Propranolol to Treat Fainting in Children With Sympathoadrenal Imbalance

INCLUSION CRITERIA: Subjects are patients referred for evaluation of chronic orthostatic intolerance. Patients enter into the therapeutic trial after they are determined to have NCS with SAI in a screening evaluation. Participation in this protocol is offered to individuals 10-17 years of age, independently of gender, race, ethnicity, religion, or any other demographic or sociopolitical classifications. To be eligible to enter this study, the patient must have a minimum frequency of pre-syncope of at least 1 event/2 months, or syncope of at least once/4 months. The severity of the symptoms should be of such severity as to alter the individual's quality of life or routines of life. EXCLUSION CRITERIA: Age: Minors younger than 10 years old and pregnant female subjects between 10 and 17 years of age will be excluded. Risk: A candidate subject is excluded if, in the judgment of the Principal Investigator, protocol participation would place the subject at substantially increased acute medical risk. This includes the risk associated with air travel to the NIH. A candidate subject is excluded if, in the opinion of the Principal Investigator, the medical risk outweighs the potential scientific benefit. Disqualifying Conditions: A candidate subject is excluded if there is a disqualifying condition. Examples of disqualifying conditions are history of asthma or chronic obstructive pulmonary disease requiring bronchodilators, hepatic or renal failure, atrioventricular block of any degree, bradycardia, symptomatic congestive heart failure, severe anemia, psychosis, refractory ventricular arrhythmias, insulin-dependent diabetes mellitus, or psychiatric disorders requiring continuous drug treatment. Patients with known allergy or hypersensitivity to propranolol are excluded from this study. A positive HIV test result does not necessarily exclude a patient from participating. If a female subject becomes pregnant during the study, she will be excluded from further participation in the study. Medications: A candidate subject is excluded if clinical considerations require that the patient continue treatment with a drug likely to interfere with the scientific results. Patients who must take medications daily in the following categories are excluded: anticoagulants, tricyclic antidepressants, barbiturates, aspirin, acetaminophen, insulin, and bronchodilators. Patients are not to discontinue any medications before the patient or the patient's doctor discusses this with the Principal Investigator, an Associated Investigator, or Research Nurse. If it is decided that discontinuing medications would be unsafe, then the patient is excluded from the study. Herbal Medicines and Dietary Supplements: Certain herbal medicines or dietary supplements are known or suspected to interfere with the experimental results, and such herbal medicines or dietary supplements must be discontinued before enrollment in the study. For many herbal medicines or dietary supplements, the mechanisms of action and therefore the possible effects on the experimental results are unknown. In cases where the subjects wish to continue their herbal medicines or dietary supplements while in study, and search the available medical literature fails to identify effects that are known or expected to interfere with the experimental results, then the subjects may participate. Practical Limitations: Patients in whom we feel it would be difficult to technically carry out the testing procedures are excluded. Pregnancy: Pregnant or lactating females of child-bearing potential are excluded. A blood test pregnancy will be conducted in all females of childbearing potential, before intake evaluation and also before each drug treatment phase. During the course of the protocol, patients who are of childbearing potential will be advised to practice adequate contraception (birth control pills, Depo-Provera, or implanted intrauterine device), if sexually active. If during the course of this study, a minor patient is found to have a positive pregnancy test, she will be asked confidentially whether she has had any recent sexual activity that could have resulted in the test being positive. In agreement with current legal statutes, the minor patient will be told confidentially that she is pregnant. She will be encouraged to share this information with her parents. By current legal statutes, we will not directly divulge this information to her parents. The pregnant minor subject will also be told that further participation in the study is a protocol violation (because of possible adverse risks to the unborn fetus), and she will be terminated from continued participation in the protocol.