Antiretroviral treatment (ART) suppresses viral replication at various stages in the viral lifecycle, but does not eliminate HIV and therefore treatment is lifelong. The pharmacokinetics and pharmacodynamics of these agents and their interactions with other medicines can be complex. HIV treatment regimens should meet the particular requirements of individual patients.
Choices about starting and changing ART, and which drugs to use, require prescribers to possess and integrate data on the interpretation of the genetic make-up of both the virus and the host, while at the same time assessing the ways in which antiretroviral pharmacology and drug interactions may impact on pre-existing conditions. Safe and effective prescribing of appropriate ART is crucial to maximise benefits, minimise adverse effects, avoid drug interactions and reduce the emergence of drug resistance. Good communication with well-informed and supported patients who participate in shared decision-making about treatments is an essential component of success.
Prescribing of ART should be supported by safe and effective use of clinical and laboratory monitoring of drug response, drug toxicity and treatment adherence. There is evidence that a substantial proportion of people prescribed ART are at risk of a clinically significant drug–drug interaction and this risk may increase as people age and are likely to be prescribed more drugs by different prescribers. Safeguards must be in place to minimise errors and promote good prescribing.
Robust engagement with primary care to minimise potential drug interactions is an essential aspect of good prescribing practice. Polypharmacy is increasingly recognised as an important factor in patient safety and a number of resources exist to guide healthcare professionals and patients. Recommendations from these resources inform, and are incorporated into, our quality statements below.
ART continues to represent a major component of the costs of treatment and care for people living with HIV in the UK; this means that clinically effective and cost-effective prescribing is essential to make efficient use of NHS resources. As generically manufactured antiretrovirals become increasingly available, treatment changes for reasons of cost saving are more frequent. Informed decision-making with the patient having a sense of control in this process is likely to increase the success of this strategy. The development of drug resistance and toxicity through inappropriate HIV prescribing might further increase costs so careful consideration of patient engagement and switch choice is important. Patient information and resources about generic medications are available from professional and third sector organisations.