phenoxybenzamine hydrochloride
Capsule · Oral
Uses
Phenoxybenzamine hydrochloride capsules are indicated in the treatment of pheochromocytoma, to control episodes of hypertension and sweating. If tachycardia is excessive, it may be necessary to use a beta -blocking agent concomitantly.
Dosage and administration
The dosage should be adjusted to fit the needs of each patient. Small initial doses should be slowly increased until the desired effect is obtained or the side effects from blockade become troublesome. After each increase, the patient should be observed on that level before instituting another increase . The dosage should be carried to a point where symptomatic relief and/or objective improvement are obtained, but not so high that the side effects from blockade become troublesome. Initially, 10 mg of phenoxybenzamine hydrochloride twice a day. Dosage should be increased every other day, usually to 20 to 40 mg 2 or 3 times a day, until an optimal dosage is obtained, as judged by blood pressure control. Long-term use of phenoxybenzamine is not recommended (see PRECAUTIONS Carcinogenesis and Mutagenesis ). STORAGE Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Dispense in a tight container.
Contraindications
Conditions where a fall in blood pressure may be undesirable; hypersensitivity to the drug or any of its components.
Warnings
Phenoxybenzamine hydrochloride-induced alpha -adrenergic blockade leaves beta -adrenergic receptors unopposed. Compounds that stimulate both types of receptors may, therefore, produce an exaggerated hypotensive response and tachycardia.
Precautions
General–Administer with caution in patients with marked cerebral or coronary arteriosclerosis or renal damage. Adrenergic blocking effect may aggravate symptoms of respiratory infections. Drug Interactions 2 – Phenoxybenzamine hydrochloride may interact with compounds that stimulate both alpha- and beta- adrenergic receptors (i.e., epinephrine) to produce an exaggerated hypotensive response and tachycardia. (See WARNING .) Phenoxybenzamine hydrochloride blocks hyperthermia production by levarterenol, and blocks hypothermia production by reserpine. Carcinogenesis and Mutagenesis Case reports of carcinoma in humans after long-term treatment with phenoxybenzamine have been reported. Hence long-term use of phenoxybenzamine is not recommended. 3, 4 Carefully weigh the benefits and risks before prescribing this drug. Phenoxybenzamine hydrochloride showed in vitro mutagenic activity in the Ames test and mouse lymphoma assay; it did not show mutagenic activity in vivo in the micronucleus test in mice. In rats and mice, repeated intraperitoneal administration of phenoxybenzamine hydrochloride (three times per week for up to 52 weeks) resulted in peritoneal sarcomas. Chronic oral dosing in rats (for up to 2 years) produced malignant tumors of the small intestine and non-glandular stomach, as well as ulcerative and/or erosive gastritis of the glandular stomach. Whereas squamous cell carcinomas of the non-glandular stomach were observed at all tested doses of phenoxybenzamine hydrochloride, there was a no-observed-effect-level of 10 mg/kg for tumors (carcinomas and sarcomas) of the small intestine. This dose is, on a body surface area basis, about twice the maximum recommended human dosage of 20 mg b.i.d. Pregnancy - Teratogenic Effects Adequate reproductive studies in animals have not been performed with phenoxybenzamine hydrochloride. It is also not known whether phenoxybenzamine hydrochloride can cause fetal harm when administered to a pregnant woman. Phenoxybenzamine hydrochloride should be given to a pregnant woman only if clearly needed. Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, and because of the potential for serious adverse reactions from phenoxybenzamine hydrochloride, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. Pediatric Use Safety and effectiveness in pediatric patients have not been established.
Side effects
The following adverse reactions have been observed, but there are insufficient data to support an estimate of their frequency. Autonomic Nervous System*: Postural hypotension, tachycardia, inhibition of ejaculation, nasal congestion, miosis. *These so-called “side effects” are actually evidence of adrenergic blockade and vary according to the degree of blockade. Miscellaneous: Gastrointestinal irritation, drowsiness, fatigue. To report SUSPECTED ADVERSE REACTIONS, contact Northstar Rx LLC at 1-800-206-7821 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Pregnancy
Pregnancy - Teratogenic Effects Adequate reproductive studies in animals have not been performed with phenoxybenzamine hydrochloride. It is also not known whether phenoxybenzamine hydrochloride can cause fetal harm when administered to a pregnant woman. Phenoxybenzamine hydrochloride should be given to a pregnant woman only if clearly needed.
Pediatric use
Pediatric Use Safety and effectiveness in pediatric patients have not been established.
Overdosage
These are largely the result of blocking of the sympathetic nervous system and of the circulating epinephrine. They may include postural hypotension, resulting in dizziness or fainting; tachycardia, particularly postural; vomiting; lethargy; shock.
Description
Each phenoxybenzamine hydrochloride capsule, USP with white opaque cap and body, is imprinted "PHEH" on cap and "10" on body, and contains 10 mg of phenoxybenzamine hydrochloride USP. Inactive ingredients consist of anhydrous lactose and talc. The capsule shell contains gelatin and titanium dioxide. The imprinting ink contains black iron oxide, potassium hydroxide, propylene glycol, and shellac. Phenoxybenzamine hydrochloride is N -(2-Chloroethyl)- N -(1-methyl-2-phenoxyethyl)benzylamine hydrochloride: Phenoxybenzamine hydrochloride USP is white or almost white crystalline powder with a molecular weight of 340.3, which melts between 136° and 141°C. It is freely soluble in ethanol, sparingly soluble in water. str
How supplied
PhenoxybenzamineHydrochloride Capsules USP, 10 mg are white opaque colored cap and white opaque colored body hard gelatin capsules, imprinted with “PHEH” on cap and “10” on body, filled with white to off-white powder. Bottle of 100 NDC 72603-229-01
Label text from the FDA structured product label by NorthStar Rx LLC (revised Jul 9, 2026). Long sections are shortened; the complete label is on DailyMed.
Active ingredients
- Phenoxybenzamine Hydrochloride in 6 products
phenoxybenzamine hydrochloride NDC products (6)
| NDC | Strength & form | Labeler | Type |
|---|---|---|---|
| 60219-1502 | Phenoxybenzamine Hydrochloride 10 mg/1 Capsule | Amneal Pharmaceuticals NY LLC | ANDA |
| 59651-327 | Phenoxybenzamine Hydrochloride 10 mg/1 Capsule | Aurobindo Pharma Limited | ANDA |
| 35573-473 | Phenoxybenzamine Hydrochloride 10 mg/1 Capsule | Burel Pharmaceuticals, LLC | ANDA |
| 72603-229 | Phenoxybenzamine Hydrochloride 10 mg/1 Capsule | NorthStar Rx LLC | ANDA |
| 70954-365 | Phenoxybenzamine Hydrochloride 10 mg/1 Capsule | Novitium Pharma LLC | ANDA |
| 16571-874 | Phenoxybenzamine Hydrochloride 10 mg/1 Capsule | Rising Pharma Holdings, Inc. | ANDA |
Frequently asked questions
What is phenoxybenzamine hydrochloride used for?
Phenoxybenzamine hydrochloride capsules are indicated in the treatment of pheochromocytoma, to control episodes of hypertension and sweating. If tachycardia is excessive, it may be necessary to use a beta -blocking agent concomitantly.
What are the side effects of phenoxybenzamine hydrochloride?
The following adverse reactions have been observed, but there are insufficient data to support an estimate of their frequency. Autonomic Nervous System*: Postural hypotension, tachycardia, inhibition of ejaculation, nasal congestion, miosis. *These so-called “side effects” are actually evidence of adrenergic blockade and vary according to the degree of blockade. Miscellaneous: Gastrointestinal… See the full label for the complete list.
Who makes phenoxybenzamine hydrochloride?
phenoxybenzamine hydrochloride is listed by 6 labelers in the FDA NDC directory, including Amneal Pharmaceuticals NY LLC, Aurobindo Pharma Limited, Burel Pharmaceuticals, LLC, NorthStar Rx LLC.