vaccine - decreased immunological response to the typhoid vaccine
Probenecid - increased cloxacillin levels
Warfarin - decreased anticoagulant effectiveness
Pregnancy:
Category B: No evidence of risk in humans but studies inadequate.
Monitoring Requirements:
Therapeutic: Culture and sensitivities, signs and symptoms of infection
Toxic: Periodic CBC, urinalysis, BUN, SCr, AST and ALT
Brand names/Manufacturer: Available by many names and manufacturers (click here)