In the U.S.—

• Antihypertensive

Mecamylamine (mek-a-MILL-a-meen) belongs to the general class of medicines called antihypertensives. It is used to treat high blood pressure (hypertension).

High blood pressure adds to the workload of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly. This can damage the blood vessels of the brain, heart, and kidneys, resulting in a stroke, heart failure, or kidney failure. High blood pressure may also increase the risk of heart attacks. These problems may be less likely to occur if blood pressure is controlled.

Mecamylamine works by controlling impulses along certain nerve pathways. As a result, it relaxes blood vessels so that blood passes through them more easily. This helps to lower blood pressure.

Mecamylamine is available only with your doctor's prescription, in the following dosage form:

Oral
• Tablets (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For mecamylamine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to mecamylamine. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Studies on effects in pregnancy have not been done in either humans or animals. However, in general, use of this medicine during pregnancy is not recommended because pregnant women may be more sensitive to its effects. In addition, mecamylamine may cause bowel problems in the unborn baby.

Breast-feeding—It is not known whether mecamylamine passes into breast milk. However, this medicine has not been reported to cause problems in nursing babies.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of mecamylamine in children with use in other age groups.

Older adults—Dizziness or lightheadedness may be more likely to occur in the elderly, who are more sensitive to the effects of mecamylamine.

Other medicines—Although certain medicines should not be used together at all, in many cases two different medicines may be used together even if an interaction might occur. In these cases, changes in dose or other precautions may be necessary. When taking mecamylamine it is especially important that your health care professional know if you are taking any of the following:

• Antibiotics or
• Sulfonamides (sulfa medicine)—Patients with chronic pyelonephritis being treated with these medications should not be treated with mecamylamine

• Antimyasthenics (ambenonium [e.g., Mytelase], neostigmine [e.g., Prostigmin], pyridostigmine [e.g., Mestinon])—Effects of these medicines may be decreased by mecamylamine

• Urinary alkalizers (medicine that makes the urine less acid, such as acetazolamide [e.g., Diamox], calcium- and/or magnesium-containing antacids, dichlorphenamide [e.g., Daranide], methazolamide [e.g., Neptazane], potassium or sodium citrate and/or citric acid, sodium bicarbonate [baking soda])—Effects of mecamylamine may be increased because these medicines cause it to be removed more slowly from the body

• Bladder or prostate problems—Mecamylamine may interfere with urination

• Bowel problems—Patients with bowel problems who take mecamylamine may be at increased risk for serious bowel side effects of mecamylamine

• Diarrhea or
• Fever or infection or
• Nausea or vomiting—Effects of mecamylamine on blood pressure may be increased

• Glaucoma—Mecamylamine may make this condition worse

• Heart or blood vessel disease or
• Heart attack or stroke (recent)—Lowering of blood pressure by mecamylamine may make problems resulting from these conditions worse

• Kidney disease—Effects of mecamylamine may be increased because of slower removal of mecamylamine from the body

In addition to the use of the medicine your doctor has prescribed, treatment for your high blood pressure may include weight control and care in the types of foods you eat, especially foods high in sodium. Your doctor will tell you which of these are most important for you. You should check with your doctor before changing your diet.

Many patients who have high blood pressure will not notice any signs of the problem. In fact, many may feel normal. It is very important that you take your medicine exactly as directed and that you keep your appointments with your doctor even if you feel well.

Remember that this medicine will not cure your high blood pressure but it does help control it. Therefore, you must continue to take it as directed if you expect to lower your blood pressure and keep it down. You may have to take high blood pressure medicine for the rest of your life . If high blood pressure is not treated, it can cause serious problems such as heart failure, blood vessel disease, stroke, or kidney disease.

To help you remember to take your medicine, try to get into the habit of taking it at the same time each day.

Dosing—

The dose of mecamylamine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of mecamylamine. If your dose is different, do not change it unless your doctor tells you to do so:

• For oral dosage forms (tablets):
  • Adults: 2.5 milligrams two times a day to 25 milligrams three times a day.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. Then go back to your regular dosing schedule. If you miss two or more doses in a row, check with your doctor right away . If your body goes without this medicine for too long, your blood pressure may go up to a dangerously high level.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

It is important that your doctor check your progress at regular visits to make sure that this medicine is working properly.

Check with your doctor before you stop taking this medicine. Your doctor may want you to reduce gradually the amount you are taking before stopping completely.

Make sure that you have enough medicine on hand to last through weekends, holidays, or vacations. You should not miss taking any doses. You may want to ask your doctor for another written prescription for mecamylamine to carry in your wallet or purse. You can then have it filled if you run out of medicine when you are away from home.

Do not take other medicines unless they have been discussed with your doctor. This especially includes over-the-counter (nonprescription) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, since they may tend to increase your blood pressure.

Dizziness, lightheadedness, or fainting may occur, especially when you get up from a lying or sitting position. This is more likely to occur in the morning. Getting up slowly may help. When you get up from lying down, sit on the edge of the bed with your feet dangling for one or two minutes. Then stand up slowly. If you feel dizzy, sit or lie down. If the problem continues or gets worse, check with your doctor.

The dizziness, lightheadedness, or fainting is also more likely to occur if you drink alcohol, stand for a long time, exercise, or if the weather is hot. While you are taking this medicine, be careful to limit the amount of alcohol you drink. Also, use extra care during exercise or hot weather or if you must stand for a long time.

Sodium bicarbonate (commonly known as baking soda) may cause you to get a greater than normal effect from this medicine. To prevent problems, check with your health care professional before using an antacid or medicine for heartburn since some of these contain sodium bicarbonate.

Tell your doctor if you get a fever or infection since that may change the amount of medicine you have to take.

Mecamylamine may cause dryness of the mouth, nose, and throat. For temporary relief of mouth dryness, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking this medicine.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Dizziness or lightheadedness, especially when getting up from a lying or sitting position 
  
  

• Less common
  • Difficult urination 
  
  

• Rare
  • Bloating and frequent loose stools;  confusion or excitement;  constipation (severe);  convulsions (seizures);  mental depression ;  shortness of breath;  trembling;  uncontrolled movements of face, hands, arms, or legs 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Constipation;  drowsiness;  unusual tiredness 
  
  

• Less common or rare
  • Blurred vision;  decreased sexual ability or interest in sex;  dryness of mouth;  enlarged pupils;  loss of appetite;  nausea and vomiting;  weakness 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.