Antistaphylococcal Penicillin·Infectious Diseases - Penicillins

Flucloxacillin

Skin and soft tissue infections, MSSA bacteremia/endocarditis, osteomyelitis

PBSBETA-LACTAMFlopen, Staphylex250 mgS4+1

No source link confirmed for this record yet. Its own source notes are under Additional.

At a glance

Max Dose

8 g/day (IV)

Half-life

1 h

Caution: Phlebitis

HIGH RISK

Empty Stomach

MANDATORY

Cautions

Avoid / Cautions

History of flucloxacillin-induced hepatic dysfunction, severe penicillin allergy. Pregnancy Category B1.

Where it stands

Rapid Summary

Overview

Narrow-spectrum, highly potent anti-staphylococcal penicillin. The definitive first-line treatment for MSSA bacteremia and severe cellulitis.

Clinical Focus

Given IV, it destroys peripheral veins. Given PO, it has terrible bioavailability and MUST be taken on an empty stomach.

Bottom Line

Flucloxacillin is the first-line antistaphylococcal penicillin for skin and soft tissue infections, but carries a significant risk of cholestatic hepatitis especially with courses > 14 days.

Formulation & Access

Brand Names

Flopen, Staphylex

Oral Routes

Capsules (250 mg, 500 mg).

Parenteral

Ampoules (1 g, 2 g) for IV use.

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Skin and soft tissue infections, MSSA bacteremia/endocarditis, osteomyelitis.

Clinical Place

Unmatched efficacy against Methicillin-Susceptible S. aureus (MSSA). Superior to Vancomycin for MSSA.

Quick reference

Class & Role

Antistaphylococcal Penicillin — Narrow-spectrum, highly potent anti-staphylococcal penicillin.

Route / Formulation

Capsules (250 mg, 500 mg). (Flopen, Staphylex)

Usual Dose & Max

IV 2 g q6h (8 g/day). Max 8 g/day (IV) or 4 g/day (PO).

Key Indication Doses

Severe Cellulitis / MSSA Bacteremia: IV 2 g q6h (8 g/day). Mild/Moderate Skin Infection: PO 500 mg to 1 g QID. Strictly 1 hr before or 2 hrs after food. Renal Impairment: Reduce IV dose to 1 g q6h or q8h if eGFR < 30.

Best Uses

Flucloxacillin is the first-line antistaphylococcal penicillin for skin and soft tissue infections, but carries a significant risk of cholestatic hepatitis especially with courses > 14 days.

Key Risks

Tissue: Severe chemical phlebitis and vein thrombosis via peripheral IV. Hepatic: Cholestatic hepatitis. Risk increases with age > 55 and courses > 14 days. Renal: Interstitial nephritis.

Key Interactions

Paracetamol. Co-administration of IV Flucloxacillin and high-dose Paracetamol in malnourished/elderly women can trigger severe High Anion Gap Metabolic Acidosis (HAGMA) due to 5-oxoproline accumulation.

Monitoring

Monitor LFTs regularly if used IV for prolonged periods (e.g., osteomyelitis). Inspect peripheral IV cannula sites strictly every shift for redness/pain.

Clinical Pearl

Oral flucloxacillin absorption drops by 50% if taken with food. Ward nurses routinely give it with meals to prevent nausea, guaranteeing sub-therapeutic blood levels and clinical failure. Prescribe it exactly 1 hr before meals.

Access

Flopen, Staphylex250 mg

Brand: Flopen, Staphylex
Formulation: Capsules (250 mg, 500 mg).

From this page

No calculator, monitoring schedule or factsheet is linked to this medicine page yet.

Antistaphylococcal Penicillin·Infectious Diseases - Penicillins

Flucloxacillin

Skin and soft tissue infections, MSSA bacteremia/endocarditis, osteomyelitis

PBSBETA-LACTAMFlopen, Staphylex250 mgS4+1

No source link confirmed for this record yet. Its own source notes are under Additional.

At a glance

Max Dose

8 g/day (IV)

Half-life

1 h

Caution: Phlebitis

HIGH RISK

Empty Stomach

MANDATORY

Cautions

Avoid / Cautions

History of flucloxacillin-induced hepatic dysfunction, severe penicillin allergy. Pregnancy Category B1.

Where it stands

Rapid Summary

Overview

Narrow-spectrum, highly potent anti-staphylococcal penicillin. The definitive first-line treatment for MSSA bacteremia and severe cellulitis.

Clinical Focus

Given IV, it destroys peripheral veins. Given PO, it has terrible bioavailability and MUST be taken on an empty stomach.

Bottom Line

Flucloxacillin is the first-line antistaphylococcal penicillin for skin and soft tissue infections, but carries a significant risk of cholestatic hepatitis especially with courses > 14 days.

Formulation & Access

Brand Names

Flopen, Staphylex

Oral Routes

Capsules (250 mg, 500 mg).

Parenteral

Ampoules (1 g, 2 g) for IV use.

Prescribing & PBS

Unrestricted General Benefit (S4).

Indications & Use

Primary

PBSTGA

Skin and soft tissue infections, MSSA bacteremia/endocarditis, osteomyelitis.

Clinical Place

Unmatched efficacy against Methicillin-Susceptible S. aureus (MSSA). Superior to Vancomycin for MSSA.

Quick reference

Class & Role

Antistaphylococcal Penicillin — Narrow-spectrum, highly potent anti-staphylococcal penicillin.

Route / Formulation

Capsules (250 mg, 500 mg). (Flopen, Staphylex)

Usual Dose & Max

IV 2 g q6h (8 g/day). Max 8 g/day (IV) or 4 g/day (PO).

Key Indication Doses

Best Uses

Flucloxacillin is the first-line antistaphylococcal penicillin for skin and soft tissue infections, but carries a significant risk of cholestatic hepatitis especially with courses > 14 days.

Key Risks

Tissue: Severe chemical phlebitis and vein thrombosis via peripheral IV. Hepatic: Cholestatic hepatitis. Risk increases with age > 55 and courses > 14 days. Renal: Interstitial nephritis.

Key Interactions

Monitoring

Monitor LFTs regularly if used IV for prolonged periods (e.g., osteomyelitis). Inspect peripheral IV cannula sites strictly every shift for redness/pain.

Clinical Pearl

Access

Flopen, Staphylex250 mg

Brand: Flopen, Staphylex
Formulation: Capsules (250 mg, 500 mg).

From this page

No calculator, monitoring schedule or factsheet is linked to this medicine page yet.