Anti-infective
Tuberculosis drugs
Anti-TB drugs (antitubercular medicines) — Combination therapy taken over months to cure tuberculosis and prevent resistance — adherence is essential and sometimes directly observed.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
Quick answer
What is Tuberculosis drugs?
Tuberculosis (TB) is a bacterial infection, usually of the lungs, that needs several drugs taken together over months rather than a single antibiotic for a short course. Standard treatment runs in two phases — an initial intensive phase using several drugs, followed by a longer continuation phase with fewer — and the whole course must be completed to clear the infection.
- How it works: TB bacteria grow slowly and can lie dormant, so the disease is hard to eradicate and quick to develop resistance if treated with one drug alone.
- In practice: In practice, treatment is managed by TB services, and completing the full course matters more than almost anything else — incomplete treatment is the main driver of multidrug-resistant TB, which is why directly observed therapy is used where adherence is uncertain.
What it is
Tuberculosis (TB) is a bacterial infection, usually of the lungs, that needs several drugs taken together over months rather than a single antibiotic for a short course. Standard treatment runs in two phases — an initial intensive phase using several drugs, followed by a longer continuation phase with fewer — and the whole course must be completed to clear the infection. Newer agents are reserved for TB that has become resistant to the usual drugs.
How it works
TB bacteria grow slowly and can lie dormant, so the disease is hard to eradicate and quick to develop resistance if treated with one drug alone. Combining drugs that kill the bacteria in different ways — isoniazid, rifampicin, pyrazinamide and ethambutol in standard regimens — clears the infection while preventing resistant strains from emerging. For drug-resistant disease, newer agents such as bedaquiline, pretomanid and delamanid act through different mechanisms and are combined under specialist guidance.
In practice
In practice, treatment is managed by TB services, and completing the full course matters more than almost anything else — incomplete treatment is the main driver of multidrug-resistant TB, which is why directly observed therapy is used where adherence is uncertain. Rifampicin is a potent enzyme inducer that reduces the effect of many drugs, including hormonal contraception, so co-medication is reviewed carefully and patients are warned their urine, tears and other secretions will turn orange. Isoniazid can cause peripheral neuropathy, prevented with pyridoxine, and several of these drugs are hepatotoxic, so liver function and symptoms are watched closely. Ethambutol requires checks of vision, as it can affect the optic nerve.
Examples
Practical use
How to take it & use it well
- Take the combination of TB medicines every day exactly as prescribed and complete the full course, which lasts months, even after you feel well.
- Do not stop early or skip doses, as this is the main way that TB becomes resistant and far harder to treat, sometimes for everyone around you too.
- Understand that several medicines are combined precisely to stop the bacteria becoming resistant, so all of them matter, not just the one you feel is helping.
- If you are prescribed vitamin B6 alongside, take it as directed, as it helps prevent the nerve tingling that one of the TB medicines can cause.
- Tell your team if you cannot keep doses down or develop side effects, rather than just stopping, so the plan can be adjusted while keeping you protected.
- Keep all your appointments and blood tests, which check your liver and how treatment is going, and report any new symptoms promptly.
Common uses
- Treatment of active pulmonary and extrapulmonary TB
- Treatment of latent TB infection
- Drug-resistant and multidrug-resistant TB (newer agents)
- Specialist-supervised combination regimens
Monitoring
- Liver function and symptoms of hepatotoxicity
- Visual acuity and colour vision with ethambutol
- Adherence (sometimes by directly observed therapy) and clinical and microbiological response
Weighing it up
Advantages & disadvantages
Advantages
- Taken fully, the combination cures the great majority of tuberculosis.
- Combining several medicines prevents the bacteria becoming resistant.
- Most people start to feel better within weeks of starting treatment.
- Successful treatment also stops the infection being passed on to others.
- The approach is well established, with clear, proven regimens and monitoring.
Disadvantages
- It is a long course of several medicines, which takes commitment to complete.
- Stopping early or missing doses can lead to resistant TB that is much harder to cure.
- Rifampicin turns urine, tears and other fluids a harmless orange-red, which can stain soft contact lenses.
- These medicines can affect the liver, so monitoring and prompt reporting of symptoms are needed.
- Some can affect the nerves or the eyes, which is watched for and reported.
Key safety principles
What to watch for
- TB is treated with combination therapy over months — never with a single drug, which breeds resistance.
- Completing the full course is essential; incomplete treatment drives drug-resistant TB.
- Rifampicin induces liver enzymes and reduces the effect of many drugs, including hormonal contraception.
- Several agents are hepatotoxic — liver function and warning symptoms must be monitored.
- Isoniazid can cause peripheral neuropathy, usually prevented with pyridoxine.
- Ethambutol can affect vision, so eyesight is checked before and during treatment.
Key interactions
What to avoid or check alongside
- Rifampicin is a strong enzyme inducer that speeds up the breakdown of many medicines, making hormonal contraception, some HIV treatments and blood thinners less reliable.
- Isoniazid can cause tingling or numbness in the hands and feet, which is why vitamin B6 is often given to prevent it.
- Ethambutol can affect the eyes and colour vision, so any change in your sight should be reported straight away.
- These medicines can affect the liver, so report jaundice, dark urine, persistent nausea or tummy pain, and avoid unnecessary alcohol.
- Tell every prescriber and pharmacist that you take TB treatment, especially while on rifampicin, as it can disturb the levels of many other medicines.
Patient & carer advice
- Take every dose for the whole course, even once you feel well — stopping early lets the infection return resistant
- Rifampicin turns urine, tears and sweat orange-red and can stain soft contact lenses
- Use additional or alternative contraception if you take rifampicin, as the pill may not work
- Report yellowing of the eyes or skin, nausea, tingling in the hands or feet, or any change in vision
Answers
Tuberculosis drugs: frequently asked questions
Why must I finish the whole course of TB treatment?
TB bacteria are slow to clear, so a long course is needed to kill them all, even though you feel better within weeks. Stopping early leaves survivors that can become resistant, making the infection much harder to treat and able to spread to others. Completing every dose is essential to a cure.
Why do I take several different TB medicines at once?
Using a combination of medicines together is what stops the bacteria becoming resistant. If only one were used, the bacteria could quickly learn to survive it. Each medicine plays a part, so all of them matter, not just the one you feel is working. Take them all exactly as prescribed.
Why is my urine orange-red on TB treatment?
This is caused by rifampicin, which can turn your urine, tears, sweat and other fluids a harmless orange-red colour. It is expected and not a sign of harm, but it can permanently stain soft contact lenses, so wearing glasses during treatment may be easier.
Can TB medicines stop my contraception working?
Yes. Rifampicin speeds up how the body breaks down several medicines, including hormonal contraception such as the pill and implant, making them less reliable. If you take TB treatment and need contraception, ask your team about methods that are not affected so you stay protected.
What side effects should I report straight away?
Tell your team promptly about yellowing of the eyes or skin, dark urine, persistent nausea or tummy pain, which can signal a liver problem, and about any change in your vision or colour vision. Also report tingling in the hands or feet. Early reporting lets the plan be adjusted safely.
Authoritative sources
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