Not taking your HIV medications properly can mean that they do not work effectively, leading to an increase in your viral load, a fall in your CD4 cell count and a greater risk of becoming ill and even dying because of HIV.

The reason adherence is so important is because HIV can quickly become resistant to the drugs used to treat it. If the blood level of an anti-HIV drug drops too low, then it will be unable to stop HIV reproducing and this gives the virus an opportunity to develop resistance. The drug-resistant strains of the virus will become dominant.

This could mean that not only do you become resistant to the drugs you are currently taking, but also to drugs similar to these. For example, if you develop resistance to one of the approved non-nucleoside reverse transcriptase inhibitor (NNRTI), you’re likely to become resistant to the other licensed  NNRTIs. This is called cross-resistance, and although the risk varies from drug to drug, cross-resistance can occur in all classes of drug used to treat HIV.

Adherence is so important that many doctors think it is better to stop treatment altogether rather than miss doses. However, this carries its own risks, and if you are finding it difficult to take your medication and think that you need a break from your treatment, discuss the pros and cons with your doctor.