Chloroquine (Avloclor / Malarivon / Nivaquine) is an anti-malaria drug, which some experts have advocated as a low-cost treatment for HIV for use in developing countries.

Chloroquine is available as a generic formulation, or as Avloclor (AstraZeneca) and Nivaquine (Beacon).

Chloroquine may cause gastrointestinal problems, headache, convulsions, visual disturbances, loss of pigmentation, hair loss and rash. People with pre-existing liver or kidney damage should use the drug with caution. Bone marrow suppression is a rare side-effect of chloroquine which may have implications for its use in people with HIV, particularly those taking AZT (zidovudine, Retrovir), which can have the same side-effect.

Chloroquine may also have modest ant-HIV activity. It is thought to work against HIV by interfering with gp120 on the surface of HIV, inhibiting the maturation of new virus particles. It reduces the infectivity of new viruses and inhibits the ability of infected cells to clump together^[1].

Chloroquine can enhance the activity of other anti-HIV drugs, including nucleoside reverse transcriptase inhibitors (NRTIs) and protease inhibitors, by reducing the activity of drug transporters, molecules in the cell membrane that pump drugs out of cells, such as poly-glycoprotein^[2].

Test tube studies have also shown that the combination of chloroquine also enhances the anti-HIV activity of hydroxycarbamide (Hydrea) and ddI (didanosine, Videx / VidexEC), while two short-term studies of chloroquine have found that it reduces viral load to a similar degree to AZT monotherapy^[3][4][5]. A three-year study of the combination of chloroquine, hydroxycarbamide and ddI in HIV-positive patients has found it to be effective in reducing viral loads, possibly enabling the start of antiretroviral therapy to be delayed in resource-limited settings^[6].

Chloroquine use is also linked to reduced HIV viral loads in breastmilk, potentially reducing the risk of HIV transmission through breastfeeding^[7].