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Test Positive Aware Network
Norvir (Ritonavir, RTV)
January/February 2008
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Brand Name: Norvir
Common Name: ritonavir (RTV)
Class: HIV protease inhibitor (PI)
Standard Dose: Almost never used at its approved dose (a lead-in dosing, then six 100 mg soft gelatin capsules twice-a-day, preferably with food -- dose escalation is important to avoid side effects). Norvir is primarily used as a boosting agent for other PIs, at smaller doses of 100 to 400 mg, either once or twice a day. Take a missed dose as soon as possible, but do not double up on your next dose. Approved for children ages one month and older. Liquid formula available, but tastes unbelievably horrific.
AWP:$308.60/month for 30 capsules
Manufacturer contact: Abbott Laboratories,
www.norvir.com, 1 (800) 222–6885
AIDSInfo: 1 (800) HIV–0440 (448–0440), www.aidsinfo.nih.gov
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| Potential side effects and toxicity: |
Most common side effects include weakness, stomach pain, upset stomach (nausea, diarrhea, and vomiting), tingling/numbness around the mouth, hands or feet, loss of appetite, taste disturbance, weight loss, headache, dizziness, pancreatitis (see nukes), and alcohol intolerance.
As seen with other protease inhibitors, there can be increased levels of cholesterol and triglycerides (except possibly unboosted Reyataz) which may be associated with an increased risk of heart disease. Other possible side effects seen with protease inhibitors are lipodystrophy (body fat changes, including thinning of the face, arms and legs, with or without fat accumulation in the stomach, breasts and sometimes the upper back), onset of new cases or worsening of diabetes (see your doctor promptly) and increased bleeding in hemophiliacs. Immune Reconstitution Inflammatory Syndrome (IRIS) may occur as the immune system regains strength; report symptoms of illness, such as shingles and TB, to health care provider.
Other potential side effects are liver problems, such as increase in liver enzymes (AST, ALT and GGT), hepatitis, or jaundice (yellowing of skin); and increased muscle enzyme (CPK) and uric acid. People with hepatitis B or C may be at increased risk.
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| Potential drug interactions: |
Ritonavir interacts with many other drugs. See the manufacturer package insert for the most complete list. Do not take with Tambocor, Rythmol, Cordarone, Versed (midazolam), Halcion (triazolam), Uroxatral, Rifadin (rifampin), Orap (pimozide), ergot derivatives (such as Cafergot, Wigraine, Methergine, and D.H.E. 45), Antabuse (disulfiram) or Flagyl (metronidazole), garlic supplements, or the herb St. John's wort. Do not use Zocor or Mevacor; lipid-lowering alternatives are Lipitor, Lescol (fluvastatin), and Pravachol, but they should be used with caution due to potential for liver toxicity. Increases levels of fluticasone (active component of Advair, Flonase, Flovent) and trazodone (Desyrel).
Cialis, Levitra, and Viagra levels are increased; doses should not exceed 10 mg Cialis per 72 hours, 2.5 mg Levitra per 24 hours, or 25 mg Viagra per 48 hours.
The effectiveness of birth control pills may be decreased when taking Norvir; women and their male partners should consider the use of alternative contraception methods with barrier.
Levels of the street drug Ecstasy are greatly increased by Norvir, and at least one death has been attributed to the combination. GHB is also dangerous with Norvir. Tobacco and alcohol may lower blood levels of Norvir. Increases seen in Biaxin (clarithromycin) levels by 80 percent. Rifampin decreases Norvir levels by 35 percent. Contains alcohol (but should not be enough to trigger relapse), so be cautious with Antabuse (disulfiram) or Flagyl (metronidazole) -- greatly hastens intoxication.
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| Tips: |
The real strength of Norvir is in combination with other PIs (used as a boosting agent), allowing for a lower dose of both and in many cases decreasing the frequency of doses. Stomach side effects are reduced by taking Norvir with high fat foods (such as peanut butter or avocado) -- however, be careful because some other HIV medicines should not be taken with high fat foods. You can mix liquid solution in ice cream, milk or pudding to hide the taste. The capsules contain castor oil and have bitter taste. Chocolate masks the bitter taste. Blood concentration increases in people with hepatic (liver) impairment. Please see package insert for more complete potential side effects and interactions.
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| Doctor |
Norvir didn't have an auspicious beginning. You had to gradually work your way up to the full dose of 6 capsules twice a day because the side effects were so awful, but even with "dose escalation," the side effects were still awful: nausea, diarrhea, fatigue, tingling sensations, and general misery were pretty typical. We came up with all sorts of strategies to reduce the misery. I remember telling my patients about the importance of the "Three F's": food, fat, and fiber. (The drug was raising my patients' cholesterol and triglycerides, and I was telling them to eat more fat…in Baltimore, where there's no shortage of fat in the diet!) It was also a drug that had the longest list of drug interactions anyone had ever seen. In the end, though, it was the drug interactions that rescued Norvir from oblivion. It turned out that much lower and more tolerable doses of Norvir could be used to increase the drug levels of the other PIs, which made them stronger and less prone to resistance and allowed them to be taken less often or with fewer pills. That's the only legitimate use for Norvir now, and it's an important one. The only reason not to take Norvir if you're on a PI is if you're what I call a "ritonophobe": one of those rare people who can't tolerate even a single capsule. That doesn't apply to Invirase, Prezista or Aptivus, which must be boosted. And if you're still taking 600 mg twice a day, consider getting a second opinion!
The instructions on your bottle of Norvir will mention the need for refrigeration, but that's more important for storage by the pharmacist than it is for you. A month's supply doesn't have to be refrigerated; it can be kept at standard room temperature, but it shouldn't be allowed to get too hot. -- Joel Gallant, M.D. |
| Activist |
Within the first year of sales, it became clear that there was little or no use for full dose Norvir. An easier to tolerate pill version was launched in a few years, but liver and cholesterol problems also surfaced with annoying frequency. Over time, the use of the drug as a booster took prominence. Still, not everyone agrees that using Norvir as a booster is an acceptable thing. They argue that Norvir boosts many other drugs by suppressing a powerful and natural function of the liver that is intended to protect the body from a variety of harmful substances. Moreover, it creates a large and sometimes difficult to manage number of interactions with other drugs that are also affected by the action of Norvir. -- Martin Delaney |
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This article was provided by Test Positive Aware Network. It is a part of the publication Positively Aware.
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