Carbazin® CR is a preparation of carbamazepine. It is an anticonvulsant and specific analgesic for trigeminal neuralgia. It stabilizes hyperexcited nerve membranes, inhibits repetitive neuronal discharges, and reduces synaptic propagation of excitatory impulses. It is conceivable that prevention of repetitive firing of sodium-dependent action potentials in depolarized neurons is achieved via blockade of voltage-dependent sodium channels. As an antiepileptic agent its spectrum of activity embraces: partial seizures (simple and complex) with or without secondary generalization; generalized tonic-clonic seizures, or combinations of these types of seizures. Whereas reduction of glutamate release and stabilization of neuronal membranes may account for the antiepileptic effects, the depressant effect on dopamine and noradrenaline turnover could be responsible for the antimanic properties of carbamazepine.
 

Carbazin® CR is useful for the following conditions:
Epilepsy: Generalized tonic-clonic (grand mal) and partial seizures. It is indicated in newly diagnosed patients with epilepsy and in those patients who are uncontrolled or unable to tolerate their current anti-convulsant therapy.
[Note: Carbamazepine is not usually effective in absences (petit mal) and myoclonic seizures. Moreover, anecdotal evidence suggests that seizure exacerbation may occur in patients with atypical absences]
Treatment of the pain associated with trigeminal neuralgia. Beneficial results have also been reported in glossopharyngeal neuralgia. This drug is not a simple analgesic and should not be used for the relief of trivial aches or pains.
Treatment of Acute Mania and Prophylaxis in Bipolar (Manic-Depressive) Disorders of patients unresponsive to lithium therapy.
 

Carbazin® CR is an extended-release formulation for twice-a-day administration and is given orally. When converting patients from Carbazin® conventional tablets to Carbazin® CR, the same total daily mg dose of Carbazin® CR should be administered. Carbazin® CR tablets must be swallowed and never crushed or chewed. It should be swallowed with a little liquid, before, during or between meals. The divisible tablet presentation enables flexibility of dosing to be achieved. Carbazin® CR tablet coating is not absorbed and is excreted in the feces; these coatings may be noticeable in the stool.
Epilepsy

Adults and children over 12 years of age:
Initial: 200 mg twice a day of CR tablets. Dose is increased at weekly intervals by adding up to 200 mg CR tablet per day until the optimal response is obtained. Dosage generally should not exceed 1000 mg daily in children of 12 to 15 years of age, and 1200 mg daily in patients above 15 years of age. Doses up to 1600 mg daily have been used in adults in rare instances.
Maintenance: the dose is maintained at the minimum effective level, usually 800-1200 mg daily.
Children of 6 - 12 years of age:
Initial: 100 mg twice a day of CR tablets. Dose is increased at weekly intervals by adding up to 100 mg per day until the optimal response is obtained. Dosage generally should not exceed 1000 mg daily.
Maintenance: the dose is maintained at the minimum effective level, usually 400-800 mg daily.
Combination Therapy: Carbamazepine may be used alone or with other anticonvulsants. When added to existing anticonvulsant therapy, the drug should be added gradually while the other anticonvulsants are maintained or gradually decreased, except phenytoin, which may have to be increased.
Trigeminal Neuralgia
Initial: On the first day, 100 mg twice a day of CR tablets. This daily dose may be increased by up to 200 mg a day using increments of 100 mg every 12 hours by CR tablets, as needed to achieve freedom from pain. Dose should not exceed 1200 mg/daily.
Maintenance: Control of pain can be maintained in most patients with 400 mg to 800 mg daily. However, some patients may be maintained on as little as 200 mg daily, while others may require as much as 1200 mg daily. At least once every 3 months throughout the treatment period, attempts should be made to reduce the dose to the minimum effective level or even to discontinue the drug.
Mania and Bipolar (Manic-Depressive) Disorders:
Initially 200 to 400 mg/day, although higher starting doses of 400 to 600 mg/day may be used in acute mania. This dose may be gradually increased until patient symptomatology is controlled or a total daily dose of 1600 mg is achieved. Increments in dosage should be adjusted to provide optimal patient tolerability. The usual dose range is 400 to 1200 mg/day administered in divided doses. Doses used to achieve optimal acute responses and tolerability should be continued during maintenance treatment. When given in combination with lithium and neuroleptics, the initial dosage should be low, 100 to 200 mg daily, and then increased gradually. A dose higher than 800 mg/day is rarely required when given in combination with neuroleptics and lithium, or with other psychotropic drugs such as benzodiazepines. Plasma levels are probably not helpful for guiding therapy in bipolar disorders.

Carbamazepine should be prescribed only after a critical benefit-risk appraisal and under close monitoring in patients with a history of cardiac, hepatic or renal damage, adverse hematological reactions to other drugs or interrupted courses of therapy with carbamazepine. Baseline and periodic complete urinalysis and BUN determinations are recommended. Carbamazepine has shown mild anticholinergic activity; patients with increased intraocular pressure should therefore be warned and advised regarding possible hazards. The possibility of activation of a latent psychosis and in elderly patients, of confusion or agitation should be borne in mind.
 

It is contra-indicated in inflammatory bowel disease, severe congestive heart failure.
 

Use in pregnancy
Pregnant women with epilepsy should be treated with special care.
In women of childbearing age carbamazepine should, wherever possible, be prescribed as monotherapy, because the incidence of congenital abnormalities in the offspring of women treated with a combination of anti-epileptic drugs is greater than in those of mothers receiving the individual drugs as monotherapy. If pregnancy occurs in a woman receiving carbamazepine, or if the problem of initiating treatment with carbamazepine arises during pregnancy, the drug's potential benefits must be carefully weighed against its possible hazards, particularly in the first three months of pregnancy. Minimum effective doses should be given and monitoring of plasma levels is recommended. Offspring of epileptic mothers with untreated epilepsy are known to be more prone to developmental disorders, including malformations. There are reports on developmental disorders and malformations, including spina bifida, and also other congenital anomalies e.g. craniofacial defects, cardiovascular malformations and anomalies involving various body systems, have been reported in association with carbamazepine. Patients should be counselled regarding the possibility of an increased risk of malformations and given the opportunity of antenatal screening.
Folic acid deficiency is known to occur in pregnancy. Anti-epileptic drugs have been reported to aggravate deficiency. This deficiency may contribute to the increased incidence of birth defects in the offspring of treated epileptic women. Folic acid supplementation has therefore been recommended before and during pregnancy. Vitamin K1 to be given to the mother during the last weeks of pregnancy as well as to the newborn to prevent bleeding disorders in the offspring, has also been recommended. 

Use in lactation:
Carbamazepine passes into the breast milk (about 25-60% of the plasma concentrations). The benefits of breast-feeding should be weighed against the remote possibility of adverse effects occurring in the infant. Mothers taking carbamazepine may breast-feed their infants, provided the infant is observed for possible adverse reactions (e.g. excessive somnolence, allergic skin reaction).
 

Store in a cool and dry place, away from light. Keep out of reach of children.
 

Carbazin® CR tablet : Box containing 5 strips of 10 tablets each. Each controlled-release tablet contains carbamazepine USP 200 mg. 



Manufactured by:
ESKAYEF BANGLADESH LTD
DHAKA, BANGLADESH
® REGD.TRADEMARK