Dapsone is an approved oral antibiotic drug. It can be used in combination with trimethoprim for treating Pneumocystis pneumonia (PCP), and may be used as PCP prophylaxis for people who cannot tolerate cotrimoxazole (Septrin).1 It is often used in combination with pyrimethamine (Daraprim) to prevent of toxoplasmosis and PCP, since these two drugs enhance each other’s activity.2 GlaxoSmithKline manufactures a combination of these two drugs in one tablet under the trade name Maloprim.

Dapsone with pyrimethamine also reduces the incidence of Mycobacterium avium intracellulare and tuberculosis.3

Dapsone remains at a high level in the body for a long time after each dose is taken, so weekly or twice weekly dosing may thus be justified, although this dosing is controversial.4 It is best taken with food to avoid nausea. Once-weekly dosing produces adequate drug levels in HIV-positive children, although daily dosing may be more effective in preventing PCP.5 6

Dapsone causes a relatively high rate of allergic skin rashes.7 Other side-effects include nausea and blood disorders. A comparative study of dapsone and atovaquone (Wellvone) for the prevention of PCP found that among people who were not previously on dapsone, atovaquone caused fewer side-effects.8

The absorption of dapsone may be reduced if the level of acid in the stomach is below normal. This may happen in people who have low levels of acid in the stomach or if it is taken at the same time as the anti-HIV drug ddI (didanosine, Videx / VidexEC), which includes an antacid in its formulation. People taking both dapsone and ddI should take the dapsone at least two hours before or after the ddI.


  1. Saillourglenisson F et al. Effet de la dapsone sur la survie des patients infectés par le VIH: une métaanalyse des essais terminés. Rev Epidemiol Sante Publique 48: 17-30, 2000
  2. Opravil M et al. Once-weekly administration of dapsone-pyrimethamine vs. aerosolized pentamidine as combined prophylaxis for Pneumocystis carinii pneumonia and toxoplasmic encephalitis in human immunodeficiency virus-infected patients. Clin Infect Dis 20: 531-541, 1995
  3. Opravil M et al. Dapsone-pyrimethamine (DP) might prevent mycobacterial disease in HIV infection. Clin Infect Dis 20: 244-249, 1995
  4. Cruciani M et al. Twice-weekly dapsone for primary prophylaxis against Pneumocystis carinii pneumonia in HIV-1 infection: efficacy, safety and pharmacokinetic data. Clin Microbiol Infect 2: 30-35, 1996
  5. Mirochnick M et al. Pharmacokinetics of dapsone administered daily and weekly in human immunodeficiency virus-infected children. Antimicrob Agents Chemother 43: 2586-2591, 1999
  6. McIntosh K et al. Toxicity and efficacy of daily vs. weekly dapsone for prevention of Pneumocyctis carinii pneumonia in children infected with human immunodeficiency virus. ACTG 179 Study Team. AIDS Clinical Trials Group. Pediatr Infect Dis J 18: 432-439, 1999
  7. Coopman SA et al. Cutaneous disease and drug reactions in HIV infection. N Engl J Med 328: 1670-1674, 1993
  8. El-Sadr W et al. Atovaquone compared with dapsone in the prevention of Pneumocystis carinii pneumonia in patients with HIV infection who cannot tolerate trimethoprim, sulphonamides, or both. N Engl J Med 339: 1889-1895, 1998

Community Consensus Statement on Access to HIV Treatment and its Use for Prevention

Together, we can make it happen

We can end HIV soon if people have equal access to HIV drugs as treatment and as PrEP, and have free choice over whether to take them.

Launched today, the Community Consensus Statement is a basic set of principles aimed at making sure that happens.

The Community Consensus Statement is a joint initiative of AVAC, EATG, MSMGF, GNP+, HIV i-Base, the International HIV/AIDS Alliance, ITPC and NAM/aidsmap

This content was checked for accuracy at the time it was written. It may have been superseded by more recent developments. NAM recommends checking whether this is the most current information when making decisions that may affect your health.

NAM’s information is intended to support, rather than replace, consultation with a healthcare professional. Talk to your doctor or another member of your healthcare team for advice tailored to your situation.