Why do side effects occur?

All drugs and complementary therapies [1]A broad range of healing philosophies, approaches, and therapies that Western (conventional) medicine does not commonly use to promote well-being or treat health conditions. Examples include acupuncture, herbs, Traditional Chinese Medicine, etc. have the potential for both desired (or therapeutic) effects and undesired or side effects. Some antiviral [2]A medication or substance which is active against one or more viruses. May include anti-HIV drugs, but these are more accurately termed antiretrovirals. drugs cause side effects rarely. For others, side effects may be very common. Side effects can vary in severity from very mild problems that most people have little trouble managing, to severe and sometimes life-threatening complications. Before HIV drugs are approved for use, the drug companies must show that any side effects the drugs cause are either mild enough, or rare enough that the benefit to the patient outweighs the problems associated with side effects.

Not all the physical symptoms you experience will be side effects. Many of the symptoms listed in this book can happen to anybody, regardless of HIV status. They could be caused by other health problems such as poor nutrition, injury, infections and even growing older or just plain bad luck. They could also be the side effects of HIV antiviral drugs. Identifying the cause of any physical symptom—whether it’s a side effect or not—is the first step towards controlling it.

Side effects often occur in the first two to eight weeks after starting a new treatment, after which time they gradually go away. These are known as induction side effects. Sometimes the side effects can continue past this initial period. They are then called chronic or persistent side effects. Other side effects only arise after you have been taking treatments for a long period of time. These are called long-term toxicities or long-term side effects.

Because everybody is different and everybody reacts differently to having HIV, taking treatments and using complementary therapies, it’s impossible to predict who will experience side effects and who won’t. However, most people who take HIV treatments experience some side effects.

Sometimes one symptom can have more than one cause. Diarrhoea, for instance, can be a symptom of non-HIV-related illnesses such as irritable bowel syndrome (IBS) or viral hepatitis, infection with parasites such as Giardia, dietary and metabolic problems such as lactose intolerance, or HIV-related opportunistic infections such as Mycobacterium Avium Complex (MAC). Diarrhoea is also one of the most common side effects of HIV antiviral drugs.

Sometimes the levels of the drugs you use to treat HIV might be too high, resulting in side effects. A test known as Therapeutic Drug Monitoring is available from some doctors to test the level of drugs in your body. Ask your doctor if this test might assist you.

Many of the long-term side effects associated with current HIV treatments such as lipodystrophy, lipoatrophy and changes in blood fats [3]A type of fat in the blood. Elevated triglyceride levels may be a side effect of some anti-HIV drugs. have other ‘lifestyle’ risk factors such as smoking, poor diet and lack of exercise. The increased life expectancy that many people taking combinations of HIV antiviral drugs can look forward to also means there is potentially more long-term reward from a renewed attention to a healthy lifestyle.