Dicloxacillin

Antistaphylococcal Penicillin·Infectious Diseases - Penicillins

Cellulitis, impetigo, mastitis, MSSA step-down therapy

PBSBETA-LACTAMDiclocil250 mgS4+1

Max Dose

4 g/day

Half-life

1 h

Empty Stomach

MANDATORY

Hepatotoxicity

HIGH RISK

Rapid Summary

Overview

Narrow-spectrum, oral anti-staphylococcal penicillin. The direct oral equivalent to IV Flucloxacillin for MSSA skin and soft tissue infections.

Maximum Dose

Max 4 g/day (e.g., 1 g QID).

Clinical Focus

Terrible oral bioavailability if taken with food. Must be taken on a strictly empty stomach.

Bottom Line

Dicloxacillin is an oral antistaphylococcal penicillin alternative to flucloxacillin, but has the same hepatotoxicity risk and must be taken on an empty stomach for adequate absorption.

Formulation & Access

Brand Names

Diclocil

Oral Routes

Capsules (250 mg, 500 mg). Large capsules, notoriously foul-tasting if they burst.

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Cellulitis, impetigo, mastitis, MSSA step-down therapy.

Clinical Place

Often chosen over Flucloxacillin PO in some regions due to slightly better oral absorption, but carries the exact same clinical rules.

Quick reference

Class & Role

Antistaphylococcal Penicillin — Narrow-spectrum, oral anti-staphylococcal penicillin.

Route / Formulation

Capsules (250 mg, 500 mg). Large capsules, notoriously foul-tasting if they burst. (Diclocil)

Usual Dose & Max

PO 500 mg QID (1 hour before or 2 hours after meals). Max 4 g/day (e.g., 1 g QID).

Key Indication Doses

Skin / Soft Tissue Infection: PO 500 mg QID (1 hour before or 2 hours after meals). Severe Osteomyelitis (Step-down): PO 1 g QID (Requires extremely high doses to penetrate bone). Renal Impairment: No dose adjustment required in mild-moderate CKD due to heavy hepatic clearance.

Best Uses

Dicloxacillin is an oral antistaphylococcal penicillin alternative to flucloxacillin, but has the same hepatotoxicity risk and must be taken on an empty stomach for adequate absorption.

Avoid / Cautions

History of Dicloxacillin/Flucloxacillin-induced liver injury. Severe penicillin allergy. Pregnancy Category B1.

Key Risks

Hepatic: Cholestatic jaundice and hepatitis. Risk is highest in older adults (>55 years) and with prolonged courses (>14 days). Gastrointestinal: Nausea, abdominal pain, C. diff diarrhea. Immunological: Anaphylaxis, hypersensitivity rash.

Key Interactions

Food severely impairs absorption. Probenecid blocks renal tubular secretion, doubling blood levels (often used intentionally in bone infections).

Monitoring

Monitor LFTs if the patient is on a prolonged course (e.g., 6 weeks for osteomyelitis). Ensure strict education regarding empty stomach administration.

Clinical Pearl

Like Augmentin and Flucloxacillin, Dicloxacillin can cause severe cholestatic jaundice up to 2 months AFTER the patient has finished the antibiotics. Warn patients to watch out for dark urine or yellow eyes post-treatment.

Access

Diclocil250 mg

Brand: Diclocil
Formulation: Capsules (250 mg, 500 mg)

Dicloxacillin

Antistaphylococcal Penicillin·Infectious Diseases - Penicillins

Cellulitis, impetigo, mastitis, MSSA step-down therapy

PBSBETA-LACTAMDiclocil250 mgS4+1

Max Dose

4 g/day

Half-life

1 h

Empty Stomach

MANDATORY

Hepatotoxicity

HIGH RISK

Rapid Summary

Overview

Narrow-spectrum, oral anti-staphylococcal penicillin. The direct oral equivalent to IV Flucloxacillin for MSSA skin and soft tissue infections.

Maximum Dose

Max 4 g/day (e.g., 1 g QID).

Clinical Focus

Terrible oral bioavailability if taken with food. Must be taken on a strictly empty stomach.

Bottom Line

Dicloxacillin is an oral antistaphylococcal penicillin alternative to flucloxacillin, but has the same hepatotoxicity risk and must be taken on an empty stomach for adequate absorption.

Formulation & Access

Brand Names

Diclocil

Oral Routes

Capsules (250 mg, 500 mg). Large capsules, notoriously foul-tasting if they burst.

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Cellulitis, impetigo, mastitis, MSSA step-down therapy.

Clinical Place

Often chosen over Flucloxacillin PO in some regions due to slightly better oral absorption, but carries the exact same clinical rules.

Quick reference

Class & Role

Antistaphylococcal Penicillin — Narrow-spectrum, oral anti-staphylococcal penicillin.

Route / Formulation

Capsules (250 mg, 500 mg). Large capsules, notoriously foul-tasting if they burst. (Diclocil)

Usual Dose & Max

PO 500 mg QID (1 hour before or 2 hours after meals). Max 4 g/day (e.g., 1 g QID).

Key Indication Doses

Best Uses

Dicloxacillin is an oral antistaphylococcal penicillin alternative to flucloxacillin, but has the same hepatotoxicity risk and must be taken on an empty stomach for adequate absorption.

Avoid / Cautions

History of Dicloxacillin/Flucloxacillin-induced liver injury. Severe penicillin allergy. Pregnancy Category B1.

Key Risks

Key Interactions

Food severely impairs absorption. Probenecid blocks renal tubular secretion, doubling blood levels (often used intentionally in bone infections).

Monitoring

Monitor LFTs if the patient is on a prolonged course (e.g., 6 weeks for osteomyelitis). Ensure strict education regarding empty stomach administration.

Clinical Pearl

Access

Diclocil250 mg

Brand: Diclocil
Formulation: Capsules (250 mg, 500 mg)