TB that is resistant to isoniazid and rifampicin, and to other drugs as well, is becoming much more common. This is called multidrug-resistant TB (MDR-TB) and cases have been seen in HIV-positive people.

Unlike drug-sensitive TB, which is normally cured, the risk of dying from multidrug-resistant TB is higher, unless you very quickly receive treatment consisting of anti-TB drugs that still work.

In the early 1990s, there were outbreaks of multidrug-resistant TB on HIV wards in two UK hospitals but, thanks to effective infection-control measures, there has not been an outbreak for many years.

To help control the spread of multidrug-resistant TB, it is often necessary for a person with it to stay in hospital in isolation, until treatment has started to be effective.

Treating multidrug-resistant TB is much harder than treating normal drug-sensitive TB. People who have it need to take more anti-TB drugs for longer. Treatment for up to two years or in some cases even longer may be required. Drugs used to treat multidrug-resistant TB include streptomycin, kanamycin, clarithromycin, amikacin, capreomycin, and quinolones.

Some of these drugs can also interact with anti-HIV medication or have unpleasant side-effects and close monitoring is needed.  It is very important that you complete the whole course of treatment, so do talk to your doctor about side-effects and what can be done to make them easier to manage.

Multidrug-resistant TB is more difficult to treat, so it is likely you will be referred to a doctor who specialises in treating TB.

Some strains of TB have also emerged which are resistant to second choice drugs as well; this is called extensively drug-resistant TB (XDR-TB). There have been outbreaks of XDR-TB in a number of places across the world, often involving people with HIV.

The risk of death from extensively drug-resistant TB is very high. There have been no cases of extensively drug-resistant TB in people with HIV in the UK to date.