Illicit drugs and drug interactions

Australian Pharmacist. 25 9. 684-689 2006

Angela Dean

Almost half the population of Australian adults reports use of an illicit substance at least once. Therefore it is likely that some of our patients may be using illicit drugs in combination with other medications. Illicit substance use may contribute to adverse effects, interfere with treatment efficacy, or even augment treatment effects. Additionally, regular users of illicit substances may exhibit poor medication adherence or impaired ability to engage in behaviours such as blood glucose testing in diabetes.
Systematic research on drug interactions with illicit drugs is not routinely conducted – most evidence comes from case reports. However, drug interactions are important. Many deaths that are attributed to illicit drug toxicity alone are often actually the result of drug interactions. This article reviews potential drug interactions with illicit drugs, with an emphasis on the two most popular illicit drugs in Australia – cannabis and methamphetamine.