Antitubercular fixed-dose combination (RHZ)
Rifampicin with isoniazid and pyrazinamide
Brand names: Rifater
Adult dose
Dose: Weight-based: 40–49kg = 4 tabs OD; 50–64kg = 5; ≥65kg = 6 tabs PO OD for 2 months
Route: PO
Frequency: OD (intensive)
Clinical pearls
- Older 3-drug FDC; 4FDC (Voractiv) preferred where ethambutol indicated
- Co-prescribe pyridoxine
Contraindications
- Hypersensitivity
- Severe hepatic impairment
- Acute gout
Side effects
- Hepatotoxicity
- Hyperuricaemia / gout
- Peripheral neuropathy
- Orange body fluids
- Cytopenias
Interactions
- Many — strong enzyme inducer
- Hormonal contraceptives
- Allopurinol
Monitoring
- LFTs
- Urate
- FBC
Reference: BNF; NICE NG33; https://bnf.nice.org.uk/drugs/rifampicin-with-isoniazid-and-pyrazinamide/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Infective Endocarditis · ESC 2023 Infective Endocarditis Guidelines; NICE NG41
- Eczema Herpeticum · BAD; NICE CKS
- Suspected Bacterial Meningitis (Adult) · NICE NG240 (2024); NICE NG143 (paeds)
- Clostridioides difficile Colitis · NICE NG199 (2021); IDSA/SHEA 2021
- Returning Traveller — Fever · NaTHNaC; PHE; ESCMID 2018
- Malaria — Diagnosis & Management · PHE 2016; WHO 2023