Pharmacology - Prothrombin Fluctuation Fluctuating

Pharmacology - Prothrombin Fluctuation

FLUCTUATING PROTHROMBIN TIME in COUMADIN Management

Patient Profile:

The patient is a 79-year-old female undergoing long-term noninvasive concurrent management of several cardiac and circulatory ailments related to Rheumatic Mitral

Valve Disease caused by Rheumatic Fever in childhood. She has a prior history of Arterial Thrombosis, Deep Venous Thrombosis (DVT), and early symptoms of Congestive Heart Failure (CHF), all of which subsided satisfactorily after implantation of porcine mitral valve at the age of 75.

She was able to resume her yearly visits to her European land of origin the first summer following her surgery without medical incident or discomfort. Blood clots recurred in her lower extremities, first observed in conjunction with recurring Venous

Thrombosis shortly after intercontinental air travel three years after her surgery, following two previous annual trips without medical incident. Her cardiologist prescribed Coumadin (warfarin) to manage her DVT symptoms and minimize the risk of cardiac clots, particularly in the upper chambers, despite her lowered risk for such clotting issues by virtue of her successful mitral valve surgery four years ago.

Presentation:

The patient first presented to the Emergency Room (ER) two days after returning to the United States from her most recent annual visit to her European homeland in June, complaining of acute DVT symptoms and shortness of breathe beginning the second morning at home and preventing her from getting out of bed. The patient's family advised that her present symptoms are reminiscent of her preoperative condition that precipitated her mitral valve replacement in 2003.

The patient has been successfully treated with 2.5 mg Coumadin per day ever since the previous summer, to relieve her first recurrence of DVT symptoms and CHF symptoms, both of which recurred for the first time since her surgery after her third trip abroad. Her cardiologist was consulted by telephone and advised against the most conservative treatment modalities, instructing the attending physician to contact him again before administering additional medications of any kind.

On her first presentation to the ER, she was treated with intravenous fluids and elevation of her affected extremities, which effectively resolved her symptoms without necessitating hospital admission. Shortly thereafter, her cardiologist determined through clinical evaluation and previously scheduled (twice-monthly) routine Prothrombin Time

PT) test, that her recurrent symptoms were related to prolonged acute exposure to high altitude air travel in a pressurized environment and decided against increasing her dosage of Coumadin or the administration of any other anticoagulant agents, at least until reviewing her next scheduled PT test results. Subsequent PT tests indicated no change in coagulation time and her medication schedule was not changed.

The following week, the same patient presented to the ER complaining of persistent nose bleeding on three successive nights in addition to bleeding in the mouth after flossing. The patient's family assures her physician that there have been no changes to her other medications and that the patient religiously follows dietetic advice to avoid certain green vegetables listed by her physician as contraindicated for patients taking

Coumadin. Nevertheless, an unscheduled PT test performed in the ER during her second visit provided markedly different results indicating a prolonged coagulation time despite no known changes to the patient's medication regimen or diet.

As a result of the results of the PT test performed in the ER, her physician lowered her daily dosage of Coumadin to 2 milligrams per day, with instructions to repeat PT testing weekly for the time being. Four days later, the patient returned to the ER complaining of excessive bleeding from the nose and gums (on flossing) again, despite following her physician's instructions to decrease her Coumadin dosage.

Administration of intravenous saline and elevation of the affected extremities again resolved her symptoms, but this time, she was admitted to the hospital for observation and more extensive testing scheduled by her cardiologist for the nest day.

Resolution:

While interviewing the patient and her family in great detail the next day, her physician inquired again into every over-the-counter (OTC) medication taken since her return from Europe and again reviewed dietary guidelines intended to avoid unintended interference with the desired effects her Coumadin regimen. The interview failed to disclose any medication interactions or dietary issues. Only after the interview concluded, did the patient ask "Doctor, does it matter what kind of tea I drink?" On the physician's subsequent inquiry, the patient disclosed that she had begun drinking Ginseng tea that a friend in Europe had suggested for "extra energy" and that she had tried the new tea two times: on the night before her first recurrence of DVT symptoms, as well as on the morning of the flight home. The physician advised that Ginseng has been shown, in at least one study, to decrease the effectiveness of Coumadin's anticoagulant effects.