Carbamazepine

Brand names

• Apo-Carbamazepine
• Carbitrol Extended Release
• Dom-Carbamazepine-CR
• Epitol
• Gen-Carbamazepine
• Mazepine
• Novo-Carbamaz
• Nu-Carbamazepine
• PMS Carbamazepine
• Taro-Carbamazepine
• Tegretol
• Tegretol Chewable Tablet
• Tegretol-CR
• Tegretol-XR

Usage

To control certain types of seizures due to epilepsy. Also to treat facial pain in those with trigeminal neuralgia (tic douloureux). To treat bipolar disorder and acute mania.

How it works

Carbamazepine appears to inhibit neurons from firing repeatedly and uncontrollably (which causes seizures).

Side effects

Serious

Fever, sore throat, swollen glands, point-like rash, blistering or peeling, easy bruising, pallor, weakness, confusion, lethargy, or seizures may be a sign of a potentially fatal blood reaction (aplastic anemia).

Common

Drowsiness, rash, itching, increased sensitivity of the skin to sunlight, dizziness, blurred vision, incoordination, nausea, vomiting, stomach pain or upset, diarrhea, constipation, loss of appetite, dry or inflamed mouth.

Less common

Impaired speech; involuntary movements of the face, limbs, or tongue; tingling or numbness in the extremities; depression; agitation; psychosis; talkativeness; abnormal eye movements; ringing in the ears; heart rhythm abnormalities; impotence; hair loss; or excessive hair growth. There are numerous additional potential side effects.

Possible interactions

Other medicaments:

Carbamazepine may increase the effects of:

• sedatives, tranquilizers, hypnotics and narcotics, and enhance their sedative effects.

Carbamazepine may decrease the effects of:

• adrenocortical steroids.
• alprazolam (Xanax).
• amprenavir (Agenerase).
• antidepressants.
• bupropion (Wellbutrin, Zyban).
• corticosteroids (such as prednisone or cortisone).
• cyclosporine (Sandimmune).
• doxycycline (Doxy-II, Vibramycin, etc.).
• felodipine (Plendil).
• haloperidol (Haldol) or other phenothiazines.
• isradipine (DynaCirc).
• lamotrigine (Lamictal).
• midazolam (Versed).
• nelfinavir (Viracept).
• olanzapine (Zyprexa).
• tetracyclines.
• tramadol (Ultram) and cause loss of tramadol efficacy.
• valproic acid (Depakene, etc.).
• vincristin (Oncovin).
• warfarin (Coumadin). Increased frequency of INR testing is indicated.

Carbamazepine taken concurrently with:

• acetaminophen (Tylenol, others) may increase risk of acetaminophen liver toxicity.
• birth control pills (oral contraceptives) may lower blood levels of the birth control pills and result in pregnancy.
• chlorpromazine (Thorazine) solution may form a rubbery orange precipitate that is passed in the stool. Do not combine.
• cisplatin (Platinol, others).
• clozapine (Clozaril) may result in serious bone marrow suppression.
• delavirdine (Rescriptor) may lower trough levels of delavirdine.
• doxorubicin (Doxil, others).
• felbamate (Felbatol) may result in decreased carbamazepine levels and seizures.
• itraconazole (Sporanox) may cause loss of itraconazole benefits.
• ketorolac (Toradol) may blunt carbamazepine benefits.
• lithium (Lithobid, others) may cause serious neurological problems: confusion, drowsiness, weakness, unsteadiness, tremors and twitching.
• monoamine oxidase (MAO) type A inhibitor medicaments may cause severe toxic reactions.
• N-acetylcysteine (various) may blunt seizure control.
• phenytoin (Dilantin, etc.) and fosphenytoin (Cerebyx) may cause unpredictable fluctuations of blood levels of both medicaments and impair seizure control.
• primidone (Mysoline) may blunt carbamazepine effectiveness.
• sildenafil (Viagra) may result in changes in blood levels.
• terfenadine (Seldane), and perhaps other nonsedating antihistamines, may result in carbamazepine toxicity.
• theophylline (Theo-Dur, etc.) may reduce the effects of both medicaments.
• thioridazine (Mellaril) solution may form a rubbery orange precipitate that is passed in the stool. Do not combine.

The following medicaments may increase the effects of carbamazepine:

• cimetidine (Tagamet).
• danazol (Danocrine).
• diltiazem (Cardizem)-and perhaps other calcium channel blockers.
• flu shots (influenza vaccine).
• fluoxetine (Prozac); may lead to toxicity.
• fluvoxamine (Luvox); may result in toxicity.
• isoniazid (INH).
• ketoconazole (Nizoral) and fluconazole (Diflucan).
• macrolide antibiotics-erythromycins, clarithromycin or troleandomycin (not azithromycin).
• nefazodone (Serzone).
• nicotinamide (nicotinic acid amide).
• omeprazole (Prilosec).
• propoxyphene (Darvon, Darvocet, etc.).
• rifampin; may result in toxicity.
• ritonavir (Norvir) and perhaps other protease inhibitors such as amprenavir (Agenerase).
• verapamil (Calan, Isoptin).

Herbal medicines or minerals:

Using kola or ma huang may result in unacceptable central nervous system stimulation. Since part of the way that ginseng may work is as an MAO inhibitor, combination with this medicine is not recommended. Valerian and kava kava may interact to increase drowsiness. St. John's wort may also cause increased sun sensitivity - caution is advised.

Exposure to sun:

This medicament can cause photosensitivity. Use caution until sensitivity to sun is known.

Heavy exercise or exertion:

Use caution if you have coronary artery disease. Can intensify angina and reduce tolerance for physical activity.

Discontinuation:

If treating trigeminal neuralgia, attempts to reduce the maintenance dose or to stop this medicament are needed every 3 months. If used to control epilepsy, this medicament must not be stopped abruptly.

Special storage instructions:

Store tablets in a cool, dry place. Protect from humid conditions (do not store in a bathroom medicine cabinet) as this can decrease potency of both brand or generic forms by serious percentages.

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