RescriptorŽ
(delavirdine, DLV)

WHAT IS DELAVIRDINE?

Delavirdine is a drug used for antiviral therapy. It is also called RescriptorŽ. Pharmacia & Upjohn developed it. Agouron Pharmaceuticals, a Pfizer company, is marketing it.

Delavirdine is a non-nucleoside reverse transcriptase inhibitor (a "non-nuke" or NNRTI). These drugs stop HIV from multiplying by preventing the reverse transcriptase enzyme from working. This enzyme changes HIV's genetic material (RNA) into DNA. This has to occur before HIV's genetic code gets combined with an infected cell's genetic codes.

WHO SHOULD TAKE IT? Delavirdine was approved in 1997 as an antiviral drug for people with HIV infection. The safety and effectiveness of delavirdine have not been shown for people younger than 16 years old. There are no absolute rules about when to start antiviral drugs. You and your doctor should consider your T-cell count, your viral load, any symptoms you are having, and your attitude about taking HIV medications. If you take delavirdine with other antiviral drugs, you can reduce your viral load to extremely low levels, and increase your T-cell counts. This should mean staying healthier longer. WHAT ABOUT DRUG RESISTANCE? Many new copies of HIV are mutations. They are slightly different from the original virus. Some mutations can keep multiplying even when you are taking an antiviral drug. When this happens, the drug will stop working. This is called "developing resistance" to the drug. Sometimes, if your virus develops resistance to one drug, it will also have resistance to other antiviral drugs. This is called "cross-resistance". Cross-resistance among NNRTIs develops very easily. If you develop resistance to one NNRTI, you probably won't be able to use any of them in your antiviral therapy. Resistance can develop quickly. It is very important to take antiviral medications according to instructions, on schedule, and not to skip or reduce doses. HOW IS IT TAKEN? Delavirdine is available in pills of 100 milligrams (mg) or 200 mg. The recommended dose for adults is 400 mg three times a day. This would be a daily total of 6 of the 200 mg pills, or 12 of the 100 mg pills. You can dissolve the 100 mg pills (but not the 200 mg pills) in water to make them easier to swallow. Delavirdine can be taken with or without food. WHAT ARE THE SIDE EFFECTS? When you start any antiviral treatment, you may have temporary side effects such as headaches, high blood pressure, or just feeling ill. These side effects usually get better or disappear over time. The most common side effect is a skin rash, which develops in about 25 percent of people taking the drug. The risk of the rash can be reduced if you start taking the drug at a lower dose and then increase to the full dose. DOES IT REACT WITH OTHER DRUGS? Delavirdine is broken down by the liver and can interact with other drugs that also use the liver. Combining these drugs can change the amount of each drug in your bloodstream and cause an under- or overdose. Drugs to watch out for include drugs to treat tuberculosis, several antihistamines, sedatives, and anti-fungal drugs. Make sure that your doctor knows about ALL drugs you are taking. Blood levels of delavirdine may be decreased by ddI, antacids, rifabutin, and rifampin. Be sure to take delavirdine at least one hour apart from ddI or antacids. Delavirdine makes the liver work slower. This increases the blood levels of most protease inhibitors. There is very little specific information about combining delavirdine with protease inhibitors.