PPH Resulting From Fen Phen

Diagnosing Primary Pulmonary Hypertension As A Result Of Exposure To Diet Drugs

Diet drug induced pulmonary hypertension exists where medical evidence
indicates that anorexic medications were substantial factors causing individuals to suffer from potentially fatal instances of elevated pulmonary and right_sided heart pressures, a/k/a Primary Pulmonary Hypertension ("PPH"). Diet drug induced pulmonary hypertension is normally established through investigation of other potential causes for elevated pulmonary and right_sided heart pressures. Other potential causes for these elevated pressures may include severe sleep apnea, emphysema, pulmonary emboli, some congenital heart defects, left heart failure, autoimmune disorders and other conditions.

A basic means of investigating the existence of diet drug induced PPH is by conducting echocardiographic testing. Echocardiography is a non_invasive ultrasound examination of a patient's heart. Echocardiography testing indicates the presence of PPH by providing an estimation of the systolic pulmonary artery pressure. Some echocardiographic signs of moderate to severe pulmonary hypertension include significant tricuspid regurgitaion, dilated pulmonary arteries, right atrial and right ventricular dilation and movement of the interventricular septum.

A more precise measurement of pulmonary pressures requires a cardiac catheterization. A cardiac catheterization is an invasive procedure and the test itself can be risky. Cardiac catheterization can be a more definitive means of diagnosing PPH. Pulmonary hypertension is suspected if there is a pulmonary artery mean pressure which is 25 at rest or 30 with exercise. The only way to measure this pulmonary artery mean pressure is through cardiac catheterization. In addition, catheterization can reliably measure left heart pressures and can eliminate left heart failure as a cause of pulmonary hypertension.

An optional exercise right_heart catheterization is available in advanced catheterization clinics. Some diet drug victims have suggested that combining a cardiac catheterization with an exercise component may be another way to unmask pulmonary hypertension, particularly for those experiencing severe breathing problems subsequent to diet drug exposure but whose resting pulmonary artery pressures are otherwise believed to be normal.

During an exercise right_heart catheterization, various pressures are measured at rest and then again while the patient exercises. In diet drug patients, upper body exercise may elicit increased pulmonary artery pressures. During exercise, pulmonary function tests are performed. The machine can tell when the anaerobic threshold is reached. The anaerobic threshold is reached much sooner in those with pulmonary hypertension because of the inability of the pulmonary arteries to function normally. Physicians often test the patient's pulmonary artery pressure response to vasodilators during the heart catheterization procedure. It is believed that only approximately twenty_five percent (25%) of all pulmonary hypertension patients are responders to vasodilators, meaning that their pulmonary artery pressures fall in response to a vasodilator challenge. Approximately, seventy_five percent (75%) are believed to be non_responders and can actually get worse if given vasodilators. Knowing the vasodilator status of a patient is essential in determining future medical management. Some physicians will order a second catheterization for a patient if the vasodilator status was not determined by a initial cardiac catheterization.

Vasodilator protocols are only performed in certain medical centers throughout the country. These include (1) Columbia University in New York, New York; (2) University of Maryland in Baltimore, Maryland; (3) The University of Alabama in Birmingham, Alabama; (4) Harbor_UCLA Medical Center in Torrance, California; (5) Cedars Sinai Medical Center in Los Angeles, California; (6) University of North Carolina, Chapel Hill, North Carolina; (7) Mayo Clinic Medical Center in Rochester, Minnesota; (8) The University of Illinois in Chicago, Illinois; (9) The University of Colorado Health Sciences Center in Denver, Colorado; (10) The Duke Medical Center in Durham, North Carolina; (11) Baylor College of Medicine in Houston, Texas; (12) The Presbyterian_University Hospital in Pittsburgh, Pennsylvania; and (13) McGill University in Montreal, Canada.

In addition, other testing may be done to help diagnose PPH or rule out other causes for diet drug induced pulmonary hypertension. These tests include EKGs, X_rays, standard pulmonary functions tests, ventilation perfusion lung scans, sleep apnea studies and blood tests. Early detection and treatment is essential. Early medical management can improve long_term survival and quality of life in what is often an otherwise relentlessly progressive and fatal disease.

Background

The drugs Fenfluramine (PONDIMIN), Dexfenfluramine (REDUX) and Phentermine were approved by the Food and Drug Administration to be used separately. However, the "off_label" use of these drugs in combination never received FDA approval and was never properly tested through clinical trials.