isoniazid + pyrazinamide + rifampicin at a glance
Medicine class
Fixed-combination antituberculosis antibiotic.
Licensed use
Pulmonary tuberculosis.
Food
Swallow on an empty stomach because food can reduce absorption.
Body fluids
Urine, sweat, saliva and tears may turn orange or red; soft contact lenses can be permanently stained.
What is isoniazid + pyrazinamide + rifampicin used for?
The selected UK product is licensed for:
Pulmonary tuberculosis during the initial intensive treatment phase, under specialist supervision.
How does isoniazid + pyrazinamide + rifampicin work?
Rifampicin blocks bacterial RNA production, isoniazid disrupts mycobacterial cell-wall formation, and pyrazinamide is particularly active inside cells in acidic conditions. Together they target different populations of tuberculosis bacteria.
How to take isoniazid + pyrazinamide + rifampicin
Follow the TB team's instructions exactly. Swallow the tablets whole with water on an empty stomach. Do not stop, restart or change treatment without specialist advice.
Avoid matured cheeses, cured meats, wine, beer and certain fish such as tuna, mackerel and salmon because isoniazid can cause food-related reactions.
Tell the team about all prescribed, pharmacy and herbal products before starting anything new.
Vitamin B6 may be prescribed for people at increased risk of isoniazid-related nerve problems.
isoniazid + pyrazinamide + rifampicin side effects
Common or expected effects
- Nausea, vomiting or diarrhoea
- Headache or dizziness
- Fever, chills or flu-like symptoms
- Joint pain
- Rash or itching
- Tingling or numbness
- Orange or red body fluids
Get urgent medical advice
- Liver injury, including jaundice, dark urine, pale stools, loss of appetite, persistent sickness or upper abdominal pain
- Severe allergic reaction or a blistering, peeling or widespread rash
- Unusual bruising, bleeding, pallor or recurrent infections
- New or suddenly worsening breathlessness, cough or fever
- Kidney problems, including blood in the urine, markedly changed urine output or swelling
- Seizures, hallucinations, severe confusion or loss of coordination
isoniazid + pyrazinamide + rifampicin in pregnancy
Do not stop effective tuberculosis treatment without specialist advice. Use during pregnancy requires an individual benefit–risk assessment, as evidence specifically for this combination is limited. Rifampicin exposure near delivery may increase bleeding risk and prompt consideration of vitamin K.
isoniazid + pyrazinamide + rifampicin while breastfeeding
All three components enter breast milk. Breastfeeding is advised only when the clinician judges that the benefit outweighs potential infant risk. Specialist assessment should consider infant monitoring and whether pyridoxine is appropriate.
isoniazid + pyrazinamide + rifampicin interactions
Rifampicin and isoniazid affect drug-metabolising enzymes and transporters. A full medication review is essential when treatment starts or stops.
Hormonal contraceptives
Rifampicin can reduce effectiveness; discuss alternative or additional contraception promptly.
Warfarin and other anticoagulants
Rifampicin can alter exposure and anticoagulant control, requiring specialist review and monitoring.
Antiretroviral and hepatitis antiviral medicines
Concentrations of several antivirals can fall substantially; some combinations are contraindicated.
Common questions about isoniazid + pyrazinamide + rifampicin
Answers are fully visible for fast scanning and source review.
What is it used for?
The selected UK product is licensed for pulmonary tuberculosis under specialist supervision during the initial intensive treatment phase.
Is it the same as Rifater?
Rifater is the brand name of the selected fixed-combination tablet.
Should it be taken with food?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.