people with HIV need to take medicines to treat other health conditions. Taking
two or more different drugs together may result in an alteration in the
effectiveness or in the side-effects of one or more of the drugs. Some drugs
should not be taken in combination with certain antiretrovirals.
is important that anyone prescribing or dispensing medication knows about all
other medicines and drugs that you are taking – this includes those prescribed
by another doctor, over-the-counter medicines (including inhalers and nasal
sprays), herbal and alternative treatments, and recreational drugs.
drug combinations are contraindicated – which means you definitely should not
take them together. Reasons for this include serious side-effects,
or interactions which make one or both drugs ineffective or toxic.
interactions are less dangerous, but still need to be taken seriously. Levels
of one or both drugs in your blood may be affected and you may need to change
the doses you take.
HIV doctor and pharmacist will check for possible interactions before they
prescribe a new drug for you.
any other healthcare professional prescribes or recommends a medicine for you,
it’s important that they know about the drugs you are taking for your HIV. For
example, it’s known that treatments for erectile dysfunction (such as Viagra) can interact with types of
anti-HIV drugs that belong to the drug classes protease inhibitors (PIs) and
non-nucleoside reverse transcriptase inhibitors (NNRTIs). Interactions with
protease inhibitors can increase blood levels of Viagra and similar drugs, increasing the risk of side-effects.
also need to tell your HIV doctor about any drugs you buy over the counter (at
a chemist, for example) or from the internet. Some anti-HIV drugs can interact
with antihistamines, asthma inhalers or nasal sprays (which contain steroids), treatments
for indigestion and statins (drugs that are used to control cholesterol, or
lipid levels). These treatments can either be prescribed or bought over the
counter at high-street chemists (community pharmacies).
you are thinking of using any other drugs, you should tell your HIV doctor or
pharmacist so they can check for possible interactions and recommend the most
suitable treatment. Or, when you are buying them, you may wish to tell the
pharmacist about the anti-HIV drugs you are taking. Community pharmacies often
have a private area for consultations, or you could write the name of the drugs
down and hand them to him or her. If you do need to mention the name of your
anti-HIV drugs, it’s very unlikely that anyone around you will recognise what
they are used to treat.
is known about interactions with recreational drugs. But there are potential
interactions between some recreational drugs (for example, ketamine, ecstasy
and methamphetamine [crystal meth]) and some NNRTIs and PIs. If you use
recreational drugs, it is sensible to discuss this with your doctor, HIV
pharmacist or other healthcare provider.
drugs can also interact with herbal and alternative treatments.
example, St John’s
wort, a herbal remedy used to treat anxiety and depression, lowers blood levels
of NNRTIs and PIs. It can cause them not to work effectively and there’s a risk
of developing resistance.
In many cases, the interactions are theoretical, or seen in test-tube
studies, and more information is needed about the likelihood of a real-life
effect. For example, test-tube studies have indicated that African potato and Sutherlandia
may reduce levels of PIs, NNRTIs and maraviroc (Celsentri) in the body.
can also happen with medicines that are not taken by mouth. For example,
ritonavir and cobicistat can interact with inhalers and nasal sprays containing
fluticasone, budesonide, mometasone, or salmeterol (e.g. Flixotide,
Flixonase, Pulmicort, Seretide,
Serevent, Nasonex, Pirinase), used to treat asthma and hay
fever, potentially causing serious side-effects. Cetirizine (Piriteze, Benadryl One-A-Day,
Zirtek and Pollenshield)
is a safe antihistamine to take with anti-HIV drugs and can be bought over the
counter or prescribed by your GP.
can safely take some painkillers, such as paracetamol, when on anti-HIV drugs,
unless there are other medical reasons why you shouldn’t take this sort of
drug. Check with your HIV doctor or pharmacist about the best type of
painkiller for you.
can find out more about possible interactions with individual drugs in NAM’s
booklet Anti-HIV drugs.
sure you tell your clinic doctor and HIV pharmacist about all the
medicines you are taking. This includes prescribed medicines, medicines you buy
from a chemist, herbal or traditional medicines, and recreational drugs. It’s
important to check about possible interactions before taking anything new
(whether you buy it yourself or have it prescribed by a doctor or