Metyrosine

Drug overview for METYROSINE (metyrosine):

Generic name: METYROSINE (me-TYE-roe-seen)
Drug class: Pheochromocytoma treatment agents
Therapeutic class: Cardiovascular Therapy Agents

Metyrosine is an inhibitor of catecholamine synthesis.

No enhanced Uses information available for this drug.

DRUG IMAGES

No Image Available

The following indications for METYROSINE (metyrosine) have been approved by the FDA:

Indications:
Pheochromocytoma adjunct therapy

Professional Synonyms:
Adjunct medication therapy for pheochromocytoma

Dosing information for METYROSINE
DRUG LABEL	DOSING TYPE	DOSING INSTRUCTIONS
METYROSINE 250 MG CAPSULE	Maintenance	Adults take 1 capsule (250 mg) by oral route 4 times per day

Generic dosing information for METYROSINE
DRUG LABEL	DOSING TYPE	DOSING INSTRUCTIONS
METYROSINE 250 MG CAPSULE	Maintenance	Adults take 1 capsule (250 mg) by oral route 4 times per day

The following drug interaction information is available for METYROSINE (metyrosine):

Contraindicated
Severe
Moderate

There are 0 contraindications.

There are 0 severe interactions.

There are 2 moderate interactions. The clinician should assess the patient’s characteristics and take action as needed. Actions required for moderate interactions include, but are not limited to, discontinuing one or both agents, adjusting dosage, altering administration.

Drug Interaction	Drug Names
Tizanidine/Selected Antihypertensives SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Tizanidine is an alpha-2 agonist. Concurrent use with antihypertensive agents may result in additive effects on blood pressure.(1) CLINICAL EFFECTS: Concurrent use of antihypertensives and tizanidine may result in hypotension.(1) PREDISPOSING FACTORS: None determined. PATIENT MANAGEMENT: Patients receiving concurrent therapy should be monitored for hypotension. The risk of hypotension may be decreased by careful titration of tizanidine dosages and monitoring for hypotension prior to dose advancement. Counsel patients about the risk of orthostatic hypotension.(1) DISCUSSION: Severe hypotension has been reported following the addition of tizanidine to existing lisinopril therapy.(2-4)	TIZANIDINE HCL, ZANAFLEX
Apomorphine/Selected Antihypertensives and Vasodilators SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed. MECHANISM OF ACTION: Apomorphine causes dose-dependent decreases in blood pressure. Concurrent use with antihypertensive agents may result in additive effects on blood pressure.(1) CLINICAL EFFECTS: Concurrent use of antihypertensives and apomorphine may result in orthostatic hypotension with or without dizziness, nausea, or syncope.(1) PREDISPOSING FACTORS: The risk of orthostatic hypotension may be increased during dose escalation of apomorphine and in patients with renal or hepatic impairment.(1) PATIENT MANAGEMENT: Patients receiving concurrent therapy should be monitored for hypotension. Counsel patients about the risk of orthostatic hypotension.(1) DISCUSSION: Healthy volunteers who took sublingual nitroglycerin (0.4 mg) concomitantly with apomorphine experienced a mean largest decrease in supine systolic blood pressure (SBP) of 9.7 mm Hg and in supine diastolic blood pressure (DBP) of 9.3 mm Hg, and a mean largest decrease in standing SBP and DBP of 14.3 mm Hg and 13.5 mm Hg, respectively. The maximum decrease in SBP and DBP was 65 mm Hg and 43 mm Hg, respectively. When apomorphine was taken alone, the mean largest decrease in supine SBP and DBP was 6.1 mm Hg and 7.3 mm Hg, respectively, and in standing SBP and DBP was 6.7 mm Hg and 8.4 mm Hg, respectively.(1)	APOKYN, APOMORPHINE HCL, ONAPGO

Drug Interaction

Drug Names

Tizanidine/Selected Antihypertensives

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Tizanidine is an alpha-2 agonist. Concurrent use with antihypertensive agents may result in additive effects on blood pressure.(1)

CLINICAL EFFECTS: Concurrent use of antihypertensives and tizanidine may result in hypotension.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Patients receiving concurrent therapy should be monitored for hypotension. The risk of hypotension may be decreased by careful titration of tizanidine dosages and monitoring for hypotension prior to dose advancement. Counsel patients about the risk of orthostatic hypotension.(1)

DISCUSSION: Severe hypotension has been reported following the addition of tizanidine to existing lisinopril therapy.(2-4)

TIZANIDINE HCL, ZANAFLEX

Apomorphine/Selected Antihypertensives and Vasodilators

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Apomorphine causes dose-dependent decreases in blood pressure. Concurrent use with antihypertensive agents may result in additive effects on blood pressure.(1)

CLINICAL EFFECTS: Concurrent use of antihypertensives and apomorphine may result in orthostatic hypotension with or without dizziness, nausea, or syncope.(1)

PREDISPOSING FACTORS: The risk of orthostatic hypotension may be increased during dose escalation of apomorphine and in patients with renal or hepatic impairment.(1)

PATIENT MANAGEMENT: Patients receiving concurrent therapy should be monitored for hypotension. Counsel patients about the risk of orthostatic hypotension.(1)

DISCUSSION: Healthy volunteers who took sublingual nitroglycerin (0.4 mg) concomitantly with apomorphine experienced a mean largest decrease in supine systolic blood pressure (SBP) of 9.7 mm Hg and in supine diastolic blood pressure (DBP) of 9.3 mm Hg, and a mean largest decrease in standing SBP and DBP of 14.3

mm Hg and 13.5 mm Hg, respectively. The maximum decrease in SBP and DBP was 65 mm Hg and 43 mm Hg, respectively.

When apomorphine was taken alone, the mean largest decrease in supine SBP and DBP was 6.1 mm Hg and 7.3 mm Hg, respectively, and in standing SBP and DBP was 6.7

mm Hg and 8.4 mm Hg, respectively.(1)

APOKYN, APOMORPHINE HCL, ONAPGO

The following contraindication information is available for METYROSINE (metyrosine):

Overview
Contraindicated
Severe
Moderate

Drug contraindication overview.

No enhanced Contraindications information available for this drug.

There are 0 contraindications.

There are 4 severe contraindications. Adequate patient monitoring is recommended for safer drug use.

Severe List
Crystalluria
Extrapyramidal disease
Hypotension
Hypovolemia

There are 4 moderate contraindications. Clinically significant contraindication, where the condition can be managed or treated before the drug may be given safely.

Moderate List
Depression
Disease of liver
Kidney disease with reduction in glomerular filtration rate (GFr)
Urolithiasis

The following adverse reaction information is available for METYROSINE (metyrosine):

Overview
Severe
Less Severe

Adverse reaction overview.

No enhanced Common Adverse Effects information available for this drug.

There are 19 severe adverse reactions.

More Frequent	Less Frequent
Extrapyramidal disease Severe diarrhea	None.

Rare/Very Rare
Allergic dermatitis Anaphylaxis Anemia Angioedema Crystalluria Dyspnea Dysuria Eosinophilia Hallucinations Hematuria Parkinsonism Pharyngeal edema Thrombocytopenic disorder Thrombocytosis Trismus Urolithiasis Urticaria

There are 17 less severe adverse reactions.

More Frequent	Less Frequent
Drowsy Sedation	Acute abdominal pain Disorder of ejaculation Erectile dysfunction Galactorrhea not associated with childbirth Gynecomastia Headache disorder Nasal congestion Nausea Vomiting Xerostomia

Rare/Very Rare
Acute cognitive impairment Depression Peripheral edema Skin rash Symptoms of anxiety

The following precautions are available for METYROSINE (metyrosine):

Pediatric
Pregnant
Lactation
Geriatric

No enhanced Pediatric Use information available for this drug.

Contraindicated

None

Severe Precaution

None

Management or Monitoring Precaution

None

Animal reproduction studies using metyrosine have not been performed to date. It is not known whether metyrosine can cause fetal harm when administered to pregnant women. There are no adequate and controlled studies to date using metyrosine in pregnant women. Metyrosine should be used during pregnancy only when clearly needed.

Since it is not known whether metyrosine is distributed into milk, the drug should be used with caution in nursing women.

No enhanced Geriatric Use information available for this drug.

Pheochromocytoma adjunct therapy
C74.1	Malignant neoplasm of medulla of adrenal gland
C74.10	Malignant neoplasm of medulla of unspecified adrenal gland
C74.11	Malignant neoplasm of medulla of right adrenal gland
C74.12	Malignant neoplasm of medulla of left adrenal gland
D35.0	Benign neoplasm of adrenal gland
D35.00	Benign neoplasm of unspecified adrenal gland
D35.01	Benign neoplasm of right adrenal gland
D35.02	Benign neoplasm of left adrenal gland
E31.22	Multiple endocrine neoplasia [MEn] type IIA
E31.23	Multiple endocrine neoplasia [MEn] type IIB