Dicloxacillin
DYNAPEN
Pronunciation: dye-klox-a-SIL-in
“Dyed clocks a’ ceiling”
Β lactam ring → the defining structure of penicillins and cephalosporins
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.
Dicloxacillin prescription history
Animated chart of estimated U.S. prescriptions per year, Penicillins (oral) (1955–2026). Dicloxacillin enters in 1968 (estimated).
FDA-approved for
- staphylococcal skin infections (1968)
Principal riskFour-times-daily fasting; it reduces warfarin effect
Classes and tags
Clinical profile
Legacy pregnancy categoryB
Defining liabilityAllergy, gastrointestinal effects and agent-specific renal, hepatic, hematologic or interaction risks.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| 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
Instructions
- 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
Available strengths
- cap 250, 500 mg
Cautions
- Serious and occasionally fatal hypersensitivity (anaphylactic) reactions, especially in penicillin-sensitive patients
- Esophageal irritation risk if taken supine or with inadequate water
Adverse reactions
- 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
Cost
Generic entry1982
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Memory aids: interaction avatars
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Self-check
- How often and relative to food is dicloxacillin taken?
Four times daily on an empty stomach. - How does dicloxacillin affect warfarin?
Reduces its effect.