Antiretroviral drug resistance: A guide for the southern African clinician

Abstract

Both private and public sector see a bewildering clinical array of patients taking failing antiretroviral (ARV) regimens. We intend this article to provide a practical guide to help clinicians understand and manage ARV drug resistance in an African context. ARV resistance is a rapidly evolving field, requiring expertise in dealing with a wide range of situations. Much of the information we have on ARV resistance is from populations in the developed world where clade B is the biggest problem, while in most of Africa clade C is the commonest infection. Southern Africa is faced with the daunting prospect of putting several hundred thousand people on ARV therapy (ART) in the next few years.1 ART is the only effective option available to people with advanced HIV disease, and is remarkably effective in improving quality of life, increasing lifespan, dramatically decreasing the burden of opportunistic disease, and returning people to productive life.2
The levels of adherence demanded by ARV regimens are extremely high relative to any other chronic disease. The South African government\'s Comprehensive Care for HIV/AIDS in the Public Health Sector3,4 programme has a \'second-line\' ARV regimen (Fig. 1), specifically as a safety net for people failing the first-line regimen. Other countries do not have this luxury. The SA second-line regimen is more difficult to take, has greater toxicity, and is more expensive than the first-line treatment. ARV resistance often compromises future treatment options. The choice of regimens in the SA programme maximises the use of available drugs in this country. Our experience of private practitioners in South Africa is that they use a range of drug regimens other than those recommended in the government guidelines. There is no effective mechanism to enforce use of the government\'s recommended drug regimens, but we feel that they are the most rational use of drugs currently available in SA and that deviation from guidelines in routine use should be discouraged, unless alternative options exist. AZT/3TC is still a popular combination, and there are excellent data to support its use as the nucleoside reverse transcriptase inhibitor (NRTI) backbone in first-line therapy, but the alternatives available when resistance to this option develops (i.e. d4T with ddI) are very toxic. In other countries, alternative regimens may be more appropriate.
While we have focused on adult ARV choices in this article, the same principles generally hold for children, although choice of drugs is currently different. Again, we recommend the use of the SA guidelines, published in the November 2005 Journal.

Southern African Journal of HIV Medicine Vol. 7 (1) 2006: pp. 30-36