alpha-Methyl-p-tyrosine: a review of its pharmacology and clinical use.

alpha-Methyl-p-tyrosine is an orally active inhibitor of catecholamine synthesis which inhibits the hydroxylation of tyrosine to dopa. At dosages of 600 to 3500 mg daily it is effective in controlling the hypertensive episodes and symptoms of catecholamine excess in phaeochromocytoma during preparation for surgery. Limited published experience suggests that it is effective in controlling hypertension and symptoms in malignant phaeochromocytoma, but further long term experience is needed. Concomitant administration of phenoxybenzamine and propranolol may be desirable in some patients and treatment with phentolamine is usually necessary to control hypertension during manipulation of the tumour.