CHOP is a four-drug chemotherapy regimen including cyclophosphamide (Endoxana), doxorubicin, vincristine (Oncovin) and prednisolone. It is used in the treatment of several cancers including lymphoma. Side-effects include low white blood cell counts.

Following improvements in prognosis since the introduction of combination antiretroviral therapy, HIV-positive patients taking HIV treatment now have similar outcomes to HIV-negative people when treated with CHOP for non-Hodgkin’s lymphoma^[1][2][3][4]. This is true even for patients with the aggressive diffuse large B-cell form of the disease^[5].

Patients taking CHOP may experience reduced levels of the protease inhibitors indinavir (Crixivan) or nelfinavir (Viracept), which may require monitoring of drug levels in the blood^[6].