Pharmacology of drugs for HIV

There are now some 22 drugs available in the UK which can be used in the treatment of HIV infection. Most are given in combination to delay the onset of drug resistance and to improve patient adherence to an often complex regimen. Six combinations of these drugs are also currently available in fixed-dose preparations. The 22 drugs fall into six main categories which act either to prevent the HIV virion from entering the human T cell or to prevent its incorporation into the cellular structure. Apart from drug resistance and poor patient adherence, the other main problem is a multiplicity of possible drug–drug interactions, not only between anti-HIV drugs but with other co-administered agents. This article gives a brief account of the pharmacology of these drugs, emphasizing emerging topics in the field.