As this is the NEW website for the AIDS Committee of Windsor, AIDS Support Chatham-Kent, and the Drouillard Road Clinic, everything is new and in the process of being updated. If by chance there is anything wrong with the information, feel free to contact us.

ddC is a type of anti-HIV drug called a nucleoside analogue reverse transcriptase inhibitor." The most common side effect of ddC is peripheral neuropathy. Other side effects include headache, oral ulcers, fatigue, nausea, abdominal pain, and diarrhea. ddC is taken 3 times daily.

ddC, also known as zalcitabine and sold under the brand name Hivid, is a nucleoside analogue reverse transcriptase inhibitor, a type of antiretroviral drug. Antiretroviral drugs fight HIV infection by interfering with the life cycle of the virus. At each stage of this cycle, chemicals called enzymes help the virus make copies of itself (replicate). Some drugs can inhibit (slow down or stop) the actions of these enzymes. When these enzymes can't perform effectively, the virus does not replicate as efficiently and this slows the progression of HIV disease.

HIV infects cells and then replicates with the help of its own enzymes. In the first stage of replication, the enzyme reverse transcriptase converts the genetic material of the virus (RNA) to match the genetic material of the cell (DNA). Nucleoside analogue reverse transcriptase inhibitors (NRTIs or "nukes") like ddC block the building of viral DNA and may also interfere directly with the action of the reverse transcriptase enzyme, preventing it from working properly.

For many people combination therapy with 3 or more anti-HIV drugs can improve CD4+ counts and viral load measures, and reduce opportunistic infections. Currently, the most popular combinations include 2 NRTIs and 1 protease inhibitor. Using NRTIs with protease inhibitors interferes with the viral life cycle at 2 different stages.

Although there is no "best" combination, it may help to consider the following points when designing an antiretroviral "cocktail".

Combinations to avoid:

• AZT + d4T or 3TC + ddC. Before they can go to work against HIV, all nucleoside analogue drugs must be broken down by enzymes inside cells. Because AZT and d4T, or 3TC and ddC need the same cellular enzyme to become active, they compete for the use of that enzyme. As a result of this competition, there may not be enough drug activated to fight HIV.
• ddC + ddI or ddC + d4T. Using these drugs together may increase the risk of developing peripheral neuropathy.

Ingredients to consider:

• 3TC, AZT, d4T, and abacavir can enter the brain. Keeping at least one of these drugs in the cocktail may help prevent the development of dementia or other neurological conditions.

The most common side effect of ddC is peripheral neuropathy (tingling, burning, or numbness, usually in the toes), reported by 17-31% of volunteers enrolled in clinical trials. Peripheral neuropathy is often a "dose-related" side effect which may go away when ddC is stopped, although it may take weeks or months for the neuropathy to improve.

Other common side effects reported in trials were headache, oral ulcers, fatigue, nausea, abdominal pain, diarrhea, vomiting, rash, itching, muscular pain, and fever.

The most serious side effect of ddC is pancreatitis, an inflammation of the pancreas, that occurred in less than 1% of trial volunteers. Symptoms of pancreatitis include severe nausea, vomiting, and abdominal pain.

Although there have been no reports of side effects unique to women, Richard Moore and colleagues reviewed the charts of 1,450 HIV-positive people and found that women reported fewer side effects with ddC than did men, although the difference was not statistically significant.

Combining ddC with other drugs that can cause either peripheral neuropathy (for example ddI, d4T, or some anti-cancer drugs) or pancreatitis (alcohol, IV pentamidine) may increase the risk of developing those side effects.

The recommended dose of ddC is 0.75 mg taken 3 times a day, preferably without food.

ddC is available with a prescription. It is covered by all provincial drug formularies.

Because HIV can infect brain cells, it's important to consider a drug's ability to reach the brain when putting together an anti-HIV regimen. It's probably wise to include at least one drug that has been shown to cross the blood-brain barrier to some useful degree as part of your regimen. These include AZT (zidovudine, Retrovir), d4T (stavudine, Zerit), abacavir (Ziagen), nevirapine (Viramune), amprenavir (Agenerase) and to a lesser degree indinavir (Crixivan) and 3TC (lamivudine, Epivir). Efavirenz (Sustiva) has not been shown to cross the barrier to a significant degree, but some experts speculate that it might have some useful effect in impacting HIV in the spinal fluid.