LONG-TERM REMISSION OF HIV-1 DISEASE CAN BE READILY ACHIEVED by combinations of antiretroviral providers. of interest not only for HIV professionals as they try to optimize therapy but also for additional physicians who care for HIV-positive individuals. The introduction of highly active antiretroviral therapy (HAART) PTK787 2HCl offers led to a significant reduction in AIDS-related morbidity and mortality.1 2 3 Unfortunately up to 25% of individuals discontinue their initial HAART regimen because of treatment failure (failure to suppress HIV viral replication to below the current limit of detection 50 copies/mL) toxic effects or noncompliance within the 1st 8 weeks of therapy.4 5 Several strategies have been implemented to improve treatment duration. While development of fresh antiretroviral providers continues efforts to maximize the effectiveness of currently available treatments include attempts to better understand and manage adverse effects. Each antiretroviral medication is associated with its own specific adverse effects or may cause problems only PTK787 2HCl in particular circumstances. Similarly class-specific adverse effects may happen. One of the drug classes used in HAART is the nucleoside reverse transcriptase inhibitors (NRTIs) which generally form the “backbone” of the antiretroviral cocktail; this class includes zidovudine (AZT) lamivudine didanosine (ddI) stavudine (d4T) abacavir (ABC) and the newly released nucleotide analogue tenofovir. Two NRTIs are often combined with 1 medication from either of the 2 2 remaining classes the non- nucleoside reverse transcriptase inhibitors (NNRTIs) and the protease inhibitors (PIs). The NNRTI class comprises nevirapine (NVP) delavirdine (DLV) and efavirenz (EFV). The PTK787 2HCl dosages and adverse effects of all 3 classes of medications are outlined in Table 1. Table 1 continued Table 1 In this article we review the adverse effects of HAART therapy with specific attention to the metabolic abnormalities associated with HIV treatment including PTK787 2HCl dyslipidemias diabetes mellitus insulin resistance and the lipodystrophy syndrome and lactic acidosis associated with NRTI mitochondrial toxicity. Our goal is to help physicians gain a working knowledge of these adverse effects with the ultimate goal of improving the tolerability and performance of HIV treatment advertising the early acknowledgement and reversal of potentially serious adverse effects and reducing the potential for adverse drug relationships. Significant antiretroviral adverse effects Antiretroviral therapy can have a wide range of adverse effects on the body (Fig. 1). Common but slight adverse effects happening early in most antiretroviral regimens include gastrointestinal effects such as bloating nausea and diarrhea which may be transient or may persist throughout therapy.6 Other common nuisance adverse effects are fatigue and headache caused by AZT and nightmares associated with EFV. Several uncommon but more serious adverse effects associated with antiretroviral therapy including AZT-associated PTK787 2HCl anemia d4T-associated peripheral neuropathy PTK787 2HCl PI-associated retinoid toxicity (exemplified by pruritus and ingrown toenails) and NNRTI-associated hypersensitivity reactions are treated relating to approved therapy for these conditions in individuals not receiving HAART. However the delicate and serious nature of additional adverse effects – lactic acidosis hepatic steatosis hyperlactatemia hepatotoxicity hyperglycemia excess fat maldistribution hyperlipidemia bleeding disorders osteoporosis and pores and skin rash – warrant more detailed conversation. Fig. 1: Adverse effects of antiretroviral therapy. In some cases only a certain drug causes the Mdk effect (drug name in parentheses). Picture: Chesley Sheppard Lactic acidosis hepatic steatosis and hyperlactatemia NRTIs are nucleoside analogues that prevent DNA elongation and viral reproduction. These medicines are triphosphorylated intracellularly to become nucleotides and are then incorporated into the viral DNA chain from the viral reverse transcription enzyme; their presence in the DNA halts transcription. Regrettably these medicines can theoretically also function as substrates for additional.