July 1998

Dear Health Care Provider:

Abbott Laboratories is experiencing manufacturing difficulties with the capsule formulation of our HIV protease inhibitor, Norvir (ritonavir), which will result in a shortage of capsules. We have encountered an undesired formation of a Norvir crystalline structure that affects how the capsule form of Norvir dissolves. It is our plan to supply Norvir oral solution (liquid) to provide continued Norvir therapy for patients. Norvir capsules currently in distribution are not affected by this issue. When used in accordance with the prescribing information, product on the market is safe and effective.

The active ingredients in Norvir liquid and Norvir capsules are identical, as is their activity against HIV. Changing to Norvir liquid should not affect a patient’s anti-retroviral regimen.

Each Norvir capsule contains 100 mg of active drug, and each mL of Norvir liquid contains 80 mg of active drug. For patient convenience, Norvir liquid comes with a dosing cup that provides markings indicating the amount of liquid to be taken for dosages of 600 mg and 400 mg. It is important to measure the correct dose of Norvir; therefore, the dosing cup has been specially designed to provide the right dose of Norvir liquid. This cup should be used to measure a dose. Patients should wash the dosing cup with soap and warm water as soon as possible. The dosing cup is not dishwasher safe.

To facilitate your discussion with patients, we have enclosed a dosing guide that provides capsule-to-liquid conversion information. The following conversion equation may also be helpful:

6 - Norvir capsules (100 mg each) = 7.5 mL of Norvir liquid (1 1/2 teaspoons)
4 - Norvir capsules (100 mg each) = 5 mL of Norvir liquid (1 teaspoon)

Patients may improve the taste of Norvir liquid by mixing with chocolate milk, Ensure, or Advera within one hour of dosing.

To ensure continued stability of Norvir liquid, it should not be refrigerated and should be stored at room temperature (below 77°F/25°C) and used within 30 days of dispensing. It is important that the patient shakes the liquid well before each use.

Patients will receive Norvir liquid when their pharmacy runs out of Norvir capsules. After finishing their prescription for Norvir capsules, patients should begin taking Norvir liquid at their next scheduled dose. Conversion to Norvir liquid will depend on each individual pharmacy’s inventory of Norvir capsules. Please consider this information in making future prescribing decisions.

We are also communicating this information to pharmacists. In addition, enclosed is a letter that we are asking pharmacists to distribute to patients who receive Norvir liquid when their prescription is filled.

Norvir is indicated in adults in combination with other anti-retroviral agents or as monotherapy for the treatment of HIV infection. Norvir has also been cleared by the FDA for use in children between the ages of 2 and 16 based on safety and pharmacokinetic data.

Norvir is not a cure for HIV infection. People treated with Norvir may continue to acquire illnesses associated with advanced HIV infection, including opportunistic infections. Norvir may not be right for everyone, including people with liver disease, hepatitis, or hemophilia. Elevated blood sugar levels have been reported in patients taking protease inhibitors. Allergic reactions ranging from mild to severe have been reported. Common adverse reactions include fatigue, vomiting, diarrhea, loss of appetite, abdominal pain, taste disturbance, tingling sensation or numbness in the hands, feet, or around the lips, headache and dizziness. Norvir should not be used with certain medications including some non-sedating antihistamines, sedative hypnotics, antiarrhythmics, or ergot alkaloid preparations.

We deeply regret this inconvenience and appreciate your understanding and patience as we work to solve the problem. Abbott is committed to doing everything it can to allow patients to continue Norvir therapy without interruption, and to resuming timely delivery of Norvir capsules.

If you have questions or concerns, please call us at 1-800-637-2400 or visit our website at www.norvir.com. As always, your Abbott sales representative is available to assist you. Thank you for helping in our efforts to provide your patients with continued Norvir therapy.

Enclosed is Norvir full prescribing information.

Sincerely,

David Pizzuti, M.D.
Vice President, Medical Affairs
Pharmaceutical Products Division

Encl: Norvir Full Prescribing Information
Patient Letter
Dosing Guide

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