Carbamazepine

Carbamazepine(中文: 卡馬西平) is an anticonvulsant medication used primarily in the treatment of epilepsy and neuropathic pain. Carbamazepine appears to work as well as phenytoin and valproate for focal and generalized seizures. It is not effective for absence or myoclonic seizures. It is used in schizophrenia and as a second-line agent in the management of bipolar disorder unresponsive to lithium.

Drug Names

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Carbamazepine Suspension 100mg/5ml	CARB49	P1S1S3

Mechanism of Action

Anticonvulsant medication. It is a sodium channel blocker. It binds to sodium channels and suppresses repetitive neuronal firing.

Dosage

Epilepsy	Oral: initially 100 – 200 mg 1-2 times daily, increased slowly by increments of up 200 mg daily every week to an usual maintenance dose of 0.8 – 1.2 g daily in divided doses; up to 2 g daily may occasionally be necessary. By rectum: for short-term use (Max. 7 days) when oral therapy temporarily not possible; 125-mg suppository approximately equivalent to 100-mg tablet, but final adjustment should always depend on clinical response. Max. 1 g daily in 4 divided doses. Elderly: reduce initial dose. Child: the usual daily dose may be given according to age as follows: Up to 1 year: 100 to 200 mg 1 to 5 years: 200 to 400 mg 5 to 10 years: 400 to 600 mg 10 to 15 years: 0.6 to 1 g Over 15 years: usual adult doses The maximum recommended daily dose, according to age, is as follows: Up to 6 years: 35 mg/kg 6 to 15 years: 1 g Over 15 years: 1.2 g
Trigeminal neuralgia	Oral: initially 100 mg 1-2 times daily, increased gradually according to response; usual dose 200 mg 3-4 times daily, up to 1.6 g daily in some patients
Bipolar disorder	Oral: initially 400 mg daily in divided doses increasleed until symptoms controlled; usual range 400-600 mg daily; max. 1.6 g daily
Treatment of alcohol withdrawal	Oral: initially 800 mg daily in divided doses, reduced gradually over 5 days to 200 mg daily; usual treatment duration 7-10 days.
Diabetic neuropathy	Oral: initially 100 mg 1-2 times daily, increased gradually according to response; usual dose 200 mg 3-4 times daily, up to 1.6 g daily in some patients

Note Plasma concentration for optimum response 4-12 mg/litre (20-50 micromol/litre)

Side Effects

Common side effects include:

• Drowsiness, dizziness and headaches
• Gastrointestinal disturbances, such as nausea and vomiting
• The loss of full control of bodily movements (motor coordination impairment)
• Increased risks of hyponatremia and SIADH
• Blood disorders (such as decreased white blood cell or platelet counts)

Serious side effects may include:

• Skin rashes, exfoliative dermatitis, epidermal necrolysis, Stevens-Johnson syndrome, and SLE
• Decreased bone marrow function
• Suicidal thoughts
• Abnormal heart rhythms
• Blurry or double vision, nystagmus
• Male infertility
• Osteoporosis
• Gynecomastia
• Galactorrhea