Section 5: Opportunistic Infections (OIs) and important co-infections
HIV only: nevirapine +2 RTIs efavirenz + 2 RTIs
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HIV + TB: efavirenz + 2 RTIs abacavir + 2 other RTIs saquinavir+ritonavir + RTIs
Efavirenz should not be used in pregnant woman (who should use pyrazinamide in their TB regimen) or in women who may become pregnant. Children with low weight are recommended to use abacavir + 2 RTIs.
Summary of drug interactions •
rifampicin should not be taken with any PI or nevirapine because rifampicin reduces these drugs to very low levels
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rifabutin should not be taken with ritonavir, saquinavir or nevirapine
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rifabutin interacts with indinavir, nelfinavir, amprenavir, saquinavir (Fortovase and Invirase) and efavirenz, but appropriate dose adjustments can be made.
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rifabutin levels are increased by PIs
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rifampicin may also interact with other drugs taken by people with HIV
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risk of neuropathy with izoniazid is likely to be increased in people using d4T
When to use ARVs with active TB infection
There are very few trials of how to treat TB in HIV coinfection, so recommendations are based on expert guidelines.
People with a CD4 count under 100, can start TB meds for 2-3 weeks and then start ARVs.
People with a CD4 count between 100 - 200, can usually wait until after the first 2 months TB treatment before starting ARVs.
People whose CD4 count is over 200 can usually finish the 6-month course of TB treatment before starting ARVs.
A serious side effect of the TB-drug izoniazid is peripheral neuropathy (PN). PN can also be caused by HIV and by ARV drugs including d4T, ddI, and 3TC - and this risk increases when both isoniazid and these ARVs are used over the same period.
Sometimes ARV treatment for HIV, especially in people with very low CD4 counts, can cause an immune response that complicates the management of TB (such as IRIS disease). This requires specialist management.
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Prophylaxis: Prophylaxis treatment for TB is usually only recommended in specific circumstances, usually where people share the same confined living or working space - ie family members will often receive treatment if a member of their family is diagnosed with active TB. Secondary prophylaxis, to prevent either TB coming back, or reinfection with a new strain of the virus, is rarely recommended. This is mainly because treatment is difficult to tolerate, and the risk of resistance is high.
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Future research: There is an urgency for new accurate tests for TB and these may become available in the future. This would dramatically improve management and care of HIV-positive people co-infected with TB.
Other antibiotics and regimens are also being studied.
HIV i-Base: basic training for advocates
S5:63
January 2008
OIs
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