Study of Heparin Prophylaxis of Hereditary Angioedema Exacerbations

PROTOCOL ENTRY CRITERIA: --Disease Characteristics-- Confirmed diagnosis of hereditary angioedema (HAE) based upon C4 antigenic level, positive family history, and C1 inhibitor (C1INH) antigenic level (Type I HAE) or functional level (Type II HAE) Functional C1 within normal levels if diagnosis of acquired C1INH is possible Negative family history will not exclude as long as patient meets all other criteria, has normal C1 level, and has no evidence of acquired C1INH deficiency History of symptoms of HAE including episodic swelling, abdominal pain, and/or respiratory difficulty Experiencing a minimum of 1-2 HAE episodes within 6 weeks --Prior/Concurrent Therapy-- Endocrine therapy: Anabolic steroids allowed as long as dose has not been changed in at least 30 days Other: No concurrent and at least 1 week since prior aspirin, nonsteroidal antiinflammatory agents, dipyridamole, Coumadin-like drugs, or any other medication having an effect on coagulation or platelets --Patient Characteristics-- Hematopoietic: No clinically significant history of hematologic disease Hepatic: No clinically significant history of hepatic disease Renal: No clinically significant history of renal disease Cardiovascular: No clinically significant history of cardiac disease or hypertension Pulmonary: No clinically significant history of pulmonary disease Other: No contraindication to the use of inhaled or subcutaneous heparin No drug allergy that would interfere with the study No clinically significant history of: Malignancy Diabetes mellitus Neurologic disease Immunologic disease Bleeding disorder Infirmity No history of drug abuse, alcoholism, psychosis, or other psychological/psychiatric disorder