Metyrosine
Indications
Metyrosine is used for:
Chronic Pheochromocytoma
Adult Dose
Chronic Pheochromocytoma
Indicated for treatment of patients with pheochromocytoma for: 1) preoperative preparation for surgery; 2) management when surgery is contraindicated; and 3) chronic treatment with malignant pheochromocytoma
Initial: 250 mg PO q6hr; may increase by 250-500 mg/day, not to exceed 4 g/day
Maintenance: Typically 2-3 g/day divided q6hr
Child Dose
Renal Dose
Administration
Contra Indications
Hypersensitivity to metyrosine
Precautions
Additive sedative effects w/ alcohol and other CNS depressants
Take enough fluid to prevent crystalluria
Use caution in hepatic or renal impairment
Not recommended for essential HTN
Pregnancy-Lactation
Pregnancy Category: C
Lactation: not known if excreted into breast milk, use caution
Interactions
Adverse Effects
Side effects of Metyrosine :
>10%
Sedation (>20%)
1-10%
Diarrhea (10%)
Exrapyramidal Symptoms (10%)
Frequency Not Defined
Fatigue
Headache
Psychic Disturbances
Galactorrhea
Sexual dysfunction
Nausea
Vomiting
Xerostomia
Nasal stuffiness
Dysuria
Crystalluria
Mechanism of Action
Inhibits synthesis of endogenous catecholamines by inhibiting tyrosine hydroxylase