Penicillin (penicillinase-resistant penicillin)
Staphylococcus spp., Streptococcal spp.
Mechanism of Action:
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: 52-63 mcg/ml; Half-life: 0.5-0.7 hours; Table 6
Hematologic: neutropenia, inhibition of platelet aggregation, eosinophilia, thrombocytopenia,
Renal: acute interstitial nephritis, hematuria
Hepatic: transient increases in transaminases
Other: thrombophlebitis, Jarisch-Herxheimer Reaction (fever, chills, sweating, tachycardia, hyperventilation, flushing, and myalgia)
Adult: 500mg-1g po q4-6h or 1-2g IV q4-6h
Pediatric: > 1 month and < 40kg: 50-100 mg/kg/day po or IV in 4 divided doses
³ 40 kg: usual adult dose
Disease state based dosing:
Renal failure: CrCL < 10 mL/min: use lower range of usual dose
Dosing during Continuous Renal Replacement Therapy
CVVH (Continuous venovenous hemofiltration): 2g IV q4-6h
CVVHD (Continuous venovenous hemodialysis): 2g IV q4-6h
CVVHDF (Continuous venovenous hemodiafiltration) 2g IV q4-6h
Note: CVVH is mainly for fluid removal alone. Many institutions will employ more CVVHD or CVVHDF which combine dialysis with fluid removal.
Contraindications: Anaphylaxis to penicillin or other penicillins
Contraceptives - decreased contraceptive effectiveness
Live Typhoid Vaccine - decreased immunological response to the typhoid vaccine
Probenecid - increased oxacillin levels
Warfarin - decreased anticoagulant effectiveness
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, SCr, AST and ALT