When one drug is taken with another, their interaction may
lower or heighten the effectiveness and/or side-effects of either one or
both drugs. This is the case both for prescribed medicines and illicit,
recreational drugs. However there is generally much less medical research on
drug interactions with illicit drugs.
There have been concerns about interactions between
antiretrovirals and recreational drugs for a number of years but recently, as new drugs like cobicistat have been introduced, the pattern of recreational drug
use among gay men living with HIV in the UK has been changing too. Crystal meth and
mephedrone are far more popular than they were in the past and are increasingly
used in the context of ‘chemsex’ in private homes. This may involve using
several substances at the same time and often for an extended period of time.
Furthermore, some men now inject recreational drugs, which
by increasing the concentration of the drug rapidly absorbed into the
bloodstream, increases the potential for adverse events.
A group including clinicians, pharmacologists, a pharmacist
and a drugs adviser has conducted a literature review and pooled expert
opinion in order to provide an up-to-date summary of the evidence on drug
interactions. Rather than covering all interactions that are theoretically possible,
they wanted their review to be practical and to guide clinicians on the
interactions that, in their own words, “really matter”. They focus on the ‘party drugs’ that are
commonly used by gay men living with HIV in the UK.
“Data on the interaction between substances of abuse and
antiretrovirals are scarce, but knowledge of the potential clinical
implications of such interactions may be of great importance for HIV care
providers,” they say.