Carbatrol (carbamazepine) - 2 indications

Scroll down for more information on each indication:

• Seizure disorders, including partial complex seizures, generalized tonic-clonic seizures (grand mal) and mixed seizures
• The treatment of the pain associated with true trigeminal neuralgia

General Information

Carbatrol (carbamazepine) is an anticonvulsant and specific analgesic.

Carbatrol is specifically indicated for the following:

• Seizure disorders, including:
  • Partial seizures with complex symptomatology (psychomotor, temporal lobe)
  • Generalized tonic-clonic seizures (grand mal)
  • Mixed seizure patterns which include the above, or other partial or generalized seizures
• The treatment of the pain associated with true trigeminal neuralgia

Carbatrol is supplied as an extended release tablet. Scroll down for the recommended dosing/administration for each indication.

Mechanism of Action

Carbamazepine has demonstrated anticonvulsant properties in rats and mice with electrically and chemically induced seizures. It appears to act by reducing polysynaptic responses and blocking the post-tetanic potentiation. Carbamazepine greatly reduces or abolishes pain induced by stimulation of the infraorbital nerve in cats and rats. It depresses thalamic potential and bulbar and polysynaptic reflexes, including the linguomandibular reflex in cats. Carbamazepine is chemically unrelated to other anticonvulsants or other drugs used to control the pain of trigeminal neuralgia. The mechanism of action remains unknown.

Side Effects

Adverse effects associated with the  use of Carbatrol may include, but are not limited to, the following:

• dizziness
• drowsiness
• unsteadiness
• nausea
• vomiting

The Carbatrol drug label comes with the following Black Box Warning: 

SERIOUS DERMATOLOGIC REACTIONS AND HLA-B*1502 ALLELE SERIOUS AND SOMETIMES FATAL DERMATOLOGIC REACTIONS, INCLUDING TOXIC EPIDERMAL NECROLYSIS (TEN) AND STEVENS-JOHNSON SYNDROME (SJS), HAVE BEEN REPORTED DURING TREATMENT WITH CARBAMAZEPINE. THESE REACTIONS ARE ESTIMATED TO OCCUR IN 1 TO 6 PER 10,000 NEW USERS IN COUNTRIES WITH MAINLY CAUCASIAN POPULATIONS, BUT THE RISK IN SOME ASIAN COUNTRIES IS ESTIMATED TO BE ABOUT 10 TIMES HIGHER. STUDIES IN PATIENTS OF CHINESE ANCESTRY HAVE FOUND A STRONG ASSOCIATION BETWEEN THE RISK OF DEVELOPING SJS/TEN AND THE PRESENCE OF HLA-B*1502, AN INHERITED ALLELIC VARIANT OF THE HLA-B GENE. HLAB*1502 IS FOUND ALMOST EXCLUSIVELY IN PATIENTS WITH ANCESTRY ACROSS BROAD AREAS OF ASIA. PATIENTS WITH ANCESTRY IN GENETICALLY AT-RISK POPULATIONS SHOULD BE SCREENED FOR THE PRESENCE OF HLA-B*1502 PRIOR TO INITIATING TREATMENT WITH CARBATROL . PATIENTS TESTING POSITIVE FOR THE ALLELE SHOULD NOT BE TREATED WITH CARBATROL® UNLESS THE BENEFIT CLEARLY OUTWEIGHS THE RISK.

APLASTIC ANEMIA AND AGRANULOCYTOSIS APLASTIC ANEMIA AND AGRANULOCYTOSIS HAVE BEEN REPORTED IN ASSOCIATION WITH THE USE OF CARBAMAZEPINE. DATA FROM A POPULATION-BASED CASECONTROL STUDY DEMONSTRATE THAT THE RISK OF DEVELOPING THESE REACTIONS IS 5-8 TIMES GREATER THAN IN THE GENERAL POPULATION. HOWEVER, THE OVERALL RISK OF THESE REACTIONS IN THE UNTREATED GENERAL POPULATION IS LOW, APPROXIMATELY SIX PATIENTS PER ONE MILLION POPULATION PER YEAR FOR AGRANULOCYTOSIS AND TWO PATIENTS PER ONE MILLION POPULATION PER YEAR FOR APLASTIC ANEMIA. ALTHOUGH REPORTS OF TRANSIENT OR PERSISTENT DECREASED PLATELET OR WHITE BLOOD CELL COUNTS ARE NOT UNCOMMON IN ASSOCIATION WITH THE USE OF CARBAMAZEPINE, DATA ARE NOT AVAILABLE TO ESTIMATE ACCURATELY THEIR INCIDENCE OR OUTCOME. HOWEVER, THE VAST MAJORITY OF THE CASES OF LEUKOPENIA HAVE NOT PROGRESSED TO THE MORE SERIOUS CONDITIONS OF APLASTIC ANEMIA OR AGRANULOCYTOSIS. BECAUSE OF THE VERY LOW INCIDENCE OF AGRANULOCYTOSIS AND APLASTIC ANEMIA, THE VAST MAJORITY OF MINOR HEMATOLOGIC CHANGES OBSERVED IN MONITORING OF PATIENTS ON CARBAMAZEPINE ARE UNLIKELY TO SIGNAL THE OCCURRENCE OF EITHER ABNORMALITY. NONETHELESS, COMPLETE PRETREATMENT HEMATOLOGICAL TESTING SHOULD BE OBTAINED AS A BASELINE. IF A PATIENT IN THE COURSE OF TREATMENT EXHIBITS LOW OR DECREASED WHITE BLOOD CELL OR PLATELET COUNTS, THE PATIENT SHOULD BE MONITORED CLOSELY. DISCONTINUATION OF THE DRUG SHOULD BE CONSIDERED IF ANY EVIDENCE OF SIGNIFICANT BONE MARROW DEPRESSION DEVELOPS.

Indication 1 - Seizure disorders, including partial complex seizures, generalized tonic-clonic seizures (grand mal) and mixed seizures

Approved 1997

Dosing/Administration

Adult dosage (ages 18 years and older)

• First dose: 200 mg taken 2 times per day.
• Typical dosage: 800–1,200 mg per day.
• Dosage changes: Each week, your doctor may increase your daily dose by 200 mg.
• Maximum dosage: 1,600 mg per day.

Child dosage (ages 12 to 17 years)

• First dose: 200 mg taken 2 times per day.
• Typical dosage: 800–1,200 mg per day.
• Dosage changes: Each week, your child’s doctor may increase their daily dose by 200 mg.
• Maximum dosage:
  • ages 12 to 15 years: 1,000 mg per day.
  • 15 years and older: 1,200 mg per day.

Child dosage (ages 6 to 12 years)

• First dose: 100 mg taken 2 times per day.
• Typical dosage: 400–800 mg per day.
• Dosage changes: Each week, your child’s doctor may increase their daily dose by 100 mg.
• Maximum dosage: 1,000 mg per day.

Child dosage (ages 0 to 5 years)

• First dose: 10–20 mg/kg per day. The dosage should be divided and taken 2–3 times each day.
• Dosage changes: Your child’s doctor may increase their dosage weekly.
• Maximum dosage: 35 mg/kg per day.

Clinical Trial Results

In controlled clinical trials, carbamazepine has been shown to be effective in the treatment of psychomotor and grand mal seizures, as well as trigeminal neuralgia.

Indication 2- The treatment of the pain associated with true trigeminal neuralgia

Dosing/Administration

Adult dosage (ages 18 years and older)

• First dose: 100 mg taken 2 times per day.
• Typical dosage: 400–800 mg per day.
• Dosage changes: Your doctor may increase your dosage by 100 mg every 12 hours.
• Maximum dosage: 1,200 mg per day.

Clinical Trial Results

In controlled clinical trials, carbamazepine has been shown to be effective in the treatment of psychomotor and grand mal seizures, as well as trigeminal neuralgia.