Skip to Content

Mecamylamine

Generic Name: mecamylamine (meck a MILL a meen)
Brand Name: Inversine, Vecamyl

Medically reviewed on December 15, 2017

What is mecamylamine?

Mecamylamine is used to treat moderate to severe hypertension (high blood pressure). Because of its many side effects, mecamylamine is not commonly used.

Mecamylamine may also be used for purposes other than those listed in this medication guide.

Important Information

Use caution when driving, operating machinery, or performing other hazardous activities. Mecamylamine may cause dizziness. If you experience dizziness, avoid these activities.

If you experience dizziness, rise slowly from a sitting or lying position to avoid falling.

Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking mecamylamine.

Take mecamylamine every day at the same time, usually after meals.

Call your doctor if you experience tremor, abdominal pain, abdominal distention, or diarrhea.

Who should not take mecamylamine?

Before taking this medication, tell your doctor if you

You may not be able to take mecamylamine, or you may require a lower dose or special monitoring during treatment if you have any of the conditions listed above.

Mecamylamine is in the FDA pregnancy category C. This means that it is not known whether mecamylamine will harm an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant.

It is not known whether mecamylamine passes into breast milk. Do not take mecamylamine without first talking to your doctor if you are breast-feeding a baby.

How should I take mecamylamine?

Take mecamylamine exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose with a full glass of water.

Take mecamylamine after meals.

Take each dose at the same time every day.

Do not stop taking this medication unless your doctor approves. Not taking your medication could make your condition much worse.

Store mecamylamine at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take only your next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

Seek emergency medical attention.

Symptoms of a mecamylamine overdose include fainting, dizziness, weakness, confusion, nausea, vomiting, diarrhea, constipation, difficulty urinating, anxiety, dry mouth, large pupils, blurred vision, and an irregular heartbeat.

What should I avoid while taking this mecamylamine?

Use caution when driving, operating machinery, or performing other hazardous activities. Mecamylamine may cause dizziness. If you experience dizziness, avoid these activities.

If you experience dizziness, rise slowly from a sitting or lying position to avoid falling.

Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking mecamylamine.

Mecamylamine side effects

If you experience any of the following serious side effects, stop taking mecamylamine and seek emergency medical attention:

  • an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives); or

  • abdominal pain, abdominal distention, or diarrhea.

Other, less serious side effects may be more likely to occur. Continue to take mecamylamine and talk to your doctor if you experience

  • nausea, vomiting, or constipation;

  • dry mouth;

  • decreased appetite;

  • dizziness and fainting;

  • drowsiness or weakness;

  • dilated (large) pupils and blurred vision; or

  • difficulty urinating.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

Mecamylamine dosing information

Usual Adult Dose for Hypertension:

2.5 mg orally twice a day; may increase by one 2.5 mg tablet at intervals of 2 days or more until desired blood pressure response is achieved.

Comments:
-The average total daily dose is 25 mg, usually in 3 divided doses; however, 2.5 mg daily may be sufficient. Partial tolerance may develop in certain patients, which requires an increase in the total daily dose.
-Four or more doses may be required when smooth control is difficult to obtain.
-Titration should be determined by blood pressure readings in the erect position at the time of maximal effect of this drug, as well as by signs and symptoms of orthostatic hypotension. In severe or urgent cases, titration at larger increments and shorter intervals may be needed.

Use: Management of moderately severe to severe essential hypertension and uncomplicated cases of malignant hypertension.

What other drugs will affect mecamylamine?

Generally, mecamylamine should not be used during treatment with antibiotics or sulfa-based drugs. Tell your doctor if you are taking drugs of either of these types.

Other drugs used to lower high blood pressure may increase the effects of mecamylamine, and serious side effects could occur. Tell your doctor about all medicines you take to lower high blood pressure or to treat other heart conditions.

Anesthesia (use of drugs that put you to sleep for surgery) may also increase the effects of mecamylamine. Tell your doctor or dentist that you are taking mecamylamine before you have surgery.

Drugs other than those listed here may also interact with mecamylamine or affect your condition. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

Further information

  • Your pharmacist has additional information about mecamylamine written for health professionals that you may read.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Hide