TACRINE (Systemic)?
Some commonly used brand names are:
In the U.S.?
Other commonly used names are THAand tetrahydroaminoacridine.
? Not commercially available in Canada.
Category
- Dementia symptoms treatment adjunct
Description
Tacrine (TAK-reen) is used to treat the symptomsof mild to moderate Alzheimer's disease. Tacrine will not cure Alzheimer'sdisease, and it will not stop the disease from getting worse. However, tacrinecan improve thinking ability in some patients with Alzheimer's disease.
In Alzheimer's disease, many chemical changes take place in the brain.One of the earliest and biggest changes is that there is less of a chemicalmessenger called acetylcholine (ACh). ACh helps the brain to work properly.Tacrine slows the breakdown of ACh, so it can build up and have a greatereffect. However, as Alzheimer's disease gets worse, there will be less andless ACh, so tacrine may not work as well.
Tacrine may cause liver problems. While taking this medicine, you musthave blood tests regularly to see if the medicine is affecting your liver.
This medicine is available only with your doctor's prescription, in thefollowing dosage form:
Before Using This Medicine
In deciding to use a medicine,the risks of taking the medicine must be weighed against the good it willdo. This is a decision you and your doctor will make. For tacrine the followingshould be considered:
Allergies?Tell your doctor if you have ever had any unusual orallergic reaction to tacrine or to wound antiseptics (e.g., Akrinol, Panflavin,Monacrin). Also tell your health care professional if you are allergic toany other substances, such as foods, preservatives, or dyes.
Pregnancy?Studies on effects in pregnancy have not been donein either humans or animals.
Breast-feeding?It is not known whether tacrine passes into breastmilk. However, use of tacrine is not recommended in nursing mothers.
Children?Studies on this medicine have been done only inadult patients, and there is no specific information comparing use of tacrinein children with use in other age groups.
Older adults?Studies on tacrine have been done only in middle-agedand older patients. Information on the effects of tacrine is based on thesepatients.
Other medicines?Although certain medicines should not be usedtogether at all, in other cases two different medicines may be used togethereven if an interaction might occur. In these cases, your doctor may want tochange the dose, or other precautions may be necessary. When you are takingtacrine, it is especially important that your health care professional knowif you are taking any of the following:
- Cimetidine (e.g., Tagamet)?Cimetidine may cause higher bloodlevels of tacrine, which may increase the chance of side effects
- Inflammation or pain medicine, except narcotics?Stomach irritationmay be increased
- Neuromuscular blocking agents (medicines used in surgery to relaxmuscles)?Tacrine may increase the effects of these medicines; your doctormay change the dose of tacrine before you have surgery
- Smoking tobacco?Smoking may cause lower blood levels of tacrine,which may decrease the effects of tacrine; if you smoke, your doctor may needto change the dose of tacrine
- Theophylline (e.g., Theo-Dur, Uniphyl)?Tacrine may cause higherblood levels of theophylline, which may increase the chance of side effects;your doctor may need to change the dose of theophylline
Other medical problems?The presence of other medicalproblems may affect the use of tacrine. Make sure you tell your doctor ifyou have any other medical problems, especially:
- Asthma (or history of) or
- Heart problems, including slow heartbeat or hypotension (low bloodpressure), or
- Intestinal blockage or
- Liver disease (or history of) or
- Parkinson's disease or
- Stomach ulcer (or history of) or
- Urinary tract blockage or difficult urination?Tacrine may makethese conditions worse
- Brain disease, other, or
- Epilepsy or history of seizures or
- Head injury with loss of consciousness?Tacrine may cause seizures
Proper Use of This Medicine
Take this medicine only as directed by your doctor. Do not take moreor less of it, and do not take it more or less often than your doctor ordered.Taking too much may increase the chance of side effects, while taking toolittle may not improve your condition.
Tacrine is best taken on an empty stomach (1 hour before or 2 hours aftermeals). However, if this medicine upsets your stomach, your doctor may wantyou to take it with food.
Tacrine seems to work best when it is taken at regularly spaced times,usually four times a day.
Dosing?The dose of tacrine will be different for differentpatients. Follow your doctor's orders or the directionson the label. The following information includes only the average dosesof tacrine. If your dose is different, do not changeit unless your doctor tells you to do so.
- For oral dosage form (capsules):
- For treatment of Alzheimer's disease:
- Adults?To start, 10 milligrams (mg) four times a day. Yourdoctor may increase your dose gradually if you are doing well on this medicineand your liver tests are normal. However, the dose is usually not more than40 mg four times a day.
Missed dose?If you miss a dose of this medicine, take it assoon as possible. However, if it is within 2 hours of your next dose, skipthe missed dose and go back to your regular dosing schedule. Do not doubledoses.
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 otherdamp places. Heat or moisture may cause the medicine to break down.
- Do not keep outdated medicine or medicine no longer needed. Be surethat any discarded medicine is out of the reach of children.
Precautions While Using This Medicine
It is important that your doctor check your progress at regularvisits. Also, you must have your blood tested every other week forat least the first 4 to 16 weeks when you start using tacrine to see if thismedicine is affecting your liver. If all of the blood tests are normal, youwill still need regular testing, but then your doctor may decide to do thetests less often.
Tell your doctor if your symptoms get worse, or if you notice any new symptoms.
Before you have any kind of surgery, dental treatment, or emergency treatment,tell the medical doctor or dentist in charge that you are taking this medicine.Taking tacrine together with medicines that are sometimes used during surgeryor dental or emergency treatments may increase the effects of these medicines.
Tacrine may cause some people to become dizzy, clumsy, or unsteady. Makesure you know how you react to this medicine before you do anything that couldbe dangerous if you are dizzy, clumsy, or unsteady.
Do not stop taking this medicine or decrease your dosewithout first checking with your doctor. Stopping this medicine suddenlyor decreasing the dose by a large amount may cause mental or behavior changes.
If you think you or someone else may have taken anoverdose of tacrine, get emergency help at once. Taking an overdoseof tacrine may lead to seizures or shock. Some signs of shock are large pupils,irregular breathing, and fast weak pulse. Other signs of an overdose are severenausea and vomiting, increasing muscle weakness, greatly increased sweating,and greatly increased watering of the mouth.
Side Effects of This Medicine
Along with its needed effects,a medicine may cause some unwanted effects. Some side effects will have signsor symptoms that you can see or feel. Your doctor may watch for others bydoing certain tests
Tacrine may cause some serious side effects, including liver problems.You and your doctor should discuss the good this medicine will do as wellas the risks of receiving it.
Check with your doctoras soon as possible if any of the following side effects occur:
Rare
Aggression, irritability, or nervousness; change in stool color; convulsions (seizures); cough, tightness in chest, troubled breathing, or wheezing; stiffness of arms or legs, slow movement, or trembling and shakingof hands and fingers; trouble in urinating; yellow eyes or skin
Symptoms of overdose
Convulsions (seizures); greatly increasedsweating; greatly increased watering of mouth; increasing muscle weakness; low bloodpressure; nausea (severe); shock (fast weak pulse, irregular breathing, large pupils); slow heartbeat; vomiting (severe)
This medicine may also causethe following side effect that your doctor will watch for:
Other side effects may occur that usually donot need medical attention. These side effects may go away during treatmentas your body adjusts to the medicine. However, check with your doctor if anyof the following side effects continue or are bothersome:
Other side effects not listed above may also occur insome patients. If you notice any other effects, check with your doctor.
Revised: 11/19/1998
