Types of anti-retroviral drugs.
Internationally there are many drugs available to fight HIV—some of them in combination pills. The number of generic versions available in Africa continues to grow, whilst drug companies are starting to work together to bring many existing drugs onto the market as combination pills. Drugs are divided into three classes and may have two to three different names:
- A generic name: The name of the drug whether it is made by one drug company or another
- An abbreviated name
- A brand name: The name specific to that particular company.
We can understand this by reference to chocolate. Chocolate is a generic name for a type of food. Nestle or Cadbury are brand names. On the container, the drug is normally identified by the brand name, since this is what the drug companies want us to remember. It is their Product ID. The generic name will normally appear elsewhere. For example, Zerit is a brand name and elsewhere Stavudine will be used. This can be difficult for patients who may receive different brands of the same drugs from month to month because of availability problems. It is therefore important that the patient realises that whatever brand they are given, the drugs are basically the same and offer the same standards of purity and efficacy. Some medical aids promote the use of generic drugs, as they are normally less expensive.
|Emtricitabine (on expanded access programme from Gilead)||FTC|
|Zidovudine*||AZT or ZDV|
|Tenofovir DF (on expanded access programme from Gilead)||TDF|
Africa still has a limited number of drugs available - mainly due to the fact that many of the new drugs have not been approved for local use. However, the existing numbers of drugs represent a powerful arsenal of tools to use to fight HIV.
There are currently four groups of drugs used to fight HIV:
- Nucleoside reverse transcriptase inhibitors (also known as NRTIs or Nukes)
- Non-Nucleoside reverse transcriptase inhibitors (also known as NNRTIs or non-Nukes)
- Protease inhibitors (also known as Proteases or PIs)
- Entry fusion inhibitors (also known as Fusion Inhibitors or EIs)
The last group is not yet available in Africa but the other three groups are commonly used to fight HIV.
The targets of the drugs are the three enzymes used by HIV in the multiplication process. These enzymes are:
- Reverse transcriptase
- Integrase (not yet targeted by currently available drugs)
The nukes and non-nukes target reverse transcriptase (in different ways) and protease is targeted by the proteases. By interfering with the lifecycle of HIV, viral replication is unable to continue and new viral particles are not produced.
Currently available drugs in Africa are listed below (brand names have been omitted as different brands may be available in different countries). Not all drugs will be available throughout Africa—common ones are highlighted with an asterisk (*):
|Saquinavir* (soft gel cap)||SQV (SGC)|
|Saquinavir* (hard gel cap)||SQV (HGC)|