Coping with side-effects

The possibility of side-effects is something each patient needs to consider before choosing to be treated with antiretroviral drugs and when selecting a treatment regimen. Medical history, along with co-existing morbidities and current medications, can influence the choice of drugs included in a regimen, so as not to increase the likelihood of particular side-effects.

It is especially difficult for someone who is feeling healthy to start a daily treatment regimen that may help lower viral load, but negatively affect daily quality of life. Each person should weigh the potential benefits of treatment against the drawbacks. This can best be done through open and candid discussion between patient and clinician and by sharing as much information as possible about treatment regimens and their effects.

With HAART, there are drugs from at least five different drug classes used and it can be difficult to identify the medication causing the problems, especially if someone is on a regimen with drugs that cause similar side-effects or that may be interacting in complex ways. On the other hand, some side-effects are characteristic of certain drugs. Tenofovir or indinavir are known to cause kidney problems and AZT commonly causes anaemia. If viral load is undetectable and the side-effect is characteristic of one particular drug, it is usually possible to change the one drug without changing the entire HAART regimen.

Therapeutic drug monitoring is a very useful tool that can determine whether there is an appropriate amount of a particular drug in the bloodstream. If the problem is not being caused by a drug level that is too high or too low, then you would want to change to another drug with a more favourable side-effect profile. Unfortunately, the option of pharmacokinetic testing (PK) is not always available.

Management of side-effects depends on their nature. Some can be managed through use of an additional medication, as may be the case with headache or mild diarrhoea, and other side-effects may just subside with repeated drug exposure. Some side-effects develop over time, causing or exacerbating other medical issues, such as metabolic changes or elevated cardiovascular risk. A change in regimen may help in limiting or avoiding these problems. Some side-effects are severe enough to warrant immediately stopping the offending drug, as is the case with Stevens-Johnson syndrome or lactic acidosis.

Since drug resistance can quickly develop with missed doses, the relationship of adherence to both virological success and maintaining subsequent treatment options should be understood before starting a regimen. In cases where the side-effects are manageable, it is best to stay on all drugs in a regimen until a course of action is decided.