Phenoxybenzamine Hydrochloride

Description

DESCRIPTION Each Phenoxybenzamine Hydrochloride Capsule, USP 10 mg is a size #3 capsule with red transparent cap and body, imprinted “365” on cap and “novitium 10 mg” on body with grey ink, filled with white to off white powder containing 10 mg of Phenoxybenzamine Hydrochloride USP and the following inactive ingredients: lactose and talc. Each of the empty hard gelatin capsule contains gelatin, purified water, sodium lauryl sulfate, D&C Red 33, FD&C Yellow 6 and FD&C Red 3. The imprinting ink contains the following: shellac, dehydrated alcohol, isopropyl alcohol, butyl alcohol, propylene glycol, strong ammonia solution, potassium hydroxide, titanium dioxide, black iron oxide and purified water. Phenoxybenzamine Hydrochloride is N-(2-Chloroethyl)-N-(1-methyl-2-phenoxyethyl) benzylamine hydrochloride: Phenoxybenzamine hydrochloride is a white to off-white powder with a molecular weight of 340.3, which melts between 136° and 141°C. It is soluble in water, alcohol and chloroform; insoluble in ether. structure

What Is Phenoxybenzamine Hydrochloride Used For?

INDICATIONS & USAGE 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

DOSAGE & 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).

Side Effects (Adverse Reactions)

ADVERSE REACTIONS 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 Novitium Pharma, LLC at 1-855-204-1431 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Drug Interactions

DRUG INTERACTIONS 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 WARNINGS.) Phenoxybenzamine hydrochloride blocks hyperthermia production by levarterenol, and blocks hypothermia production by reserpine.

Contraindications

CONTRAINDICATIONS Conditions where a fall in blood pressure may be undesirable; hypersensitivity to the drug or any of its components.

Pregnancy and Breastfeeding

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.

Overdosage

OVERDOSAGE SYMPTOMS − 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. TREATMENT When symptoms and signs of overdosage exist, discontinue the drug. Treatment of circulatory failure, if present, is a prime consideration. In cases of mild overdosage, recumbent position with legs elevated usually restores cerebral circulation. In the more severe cases, the usual measures to combat shock should be instituted. Usual pressor agents are not effective. Epinephrine is contraindicated because it stimulates both alpha - and beta -receptors; since alpha -receptors are blocked, the net effect of epinephrine administration is vasodilation and a further drop in blood pressure (epinephrine reversal). The patient may have to be kept flat for 24 hours or more in the case of overdose, as the effect of the drug is prolonged. Leg bandages and an abdominal binder may shorten the period of disability. I.V. Infusion of levarterenol bitartrate** may be used to combat severe hypotensive reactions, because it stimulates alpha -receptors primarily. Although phenoxybenzamine hydrochloride is an alpha -adrenergic blocking agent, a sufficient dose of levarterenol bitartrate will overcome this effect. The oral LD 50 for phenoxybenzamine hydrochloride is approximately 2000 mg/kg in rats and approximately 500 mg/kg in guinea pigs.

How Supplied

HOW SUPPLIED Phenoxybenzamine Hydrochloride Capsules, USP 10 mg are supplied as size #3 capsule with red transparent cap and body, imprinted “365” on cap and “novitium 10 mg” on body with grey ink, filled with white to off white powder in bottles of 100 (NDC 70954-365-10).