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Drugs A–Z

Mecamylamine Hydrochloride

Mecamylamine Hydrochloride is a prescription medicine. The sections below reproduce one FDA label for it, named under "Label". Products in other forms, strengths or from other makers have their own labels, which can differ.

Type
Prescription only (Rx)
Brand names
Vecamyl
Taken
Oral
Label
TILDE Sciences LLC, revised February 20, 2025 · full label on DailyMed
Generic
FDA-approved (1 company) · details

What it is used for

For the management of moderately severe to severe essential hypertension and in uncomplicated cases of malignant hypertension.

Who should not take it (contraindications)

Mecamylamine HCl should not be used in mild, moderate, labile hypertension and may prove unsuitable in uncooperative patients. It is contraindicated in coronary insufficiency or recent myocardial infarction. Mecamylamine HCl should be given with great discretion, if at all, when renal insufficiency is manifested by a rising or elevated BUN. The drug is contraindicated in uremia. Patients receiving antibiotics and sulfonamides should generally not be treated with ganglion blockers. Other contraindications are glaucoma, organic pyloric stenosis or hypersensitivity to the product.

Warnings

Mecamylamine, a secondary amine, readily penetrates into the brain and thus may produce central nervous system effects. Tremor, choreiform movements, mental aberrations, and convulsions may occur rarely. These have occurred most often when large doses of Mecamylamine HCl were used, especially in patients with cerebral or renal insufficiency. When ganglion blockers or other potent antihypertensive drugs are discontinued suddenly, hypertensive levels return. In patients with malignant hypertension and others, this may occur abruptly and may cause fatal cerebral vascular accidents or acute congestive heart failure. When Mecamylamine HCl is withdrawn, this should be done gradually and other antihypertensive therapy usually must be substituted. On the other hand, the effects of Mecamylamine HCl sometimes may last from hours to days after therapy is discontinued.

Precautions

General The patient's condition should be evaluated carefully, particularly as to renal and cardiovascular function. When renal, cerebral, or coronary blood flow is deficient, any additional impairment, which might result from added hypotension, must be avoided. The use of Mecamylamine HCl in patients with marked cerebral and coronary arteriosclerosis or after a recent cerebral accident requires caution. The action of Mecamylamine HCl may be potentiated by excessive heat, fever, infection, hemorrhage, pregnancy, anesthesia, surgery, vigorous exercise, other antihypertensive drugs, alcohol, and salt depletion as a result of diminished intake or increased excretion due to diarrhea, vomiting, excessive sweating, or diuretics. During therapy with Mecamylamine HCl, sodium intake should not be restricted but, if necessary, the dosage of the ganglion blocker must be adjusted. Since urinary retention may occur in patients on ganglion blockers, caution is required in patients with prostatic hypertrophy, bladder neck obstruction, and urethral stricture. Frequent loose bowel movements with abdominal distention and decreased borborygmi may be the first signs of paralytic ileus. If these are present, Mecamylamine HCl should be discontinued immediately and remedial steps taken. Information for Patients Mecamylamine HCl may cause dizziness, lightheadedness, or fainting, especially when rising from a lying or sitting position. This effect may be increased by alcoholic beverages, exercise, or during hot weather. Getting up slowly may help alleviate such a reaction. Drug Interactions Patients receiving antibiotics and sulfonamides generally should not be treated with ganglion blockers. The action of Mecamylamine HCl may be potentiated by anesthesia, other antihypertensive drugs and alcohol. Carcinogenesis, Mutagenesis, Impairment of Fertility Long-term studies in animals have not been performed to evaluate the effects upon fertility, mutagenic or carcinogenic potential of Mecamylamine HCl. Pregnancy Pregnancy Category C. Animal reproduction studies have not been conducted with Mecamylamine HCl. It is not known whether Mecamylamine HCl can cause fetal harm when given to a pregnant woman or can affect reproductive capacity. Mecamylamine HCl should be given to a pregnant woman only if clearly needed. Nursing Mothers Because of the potential for serious adverse reactions in nursing infants from Mecamylamine HCl, 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 (adverse reactions)

The following adverse reactions have been reported and within each category are listed in order of decreasing severity. Gastrointestinal: Ileus, constipation (sometimes preceded by small, frequent liquid stools), vomiting, nausea, anorexia, glossitis and dryness of mouth. Cardiovascular: Orthostatic dizziness and syncope, postural hypotension. Nervous System/Psychiatric: Convulsions, choreiform movements, mental aberrations, tremor, and paresthesias (see WARNINGS ). Respiratory: Interstitial pulmonary edema and fibrosis. Urogenital: Urinary retention, impotence, decreased libido. Special Senses: Blurred vision, dilated pupils. Miscellaneous: Weakness, fatigue, sedation.

Drug interactions

Patients receiving antibiotics and sulfonamides generally should not be treated with ganglion blockers. The action of Mecamylamine HCl may be potentiated by anesthesia, other antihypertensive drugs and alcohol.

Pregnancy

Pregnancy Category C. Animal reproduction studies have not been conducted with Mecamylamine HCl. It is not known whether Mecamylamine HCl can cause fetal harm when given to a pregnant woman or can affect reproductive capacity. Mecamylamine HCl should be given to a pregnant woman only if clearly needed.

Breastfeeding

Because of the potential for serious adverse reactions in nursing infants from Mecamylamine HCl, 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.

Use in children

Safety and effectiveness in pediatric patients have not been established.

Is there a generic Mecamylamine Hydrochloride?

Yes. The FDA has approved generic Mecamylamine Hydrochloride from 1 company, and the approval is active. The earliest of these was approved in 2013.

An FDA approval does not always mean the generic is already in pharmacies: patent disputes and settlements can delay a launch for years. Your pharmacist can tell you whether a generic is actually available and covered by your plan.

Companies with an approved generic

Lgm Pharma

Brand-name versions

  • Inversine Targacept, approved 1956 Discontinued

Source: Drugs@FDA (via openFDA), checked October 29, 2026. Marketing status is what companies report to the FDA; whether a pharmacy stocks a product, and what your insurance covers, can differ.

Dosage:
we do not reproduce dosing instructions. The right dose depends on the person and the condition and is set by the prescriber or pharmacist. Dosage section of the full label.

Mecamylamine in the news

We have not covered this medicine yet. Latest news

Recalls

No recalls matched to this medicine in FDA enforcement reports from the last 3 years (or older ones still open). Search all recalls

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Source: FDA structured product labeling, retrieved through openFDA. Label text is shown as published by the FDA, without editing; long sections are shortened, marked […]. openFDA data are not validated for clinical use — always check the current label and ask a doctor or pharmacist about your own treatment. Set ID 0b149023-f7a8-442d-ac69-295df8e66ed3.


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Important: this content is for informational purposes only and is not medical advice, a prescribing instruction, or a recommendation to act. Consult a licensed healthcare professional before taking any medication.

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