Dicloxacillin

DYNAPEN

What it isPenicillinase-resistant penicillin; staphylococcal skin and soft tissue infection.

Why this oneUnlike nafcillin or oxacillin, it is taken orally, fitting outpatient treatment of uncomplicated MSSA skin infection.

What limits itNo MRSA cover. Four-times-daily on an empty stomach; it reduces warfarin effect.

FDA-approved for

FDA dosing	Population	Start	Target
Mild to moderate infections	Adults & children ≥40 kg	125 mg q6h	125 mg q6h
Severe infections	Adults & children ≥40 kg	250 mg q6h	250 mg q6h
Mild to moderate infections	Children <40 kg	12.5 mg/kg/day divided q6h	12.5 mg/kg/day divided q6h
Severe infections	Children <40 kg	25 mg/kg/day divided q6h	25 mg/kg/day divided q6h

Renal Undefined

Hepatic Undefined

Take on an empty stomach, at least 1 hour before or 2 hours after meals
Take with at least 4 fluid ounces (120 mL) of water
Do not take in the supine position or immediately before bed
Not for initial therapy of serious, life-threatening infections; may follow parenteral therapy

Serious and occasionally fatal hypersensitivity (anaphylactic) reactions, especially in penicillin-sensitive patients
Esophageal irritation risk if taken supine or with inadequate water

Hypersensitivity reactions (urticaria, pruritus, rash, angioedema, laryngospasm, anaphylaxis; serum sickness-like reactions)
Gastrointestinal reactions

Pregnancy Use during pregnancy only if clearly needed; animal studies show no evidence of fetal harm.

Lactation Undefined

NO BOXED WARNINGS

Principal riskFour-times-daily fasting; it reduces warfarin effect

Cost, est. cash$10–$300/month

Generic entry1982

Therapeutic safety burden1 / 4

Overdose danger1 / 4

Weight-gain liability0 / 4

Sedation liability0 / 4

QT / Torsades0 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk0 / 4

Legacy pregnancy categoryB

Defining liabilityAllergy, gastrointestinal effects and agent-specific renal, hepatic, hematologic or interaction risks.

OAT substrate