Figure 744

Tyrosine hydroxylase inhibitor. Metyrosine is the only drug in its class. The initial recommended dose is 1 g/d, given in divided doses. This may be increased by 250 to 500 mg daily to a maximum of 4 g/d. The usual effective dosage is 2 to 3 g/d. The maximum biochemical effect occurs within 2 to 3 days. In hypertensive patients in whom there is a response, blood pressure decreases progressively during the first days of therapy. In patients who are usually nor-motensive, the dose should be titrated to the amount that will reduce circulating or urinary catecholamines by 50% or more.

Following discontinuation of therapy, the clinical and biochemical effects may persist 2 to 4 days. Metyrosine is variably absorbed from the gastrointestinal tract; bioavailability ranges from 45% to 90%. Peak plasma concentrations are reached in 1 to 3 hours. The plasma half-life is 3 to 4 hours. Metyrosine is not metabolized; the unchanged drug is recovered in the urine. Drug dosage should be reduced in patients with renal insufficiency. Metyrosine is exclusively used in the management of preoperative or inoperative pheochromocytoma [6,9].

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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