Antiretroviral drugs for HIV

Antiretroviral drugs
Antiretroviral drugs are used to treat HIV (human immunodeficiency virus) infection; some are also effective against and used to treat hepatitis B infection.

Currently the different classes of drugs include: Nucleos(t)ide Reverse Transcriptase Inhibitors, Non-Nucleoside Reverse Transcriptase Inhibitors, Protease Inhibitors, Fusion Inhibitors, Integrase Inhibitors, Cell Entry Inhibitors and Interferons.

Background
Monitoring the safety of antiretroviral drugs is a difficult area. Patients who take these drugs are usually receiving combination therapy for HIV or hepatitis B or both infections. Patients, especially those with HIV may, at times, be taking drugs for conditions associated with their infection. In addition as HIV becomes a long-term condition they may be taking medicines for unrelated conditions. HIV itself can also lead to numerous illnesses such as opportunistic infections and certain cancers.

As a result it can be extremely difficult to decide if a particular event is due to the illness itself or a drug side-effect, and in which case which drug? In addition many of the drugs used to treat these conditions interact with other drugs and an adverse reaction may result from this.

This picture is made all the more difficult by the long-term nature of treatment. As people with HIV increasingly live much longer new problems arise. Often it is difficult to tell whether these are the result of HIV, side-effects of medications or age.

Similarly for patients with hepatitis B treatment regimens are changing and the long term effects are as yet unknown.

How we use the information provided on Yellow Cards
We use Yellow Card data to detect ‘signals’ of adverse events associated with drugs. A signal can be a new potential side-effect, or an increase in frequency or severity of a known side-effect. Generally, to detect these signals several reports of the same event with the same drug or drug class are needed. The more reports we receive the easier it is to study what is actually causing a problem. Thus even if someone is taking combination therapy, a particular drug can still be associated with an event or side-effect if we receive enough reports to assess it fully.

Yellow Card reports can also be used to determine whether particular people have high risk factors for side-effects and whether side-effects are reversible with or without treatment.

By reporting suspected medication side-effects through the Yellow Card system you can help to make the medicines as safe as possible.

Useful information to include on a Yellow Card for an antiretroviral drug
In addition to the basic information included on a Yellow Card report (see www.yellowcard.gov.uk) it is very helpful for our assessment of these reports to know the following:

For patients with HIV

• CD4 count now
• Lowest ever CD4 count with date if possible
• CD4 count at therapy start
• HIV viral load with date if possible
• Test results relevant to the possible side-effect (including baseline values)
• Drug-resistance profile
• Previous illnesses - both HIV related and other
• Previous side-effects
• Previous medications

For patients with hepatitis B

• Viral load with a date if possible
• Disease stage (if known)
• Degree of liver impairment
• Drug resistance profile
• Previous side-effects
• Previous medications

This is a lot of information - if you do not know it all your report will still be valuable.

What happens to the information?
If a signal is detected and further investigation shows that a possible new side-effect has been discovered or an increase in the severity or frequency of a known adverse event, then the product information for that drug will be updated. Updates are posted on the websites of the Electronic Medicines Compendium (external link) and the European Medicines Agency (external link). Major safety issues are also included in Drug Safety Update.

Please report anything you consider to be unusual or different. You do not need to believe that the drug has caused the adverse effect to report the experience using a Yellow Card.

For Yellow Card reports submitted by a healthcare professional the patient details are anonymised.

We ask for personal information such as contact details on Yellow Card reports completed by patients and members of the public. We ask for these details so that we can get in touch if more information on the Yellow Card report is needed. The information provided is kept safe, secure and confidential. To meet our responsibilities for monitoring medicines safety, the MHRA regularly publishes pooled anonymised data on the Yellow Card reports that we have received: this cannot be used to identify individual cases. Your personal data will not be passed to any person outside the MHRA without your express permission.
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