Description

An antibiotic in the penicillin class (β-lactam), primarily used to treat infections caused by penicillinase-producing staphylococci and other Gram-positive organisms .

Prescription

Yes—prescription-only medicine (POM).

Therapeutic Category

Antibiotic, specifically a β-lactam penicillinase-resistant penicillin.

Active Ingredients / Composition

• Active: Flucloxacillin sodium (equivalent to 500 mg flucloxacillin) per capsule.
• Excipients: Include magnesium stearate, sodium starch glycolate, gelatin, and colorants like iron oxides and titanium dioxide; some formulations also contain sodium (e.g. ~45 mg per 500 mg capsule).

Vitamins / Minerals

None present .

Variant

Hard gelatin capsules (size 0), typically blue/blue, marked “fluc/500.

Consume Type

Oral administration—swallowed with a full glass of water.

Directions / Usage

• Adults: Standard dose is 250 mg four times daily; for more severe infections, 500 mg four times daily may be used.
• Severe cases (e.g., osteomyelitis, endocarditis): Up to 8 g daily in divided doses.
• Surgical prophylaxis: 1–2 g IV at induction, followed by 500 mg every six hours for up to 72 hours.
• Children:
  • <2 years: 62.5 mg four times daily
    2–10 years: 125 mg four times daily
  • Adolescents (10–18 years): 250 mg four times daily.
• Administration tips: Take on an empty stomach—1 hour before or 2 hours after meals—and remain upright with a full glass of water to lessen esophageal irritation.

Common Side Effects

• Common: Diarrhea, nausea, stomach upset, skin rash, itching.
• Serious (seek immediate help): Severe allergic reactions (e.g., swelling, breathing difficulty), significant diarrhoea, jaundice, Stevens–Johnson syndrome, toxic epidermal necrolysis.
• Rare: Blood disorders, metabolic acidosis (especially with paracetamol), cholestatic hepatitis (more likely in older adults, treatment over 2 weeks)

Package Type

Usually supplied in blister packs or HDPE containers, with pack sizes ranging from 7 to 1,000 capsules depending on manufacturer and region.

Storage Advice

Store below 25 °C, in a dry place, and keep in the original packaging to protect from moisture and light.

Safety Advice

• Do not use if allergic to penicillins or cephalosporins, or if prior flucloxacillin-related liver issues occurred.
• Use caution if the patient has kidney or liver impairment; adjust dosing or monitor as needed.
• Drug interactions: Methotrexate, probenecid, paracetamol (risk of metabolic acidosis), warfarin, others.
• Pregnancy / breastfeeding: Should be used with caution; consult a healthcare professional.
• Monitoring: For long-term use, consider liver and kidney function tests.

Product Substitutes

Other flucloxacillin brands include:

• Floxapen,
• Staphylex,
• Fluclomix,
• Sandoz flucloxacillin, etc.

Manufacturer / Marketer

• Vega Biotec Pvt Ltd (India) markets Penflox in Ghana.
• Other manufacturers by region include Pharmaclarity Ltd (UK), Flamingo Pharma UK Ltd, Athlone Laboratories (Ireland) depending on your locale.

Country of Origin

• India for Vega’s Penflox.
• UK or Ireland are common origins for other branded variants