Disseminated Mycobacterium avium complex infection
Disseminated Mycobacterium avium complex infection occurs most commonly in immunocompromised patients, notably those with advanced HIV infection. It is common for patients with advanced HIV infection to have other opportunistic infections in addition to disseminated Mycobacterium avium complex infection.
For primary treatment of disseminated Mycobacterium avium complex infection in adults, a three-drug regimen (including a macrolide, ethambutol and rifabutin) is required; use:
1 clarithromycin 500 mg orally, 12-hourly. For dosage adjustment in adults with kidney impairment, see clarithromycin dosage adjustment MAC, disseminated infection clarithromycin
OR
2 azithromycin 500 mg orally, daily1 MAC, disseminated infection azithromycin
PLUS (with either of the above regimens)
ethambutol 15 mg/kg orally, daily. For dosage adjustment in adults with kidney impairment, see ethambutol (daily regimen) dosage adjustment MAC, disseminated infection ethambutol
PLUS
rifabutin 300 mg orally, daily. MAC, disseminated infection rifabutin
Patients with undiagnosed HIV infection may present initially with M. avium complex infection. In patients who need to be started on therapy for HIV, see Mycobacterium avium complex (MAC) infection in adults with HIV infection for advice on starting antiretroviral therapy.
If starting treatment for M. avium complex infection in patients taking antiretroviral therapy for HIV infection, check for potential drug interactions when prescribing antibiotics (see Antiretroviral drug interactions).
Maintenance therapy (secondary prophylaxis) for disseminated Mycobacterium avium complex disease in patients with HIV infection is the same as primary treatment; two or three drugs are used according to tolerance and drug interactions. For patients on antiretroviral therapy with a suppressed HIV viral load, maintenance therapy can be stopped when the CD4 count has been more than 100 cells/microlitre for 6 months or more, and the patient has completed 12 months or more of treatment for Mycobacterium avium complex and has no residual signs or symptoms.