Antibiotic — Rifamycin (Adjunct Only) Pregnancy: At very high doses rifampicin has been shown to be teratogenic in animals; there are no well-controlled studies in pregnant women. Rifampicin crosses the placental barrier and appears in cord blood. Use in pregnant women or women of child-bearing potential only if the potential benefit justifies the potential risk to the foetus. Administration during the last few weeks of pregnancy may cause post-natal haemorrhage in mother and infant, for which vitamin K1 may be indicated. Rifampicin is excreted in breast milk — infants should not be breast fed by a patient receiving rifampicin unless the physician judges the benefit outweighs the risk.

Rifampicin (Burns — MRSA Adjunct/Biofilm)

Brand names: Rifadin, Rimactane

Rifampicin is a rifamycin antibacterial used in burns care as an adjunctive agent against staphylococcal infection, particularly meticillin-resistant Staphylococcus aureus, where its biofilm and intracellular penetration may add value alongside a primary anti-staphylococcal drug.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Serious staphylococcal infections (listed in the SPC together with brucellosis and Legionnaires' disease): 600 mg to 1200 mg daily, given in 2 to 4 divided doses, together with another appropriate antibiotic to prevent the emergence of resistant strains of the infecting organism

Route: Oral (the fetched SPC is for Rifampicin 150 mg Capsules — for oral administration only)

Frequency: Daily total dose divided into 2 to 4 doses

Max: 1200 mg daily for this indication. A daily dose of 8 mg/kg should not be exceeded in patients with impaired liver function

Source: UK SPC (eMC) for Rifampicin 150 mg Capsules, §4.2 (https://www.medicines.org.uk/emc/product/8788/smpc). The SPC has NO burns-specific or biofilm indication; the regimen above is the SPC's 'serious staphylococcal infections' entry, which is the closest labelled match for an MRSA adjunct — clinician to confirm against local burns/MRSA protocol. RIFAMPICIN MUST NOT BE USED AS A SINGLE AGENT: the SPC repeatedly requires co-administration with another appropriate antibiotic to prevent emergence of resistant strains. ADMINISTRATION: the daily dose, calculated from the patient's body weight, should preferably be taken on an empty stomach or at least 30 minutes before a meal or 2 hours after a meal to ensure rapid and complete absorption. OTHER INDICATIONS (§4.2): tuberculosis — single daily dose 8-12 mg/kg (usual daily dose 450 mg if <50 kg, 600 mg if >=50 kg), always with other effective anti-tuberculosis drugs; prophylaxis of meningococcal meningitis — 600 mg twice daily for 2 days; leprosy — 600 mg once per month (or, if a daily regimen is indicated, 10 mg/kg: 450 mg if <50 kg, 600 mg if >=50 kg), always with at least one other anti-leprosy drug; prophylaxis of Haemophilus influenzae (adults and children >=1 month) — 20 mg/kg once daily (maximum daily dose 600 mg) for 4 days. MONITORING (§4.4): pre-treatment liver function measurements in all tuberculosis patients; baseline hepatic enzymes, bilirubin, serum creatinine, full blood count and platelet count in adults treated for tuberculosis; withdraw if signs of hepatocellular damage occur; give under the supervision of a respiratory or other suitably qualified physician. US labelling (Rifadin IV, https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=82e2bbb1-cc73-4fbd-8d85-610634876355) states that IV doses are the same as those for oral, but gives no regimen for staphylococcal infections — the IV route/dose for this indication is not established in either fetched label.

Dose adjustments

Renal

No numeric adjustment stated in §4.2. §4.4 advises that caution should be taken in case of renal impairment if the dose exceeds 600 mg/day.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Presence of jaundice
Hypersensitivity to rifampicin or to any of the excipients
Concurrent administration with the combination of saquinavir/ritonavir
Medicines strongly affected by rifampicin's potential to induce drug metabolising enzymes and transporters, such as lurasidone, sofosbuvir, and the antiretrovirals cabotegravir, fostemsavir and lenacapavir

Side effects

Common: nausea, vomiting; headache, dizziness; uncommon diarrhoea
Common: thrombocytopenia with or without purpura (usually with intermittent therapy; reversible if the drug is discontinued as soon as purpura occurs); uncommon leucopenia
Not known: drug-induced liver injury including fatal cases (especially in combination with other anti-tuberculosis drugs), hepatitis, hyperbilirubinaemia
Not known: severe cutaneous reactions — erythema multiforme including Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS, acute generalized exanthematous pustulosis; pruritus, rash, urticaria
Not known: acute kidney injury (usually renal tubular necrosis or tubulointerstitial nephritis), chromaturia and discoloration of tears/sweat, anaphylactic reaction, shock, interstitial lung disease

Interactions

Potent inducer of drug metabolising enzymes and transporters — CYP1A2, 2B6, 2C8, 2C9, 2C19 and 3A4, UDP-glucuronyltransferases, sulfotransferases, carboxylesterases, P-glycoprotein and MRP2; rifampicin may increase the metabolism and decrease the activity of many co-administered drugs, or increase the activity of a co-administered pro-drug (US label, Drug Interactions)
Ritonavir-boosted saquinavir — severe hepatocellular toxicity; concomitant use contraindicated
Other hepatotoxic medicines (e.g. halothane, isoniazid) — increased potential for hepatotoxicity; concomitant rifampicin and halothane should be avoided, and patients receiving rifampicin plus isoniazid should be monitored closely for hepatotoxicity
Praziquantel, lurasidone, atazanavir, darunavir, fosamprenavir, saquinavir, tipranavir, cabotegravir, fostemsavir, lenacapavir — contraindicated in the US labelling because of substantially decreased plasma concentrations (loss of efficacy/resistance)
UK SPC §4.5 was not retrieved in this bundle — verify the full interaction section

Clinical monograph

How it works

It inhibits bacterial DNA-dependent RNA polymerase, suppressing RNA synthesis, and penetrates biofilm and phagocytes well, but rapid resistance emerges if it is used alone.

Prescribing in practice

Never use rifampicin as monotherapy for staphylococcal infection because resistance develops quickly; it must be combined with another active anti-staphylococcal agent.
It is a potent inducer of hepatic cytochrome P450 enzymes and causes numerous clinically important interactions, reducing the effect of many co-administered drugs.
Warn that it imparts a harmless red-orange discolouration to urine, sweat, tears and other body fluids and can stain soft contact lenses.

Monitoring

Monitor liver function and full blood count during therapy, with microbiology guidance on combination choice and duration.

Counselling the patient

Body fluids may turn red-orange, which is expected and harmless.
Tell the team about all other medicines, as rifampicin can weaken many of them, including hormonal contraception.
Report nausea, jaundice or unusual bruising.

Evidence & guidelines

Rifampicin combination therapy for resistant staphylococcal infection reflects established microbiological principles and MHRA-recognised resistance concerns.

Reference: BSAC Guidelines on Staphylococcal Infection; MHRA Drug Safety Update; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators