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Generic Name: Carbamazepine
Brand Name(s): Tegretol
Information updated: April 1, 2000
Overview
Tegretol is prescribed for the control of a variety of seizure disorders.
It is also used as a special kind of pain reliever for trigeminal neuralgia which produces severe facial pain.
Although the Food and Drug Administration has not approved Tegretol for other uses, doctors sometimes prescribe it for a variety of psychiatric disorders, alcohol withdrawal and restless leg syndrome.
Side Effects and Interactions
Side effects associated with Tegretol include dizziness, drowsiness, incoordination, unsteadiness, mood changes, nausea, vomiting, stomachache and loss of appetite.
Other adverse reactions to be alert for include both diarrhea and constipation, rash, itching, urinary difficulties, headache, fatigue, blurred vision, ringing in the ears, numbness and tingling of the hands and feet, swollen legs and feet, heart failure, blood pressure problems, fainting, sexual problems, dehydration, unexplained sore throat with fever and chills, mouth ulcers, and aching joints and muscles.
Blood tests are needed to detect kidney failure, liver enzyme elevations, and blood disorders. Report any symptoms to your physician immediately.
A large number of over-the-counter and prescription medications may interact with Tegretol in a dangerous way.
Some drugs, such as Biaxin, erythromycin, Darvon or Darvocet DN 100, can make Tegretol much more toxic, with dangerous blood levels building up surprisingly quickly.
Other anticonvulsants interact with Tegretol in complicated ways and may even reduce its effectiveness.
In addition, Tegretol can interfere with the benefits of many other compounds.
Just a few of the many drugs that interact with Tegretol include several different kinds of antidepressant, the blood thinner Coumadin, the ulcer drug Tagamet, the heart and blood pressure pills Cardizem CD, Calan SR and Verelan, and certain antibiotics such as tetracycline, Vibramycin and INH.
Other medications that may cause problems include the asthma drug theophylline, Haldol, Sandimmune, Danocrine and even flu vaccine and activated charcoal.
It's possible that flavonoids found in the herb echinacea affect the enzyme (CYP 3A4) responsible for metabolizing many common drugs. If so, medications such as Tegretol could reach higher levels in the body.
The herb St. Jone's wort might speed elimination of Tegretol from the body, which could reduce its effectiveness.
Psyllium can affect the absorption of Tgretol; if you take it, it is best to do so at least an hour after taking Tegretol.
Do not take any other medications or herbs without first checking with your physician and pharmacist.
Special Precautions
Some people should not take Tegretol.
Elderly patients may be especially susceptible to side effects of confusion, agitation or even psychosis.
People with glaucoma, heart disease, kidney problems, liver damage, lupus or a history of blood disorders should take Tegretol only under close medical supervision, if at all.
This medicine can produce a dangerous anemia or blood disorder that can be life-threatening. Periodic blood tests, particularly during the first two months, are crucial to reduce the risk of this hazard.
Pregnant women should use Tegretol only after careful evaluation and discussions with an obstetrician.
Anticonvulsants in general have the potential to cause birth defects.
Taking the Medicine
Tegretol is best absorbed when it is taken with meals. This should also reduce the likelihood of stomach upset.
To maintain its effectiveness, this medicine should be stored in a tightly closed container away from heat and humidity.
Stopping it abruptly could lead to seizures and should be avoided.
Joe Graedon is a pharmacologist. Teresa Graedon holds a doctorate in medical anthropology and is a nutrition expert. Their syndicated radio show can be heard on public radio.
© 2000