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Generic name: mecamylamine (meck a MILL a meen)
Brand name: Vecamyl
Drug class: Antiadrenergic agents, peripherally acting

Medically reviewed by on Dec 4, 2019. Written by Cerner Multum.

What is Vecamyl?

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

Vecamyl is also used to treat malignant hypertension (extremely high blood pressure that comes on suddenly). Malignant hypertension can damage organs in the body if left untreated.

Vecamyl may also be used for purposes not listed in this medication guide.


Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

You should not use Vecamyl if you are allergic to it, or if you have:

  • mild, moderate, or well-controlled hypertension;

  • severe kidney disease, or kidney failure;

  • glaucoma;

  • a blockage in your stomach or intestines;

  • poor blood flow to your heart; or

  • if you have recently had a heart attack.

Some drugs should not be used together with Vecamyl. Your doctor may change your treatment plan if you also use an antibiotic or sulfa drug.

Tell your doctor if you have ever had:

  • a heart attack or stroke;

  • coronary artery disease (clogged or hardened arteries);

  • kidney disease;

  • urination problems;

  • a chronic infection;

  • bleeding problems; or

  • if you are on a low-salt diet.

It is not known whether Vecamyl will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

You should not breastfeed while using Vecamyl.

How should I take Vecamyl?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Take Vecamyl after meals.

Allow for the same time interval between your meals and your Vecamyl doses. For example, if you take your medicine 15 minutes after eating, take it that way each time.

You may need different amounts of this medicine at different times of the day. Follow your doctor's dosing instructions very carefully. Do not change your dose or stop taking the medicine without your doctor's advice.

Your blood pressure will need to be checked often and you may need other medical tests.

Call your doctor at once if you have a fever, if you are sick with vomiting or diarrhea, or if you are sweating more than usual.

If you need surgery, tell your surgeon you currently use this medicine.

You should not stop using Vecamyl suddenly. Stopping suddenly may make your condition worse.

Store at room temperature away from moisture and heat.

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What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include dizziness, weakness, vision problems, fainting, dry mouth, nausea, vomiting, diarrhea, constipation, urination problems, anxiety, or pounding heartbeats.

What should I avoid while taking this Vecamyl?

Avoid becoming overheated or dehydrated during exercise and in hot weather.

Avoid driving or hazardous activity until you know how Vecamyl will affect you. Your reactions could be impaired.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Drinking alcohol with this medicine can cause side effects.

Vecamyl side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • tremors or jerky muscle movements;

  • numbness, tingling, burning pain;

  • painful or difficult urination;

  • ongoing diarrhea with stomach bloating;

  • confusion, thinking problems;

  • a light-headed feeling, like you might pass out;

  • a seizure; or

  • dry cough, wheezing, feeling short of breath (even while lying down).

Common side effects may include:

  • dizziness or fainting;

  • nausea, vomiting, loss of appetite;

  • constipation;

  • dry mouth, swollen tongue;

  • feeling weak or tired;

  • blurred vision; or

  • impotence, decreased interest in sex.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Vecamyl?

When you start or stop taking Vecamyl, your doctor may need to adjust the doses of any other blood pressure medicines you take on a regular basis.

Tell your doctor about all your other medicines, especially:

  • an antibiotic; or

  • a diuretic or "water pill".

This list is not complete. Other drugs may affect Vecamyl, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

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.