Carbamazepine Pharmacology


About Carbamazepine
Tricyclic anticonvulsant , iminostilbene derivative, anticonvulsant , in trigeminal neuralgia.
Mechanism of Action of Carbamazepine
Carbamazepine prolongs the inactivated state of voltage sensitive neuronal sodium ion channel either by increasing the efflux or decreasing the influx of sodium ion across the cell membrane and inhibits the high frequency discharge.
It blocks the repetitive impulses that trigger seizures.
Carbamazepine modifies electroshock seizure and raises threshold to Pentylenetetrazole and electroshock convulsion. Carbamazepine is also used in mania and bipolar disorders.
Pharmacokinets of Carbamazepine
Absorption: Carbamazepine is slowly absorbed after oral administration. Distribution: It is distributed widely in the body in protein bound form. Metabolism: It is metabolised in the liver by oxidation to an active metabolite 10, 11 Epoxycarbamazepine. Excretion: Excreted mainly in urine and small amount in faeces.
Onset of Action for Carbamazepine
within 4 hours
Duration of Action for Carbamazepine
12 - 24 hours
Half Life of Carbamazepine
Side Effects of Carbamazepine
7.Epigastric distress
8.Blurred vision
9.Urine retention
10.Aplastic anaemia
12.Lupus like syndrome
Contra-indications of Carbamazepine
1.Hypersensitivity to Carbamazepine or known sensitivity to any of the Tricyclic antidepressants
2.History of bone marrow suppression
3.With or within 2 weeks of MAO inhibitor therapy
Special Precautions while taking Carbamazepine
1.Hepatic impairment
2.Renal impairment
3.Cardiac disease
4.Slowly withdraw the drug with caution
Pregnancy Related Information
Old Age Related Information
Use with caution
Breast Feeding Related Information
Children Related Information
Use with caution
Indications for Carbamazepine
1.Anticonvulsant(Generalised tonic-clonic seizure, complex partial seizure, Grand mal epilepsy, Psychomotor epilepsy)
2.Trigeminal neuralgia
3.Manic depressive illness (Bipolar disorders)
4.Acute mania
Interactions for Carbamazepine
Increased serum level of carbamazepine leading to toxicity (headache, dizziness, ataxia and nausea) by the following drugs:
Cimetidine, Danazol, Diltiazen, Erythromycin, Isoniazid, Nicotinamide, Propoxyphene, Verapamil.
Acetaminophen: Increases hepatotoxicity of acetaminophen.
Oral anticoagulants: Decreases efficacy of anit-coagulants.
Barbiturates, Primidone: Decrease serum levels of carbamazepine, but there is no loss of seizure control.
Charcoal: Decreases GI absorpion of carbamazepine.
Doxycycline: Half-life reduced.
Haloperidol: Efficacy decreased.
Hydantoins: Serum levels decreased.
Lithium: Increased CNS toxicity.
Nondepolarising Muscle Relaxants: Reversal of neuromuscular blockade.
Post-pituitary Hormones - Vasopressin, Lypressin, Desmopressin: Antidiuretic effect potentiated.
Theophylline: Efficacy of both decreased.
Alcohol: Tolerance to alcohol reduced.
Lab Tests: Thyroid Function test show decreased values.
Typical Dosage for Carbamazepine
Adults: 100 - 200 mg 2 times daily if needed dose can be increased by 200 mg / day in every 7 days until therapeutic response is obtained.
Maintenance dose: 800 - 1200 mg / day
Maximum dose: 1600 mg / day
Trigeminal neuralgia: initial dose 200 mg / day in 2 divided dose. From second day onwards increase the dose by 100 mg every 12 hours until pain is relieved.
Maximum dose: 1.2 g / day
Manic depressive illness and acute mania: 400mg / day in 2 divided doses. Dose can be gradually increased every 3 - 4 days until therapeutic response is obtained.
Maintenance dose: 600 - 1600 mg / day in divided doses
11-15 years: 600mg / day in divided doses
6 - 10 years: 400 - 600mg/day in divided doses
1- 5 years: 200 - 400mg/day in divided doses
< 1 year: 100 - 200 mg / day in divided doses
Above 12years: 100 - 200 mg 2 times daily with food if needed dose can be increased by 200 mg / day in every 7 days until therapeutic response is obtained.
Maintenance dose: 800 - 1200 mg / day
Maximum dose: 1600 mg / day
6 - 12 years: 100 mg in 2 divided doses with food then gradually increases the dose by 100 mg /day until sufficient response is obtained.
Maximum dose: 1000 mg / day
Schedule of Carbamazepine
Storage Requirements for Carbamazepine
Store at 15 - 30 degree C. Protect from light and moisture. Keep out of the reach of children.
Effects of Missed Dosage of Carbamazepine
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Carbamazepine
Give supportive measures and symptomatic treatment. Gastric lavage can be done to remove the drug from the body. To reduce the absorption of the drug activated charcoal can be given to the patient. Maintain fluid and electrolyte balance. Seizure should be controlled by administration of parenteral Diazepam or Barbiturates but they may exacerbate respiratory depression.

Home Delivery for Carbamazepine in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including carbamazepine.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for carbamazepine and other medicines and health products. Home delivery services for carbamazepine may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take carbamazepine only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for carbamazepine before they complete the sale. You can get this information while placing the order for carbamazepine with the pharmacy.

Carbamazepine is a generic medicine name and there are several brands available for it. Some of the brands for carbamazepine might be better known than carbamazepine itself. If the pharmacy that's willing to deliver medicines to your home doesn't have carbamazepine in stock, you can ask for one of the branded alternatives for carbamazepine.