The purpose of this study is to see if giving azidothymidine (AZT) to HIV-positive patients with hemophilia is safe and if it is effective in lowering HIV levels and boosting the immune system.

HIV infects and inactivates certain blood cells that are part of the body's immune system. The damage to the body's immune system can result in unusual infections and/or unusual forms of cancer. A large percentage of hemophiliacs are HIV-positive and there is a clear risk for the development of AIDS in these patients. AZT may be effective in lowering HIV levels and boosting the immune system but its side effects are not understood in these patients.

There is a clear risk for development of AIDS in hemophilic patients. AZT administration has been shown to inhibit HIV replication in vitro. Patients taking AZT have experienced fewer opportunistic infections and improvements in measures of immunity. The most common laboratory abnormalities observed with AZT are hematologic. However, the clinical and laboratory toxicity of AZT remains poorly understood in hemophiliacs. Hepatitis and liver dysfunction are more common in this population compared to other groups at risk for HIV infection. Because AZT is largely metabolized in the liver, drug pharmacokinetics needs to be evaluated in this patient population.

Both hemophiliacs and non-hemophiliacs take AZT for a period of 12 weeks. The first dose is administered intravenously. AZT is then given orally every 4 hours while awake (5 doses per day). Patients are evaluated by physical examinations and laboratory assessments. These include HIV culture of blood and leukocyte counts, lymphocyte counts, and lymphocyte subsets measured at study entry and every 4 weeks thereafter. Patients are hospitalized for pharmacokinetic studies at study entry and at Weeks 6 and 12. Each of these studies involves both intravenous and oral administration within 48 hours of one another. Blood is sampled at 0, 0.5, 1, 2, 3, 4, 6, 8, 10, and 12 hours after each administration and urine is collected every 2 hours for 12 hours.

Inclusion Criteria

You may be eligible for this study if you:

• Are HIV-positive.
• Have a bleeding disorder such as hemophilia A or B, a lack of factor VIII (a blood clotting factor), or severe von Willebrand's disease.
• Will be available for follow-up for at least a year.
• Are at least 12 years old (consent of parent or guardian required if under 18).
• Are willing to use an effective method of birth control during the study.

Exclusion Criteria

You will not be eligible for this study if you:

• Have a life-threatening opportunistic (AIDS-related) infection or AIDS-related symptoms.
• Have taken certain drugs within 30 days prior to study entry including chemotherapy and interferon.
• Are taking acetaminophen or drugs containing acetaminophen.
• Are pregnant or breast-feeding.