What Is Ribavirin?
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Ribavirin was one of the first antiviral drugs ever discovered. It is approved in the United States in an aerosol form for the treatment of a severe lung infection (RSV) in infants. It is being studied in combination with ddI as an anti-HIV treatment. More recently, it has shown activity against hepatitis A, C and B. Ribavirin is available in numerous countries in an oral, tablet form. The PWA Health Group helps people import ribavirin from Mexico.
Ribavirin in AIDS
Since the beginning of the AIDS crisis, people have tried ribavirin as an anti-HIV treatment. Part of the early enthusiasm was because in the test tube, ribavirin inhibits HIV. However many people were also misled by false claims made for the drug by it’s sleazy, former manufacturer, ICN Pharmaceuticals.
Ribavirin is now owned by Schering-Plough, who owns one of the alpha-interferons (Intron-A) on the market. This is a welcome development, because they have the means to bring ribavirin to market. They’re betting on it, or they wouldn’t have bought it. What’s bad is that they closed all compassionate use for the drug, which given its price is unconscionable.
Ribavirin to fight HIV
Ribavirin Used Alone
Several controlled studies have shown that ribavirin is not effective against HIV. It has no effect on T4 cells, T8 cells, p24 antigen, etc. A meta-analysis of the four largest studies showed a significant effect on delaying progression. These studies were done before viral load testing was available, so it’s hard to say how real this information is. In the test tube, ribavirin cancels out AZT, but increases the activity of ddI.
Ribavirin combined with ddI
Ribavirin increased the effect of ddI ten-fold in vitro. In an animal model, neither ribavirin nor ddI alone affected tumour growth. When combined, they significantlydelayed progression. We don’t know why; perhaps ribavirin changes the intracellular environment of ddI’s target cells.
A small ACTG study of a ribavirin/ddI combo indicated that it was safe, and that it had a slightly greater effect on HIV viral load than ddI alone. They are now planning a follow-up study in kids. Why kids? Maybe because it’s safe and already been studied in kids.
Hepatitis C
Hepatitis C is a viral infection of the liver. It’s often chronic, and can lead to cirrhosis and liver cancer. It’s difficult to treat, and harder to cure. Diagnosis is based on the antibodies your body produces in response to hepatitis C infection, liver biopsy, and/or a PCR test that directly measures the hep C viral activity in your blood. You can be a carrier, or have a persistent infection. When to treat and the best way to treat hepatitis C is not yet known.
Treating Hepatitis C
Bringing your liver enzymes down as close to normal as possible will reduce liver damage. Researchers aim to eradicate the hep C virus, but don’t forget that even lower enzymes are a good result. You’ll know, because your energy level will improve. Hepatitis C is not well understood. There are six subtypes of hep C, plus variations, all of which may respond to treatments differently. Check out new trial regimens and watch your enzymes.
Alpha-interferon is the standard treatment for hepatitis C. There are two kinds on the market. It’s given subcutaneously, at 3MU 3x a week, for 6 months. 10-30% of people respond (liver enzymes down to normal). It’s hard to take. Side effects include: severe nausea, fever, diarrhea, flu-like everything, etc.. One small study suggests that 6MU 3x a week for 12 months, may lower enzymes in more people (76%), and keep them down after a year of follow-up (49%). For most people, liver enzymes returm to pre-treatment levels after stopping alpha-interferon. Sometimes after a full treatment of alpha-interferon, liver enzymes bounce higher than they’ve ever been. They usually return to pre-treatment levels, 3-5 months later.
There are different kinds of interferons coming on the market soom, such as Alferon and Welferon. These are not recombinant products. They may cause fewer sider effects.
Of note, several small hepatitis C studies combining thymosin-alpha with alpha-interferon have reported undetectable viral loads and sustained enzyme drops. Call us for more info and copies of the studies.
Ribavirin for Hepatitis C
Ribavirin alone promptly brings down liver enzymes, but they often bounce right back up within weeks of stopping ribavirin. In one controlled study of 32 people, 4/16 on ribavirin 1200 mg/day had mornalized liver enzymes, and 7/16 had a 50% decrease in enzymes. In another controlled study, 10/29 had normal liver enyzmes on ribavirin, but after stopping treatment, this number fell to 2. Several studies report significant drops in liver enzymes, but little or no change in hepatitis C viral load. Ribavirin may suppress viral replication, but does not appear to eradicate the virus.
Combining ribavirin and alpha-interferon looks very promising. Schering Plough is running clinical trials offering 1200mg/day of ribavirin plus 3 MU Intron-A 3x/week. Several studies of this combination have shown sustained enzyme and viral load drops in significant numbers of participants, even after stopping treatment. In a study of 20 people on either interferon or interferon/ribavirin, 40% of the combo group had normal liver enzymes at 96 weeks after a 6 months course of the combo.
Ribavirin in Hepatitis A & B
A placebo-controlled Serbian study in 57 people with acute hepatitis A reported that ribavirin (800 mg/day) lowered enzymes faster and more than those on placebo. The study could find no therapeutic effect from ribavirin in 28 patients with acute hepatitis B.
Japanese researchers compared ribavirin (800-1000mg/day) to ribavirin/beta-interferon (3 MU 3x/week) to beta-interferon, for three months in 24 people with hepatitis B. Ribavirin and the combo “lowered hep B blood levels in most people.” In a 6-9 month follow-up, one person on ribavirin, two on beta-interferon and two on the combo cleared hep B virus. Finally, in one study, ribavirin had no effect on hepatitis D.
Dosing
There is no clear information about the best dose. Doses over 1200 mg/day appear to be toxic, causing transient anemia. The ACTG ddI combo study offered 600mg/day of ribavirin. For hepatitis C, 1200 mg/day (in three doses) is most common. Note: some researchers believe that treatment for a full year is required to clear the hep C virus.
Side Effects and Toxicity
Ribavirin can cause anemia and drops in T cells when given at doses of 1200-1600 mg per day. This anemia is not permanent, and ends quickly if you take less, or stop d\taking the drug. At 800 mg per day, ribavirin does not seem to cause anemia. Otherwise, in general ribavirin seems to be easily tolerated.
In the hepatitis C studies, temporary dose reductions to 800 mg/day were common for those who became anemic.
Long term use of ribavirin may lead to a build up of iron in the liver, which could be harmful. Check with your doctor.
