mecamylamine
Mecamylamine, also known by its brand name Vecamyl, is an older prescription medication that's FDA approved to treat moderately severe to severe high blood pressure and some cases of life-threatening high blood pressure. It comes as a tablet that's taken by mouth up to 3 times a day. Mecamylamine (Vecamyl) isn't commonly used anymore because it has many side effects and newer, safer blood pressure medications are now available. It can also interact with several medications. Side effects include dizziness, constipation, and blurry vision.
What is Mecamylamine (Vecamyl)?
What is Mecamylamine (Vecamyl) used for?
- Moderately severe to severe high blood pressure
- Life-threatening high blood pressure without complications
How Mecamylamine (Vecamyl) works
Mecamylamine (Vecamyl) is a ganglion blocker. It works by locking nerve singles that use a chemical called acetylcholine. This helps relax your blood vessels and reduces how hard your heart works, which lowers your blood pressure.
Drug facts
Side effects of Mecamylamine (Vecamyl)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
- Dizziness
- Fainting
- Lightheadedness
- Tiredness
Less Common Side Effects
- Blurry vision
- Dry mouth
- Constipation
- Nausea
- Vomiting
- Trouble urinating
- Reduced sex drive
Mecamylamine (Vecamyl) serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Nervous system side effects: seizures, confusion, tremors, involuntary movements, changes in thinking
- Intestinal blockage: frequent diarrhea, stomach bloating, less stomach rumbling
The following Mecamylamine (Vecamyl) side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Constipation, bloating, nausea or vomiting, stomach pain, which may be signs of slow movement through the digestive tract
- Low blood pressure—dizziness, feeling faint or lightheaded, blurry vision
- New or worsening uncontrolled and repetitive movements of the face, mouth, or upper body
- Tremors or shaking
- Trouble passing urine
- Unusual changes in behavior
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
Pros and cons of Mecamylamine (Vecamyl)
Pros
- Works within 30 minutes to 2 hours
- Can last for up to 12 hours or more
- Taken by mouth
Cons
- Not a first-choice option to treat severe high blood pressure
- Commonly causes dizziness, blurred vision, and constipation
- Might need to take three times per day
Pharmacist tips for Mecamylamine (Vecamyl)
- Take mecamylamine (Vecamyl) by mouth with or without food. Taking it after meals can help your body absorb the medication more gradually for smoother blood pressure control. But it's more important to take it the same way each time — either always with food or always without.
- Take mecamylamine (Vecamyl) exactly as prescribed. Don't change your dose or stop taking it suddenly without talking to your prescriber. Doing so can cause your blood pressure to rise quickly. Your prescriber might need to lower your dose gradually before you stop taking it completely.
- Check your blood pressure at home regularly and write down your readings. Share these with your prescriber during follow-up visits to see if the medication is working for you and if your treatment plan needs adjustments.
- Mecamylamine (Vecamyl) can cause dizziness and lightheadedness, especially when you first start taking the medication or when your dose is raised. To prevent falls, stand up slowly after sitting or lying down.
- Ask your prescriber if a low-salt diet is right for you. Eating less salt can make mecamylamine (Vecamyl) work stronger. Tell your prescriber if you have diarrhea, vomiting, heavy sweating, or take diuretics (water pills), as these can lower your body’s salt levels.
- Mecamylamine (Vecamyl) can interact with many medications. Be sure to tell your care team about all the medications you’re taking before and during treatment, especially if you take other medications that lower your blood pressure.
- It's best to avoid alcohol with mecamylamine (Vecamyl) because it can lower your blood pressure, causing dizziness and falls. It can also worsen side effects like sleepiness, dizziness, and blurry vision.
- Let your prescriber know your exercise routine and report any infections, fevers, or bleeding during treatment with mecamylamine (Vecamyl). These can make the medication’s effects stronger and raise your risk of side effects.
- If you experience repeated diarrhea or stomach bloating after starting mecamylamine (Vecamyl), contact your prescriber right away. This could be a sign of a serious bowel issue.
- If you're pregnant, thinking of getting pregnant, or breastfeeding and are taking mecamylamine (Vecamyl), let your prescriber know. They might recommend other medications that are safer during pregnancy or breastfeeding.
Common questions about Mecamylamine (Vecamyl)
Yes, mecamylamine (Vecamyl) causes vasodilation, which means it helps widen blood vessels. It does so by blocking signals in the nervous system that cause blood vessels to tighten. By relaxing the blood vessels, mecamylamine (Vecamyl) helps to lower blood pressure.
It's not completely clear if mecamylamine (Vecamyl) helps with quitting smoking because there isn't strong evidence. It isn't FDA approved for smoking cessation, but it has been studied since it blocks nicotinic receptors — the same receptors nicotine attaches to cause addiction. A 1998 study suggested that mecamylamine (Vecamyl) might help with smoking cessation, especially when combined with nicotine replacement therapy. But a 2018 study didn't find clear benefits. If you're trying to quit smoking, talk to your care team about the best treatment options.
No, mecamylamine (Vecamyl) isn't addictive or habit-forming, which means you won’t develop a dependency on it. It’s also not classified as a controlled substance.
Mecamylamine (Vecamyl) starts lowering blood pressure within 30 minutes to 2 hours. It also typically lasts 6 to 12 hours, but for some people, the effects might last even longer.
Yes, though not very often. Mecamylamine (Vecamyl) is still FDA approved to treat severe high blood pressure. But it has many bothersome side effects, such as dizziness, constipation, dry mouth, and blurred vision. Newer and safer medications are also now available. Speak to your prescriber if you have questions about this medication.
How to save using GoodRx
Risks and warnings for Mecamylamine (Vecamyl)
Mecamylamine (Vecamyl) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Nervous system side effects
- Risk factors: Taking higher doses of mecamylamine (Vecamyl) | Kidney problems | Brain problems
Mecamylamine (Vecamyl) can reach the brain and can cause nervous system side effects, though these are rare. They're more likely to happen if you have kidney problems or certain brain conditions. Get medical help if you have convulsions (sudden shaking), as this could be a sign of a seizure. Let your prescriber know right away if you experience confusion, tremors, or involuntary movements.
Sudden high blood pressure after stopping
If you stop taking ganglion blockers like mecamylamine (Vecamyl) suddenly, your blood pressure can rise to dangerous levels. This sudden change can cause serious problems, such as a stroke or heart failure. To prevent this, your prescriber will gradually lower your dose of mecamylamine (Vecamyl) and usually switch you to another blood pressure medication. Always follow your prescriber’s instructions when stopping or changing medications.
Low blood pressure
- Risk factors: Problems with blood flow in the body | Excessive heat | Fever | Infection | Bleeding | Pregnancy | Anesthesia and surgery | Intense exercise | Alcohol use | Taking other blood pressure medications | Low salt levels in your body | Excessive sweating | Having diarrhea or vomiting
Taking mecamylamine (Vecamyl) can sometimes lower your blood pressure too much. This might happen more easily in certain situations, like being in excessive heat, having a fever or infection, bleeding, pregnancy, anesthesia, surgery, intense exercise, drinking alcohol, or taking other blood pressure medications. Make sure to stay well-hydrated. If your blood pressure drops too low and you feel dizzy, sit down slowly and hold onto something stable. Contact your care team if this happens. If you fall and hit your head, get medical help right away.
Trouble urinating
- Risk factors: Enlarged prostate | Bladder problems
Mecamylamine (Vecamyl) can cause trouble urinating (urinary retention). The risk is higher if you have conditions like an enlarged prostate or bladder problems. Let your prescriber know if you have symptoms such as difficulty passing urine, urgency, or weak urine stream.
Intestinal blockage
Frequent diarrhea, stomach bloating, and less stomach rumbling could be early signs of an intestinal blockage while taking mecamylamine (Vecamyl). If you experience these symptoms, stop the medication and let your prescriber know right away.
Mecamylamine (Vecamyl) dosage
Typical dosage for Mecamylamine (Vecamyl)
The typical starting dose is 2.5 mg by mouth twice a day. Your prescriber will raise the dose slowly over a few weeks. Most people take 25 mg per day, which is typically split up into three smaller doses throughout the day.
Mecamylamine (Vecamyl) contraindications
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Mecamylamine (Vecamyl) will not be safe for you to take.
- Mild or moderate high blood pressure
- Recent heart attack or coronary artery disease
- Uremia (a serious kidney condition)
- Taking antibiotics and sulfonamides
- Glaucoma
- Pyloric stenosis (narrowing of the opening from the stomach to the intestines)
