carbamazepine


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carbamazepine

 [kahr″bah-maz´ĕ-pēn]
an anticonvulsant and analgesic used in the treatment of pain associated with trigeminal neuralgia and for control of complex partial seizures or generalized tonic-clonic seizures in patients who do not respond to phenytoin, phenobarbital, or primidone.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

carbamazepine

Apo-Carbamazepine (CA), Arbil (UK), Bio-Carbamazepine (CA), Carbagen (UK), Carbamaz (CA), Carbatrol, Dom-Carbamazepine (CA), Epimaz (UK), Epitol, Equetro, Gen-Carbamazepine (CA) Mazepine (CA), Novo-Carbamazepine (CA), Nu-Carbamazepine (CA), PHL-Carbamazepine (CA), PMS-Carbamazepine (CA), Sandoz Carbamazepine (CA), Tegretol, Tegretol-XR

Pharmacologic class: Iminostilbene derivative

Therapeutic class: Anticonvulsant

Pregnancy risk category D

FDA Box Warning

• Prescriber should be thoroughly familiar with prescribing information, particularly regarding use with other drugs (especially those that increase toxicity potential).

• Drug has been linked to aplastic anemia and agranulocytosis.

• Transient or persistent decreases in platelet or white blood cell (WBC) counts have occurred, but data aren't available to accurately estimate incidence or outcome. Rarely, leukopenia cases progressed to aplastic anemia or agranulocytosis.

• Obtain complete pretreatment hematologic tests as baseline. If WBC or platelet count drops during therapy, monitor closely. Consider withdrawing drug if evidence of significant bone marrow depression develops.

Action

Unclear. Chemically related to tricyclic antidepressants (TCAs). Anticonvulsant action may result from reduction in polysynaptic responses and blocking of post-tetanic potentiation.

Availability

Capsules (extended-release): 100 mg, 200 mg, 300 mg

Oral suspension: 100 mg/5 ml

Tablets: 200 mg

Tablets (chewable): 100 mg

Tablets (extended-release): 100 mg,

200 mg, 400 mg

Indications and dosages

Prophylaxis of generalized tonic-clonic, mixed, and complex-partial seizures

Adults and children ages 12 and older: Initially, 200 mg P.O. b.i.d. (tablets) or 100 mg q.i.d. (oral suspension). Increase by up to 200 mg/day q 7 days until therapeutic blood levels are reached. Usual maintenance dosage is 600 to 1,200 mg/day in divided doses q 6 to 8 hours. In children ages 12 to 15, don't exceed 1 g/day. Give extended-release forms b.i.d.

Children ages 6 to 12: Initially, 100 mg P.O. b.i.d. (tablets) or 50 mg q.i.d. (oral suspension). Increase by up to 100 mg weekly until therapeutic levels are reached. Usual maintenance dosage is 400 to 800 mg/day. Don't exceed 1 g/day. Give extended-release forms b.i.d.

Children younger than age 6: Initially, 10 to 20 mg/kg/day P.O. in two or three divided doses. May increase by up to 100 mg/day at weekly intervals. Usual maintenance dosage is 250 to 350 mg/day. Don't exceed 400 mg/day.

Trigeminal neuralgia

Adults: Initially, 100 mg b.i.d. (tablets) or 50 mg q.i.d. (oral suspension). Increase by up to 200 mg/day until pain relief occurs; then give maintenance dosage of 200 to 1,200 mg/day in divided doses. Usual maintenance range is 400 to 800 mg/day.

Off-label uses

• Alcohol, cocaine, or benzodiazepine withdrawal

• Atypical psychoses

• Central diabetes insipidus

• Mood disorders

• Neurogenic pain

Contraindications

• Hypersensitivity to drug or TCAs

• MAO inhibitor use within past 14 days

• Bone marrow depression

• Pregnancy or breastfeeding

Precautions

Use cautiously in:

• cardiac disease, hepatic disease, increased intraocular pressure, mixed seizure disorders, glaucoma

• elderly males with prostatic hypertrophy

• psychiatric patients.

Administration

• Don't give within 14 days of MAO inhibitor.

• Give tablets with meals; may give extended-release capsules without regard to meals.

• Don't give with grapefruit juice.

• If desired, contents of extended-release capsules may be sprinkled over food; however, capsule and contents shouldn't be crushed or chewed.

Adverse reactions

CNS: ataxia, drowsiness, fatigue, psychosis, syncope, vertigo, headache, worsening of seizures

CV: hypertension, hypotension, arrhythmias, atrioventricular block, aggravation of coronary artery disease, heart failure

EENT: blurred vision, diplopia, nystagmus, corneal opacities, conjunctivitis, pharyngeal dryness

GI: nausea, vomiting, diarrhea, abdominal pain, stomatitis, glossitis, dry mouth, anorexia

GU: urinary hesitancy, retention, or frequency; albuminuria; glycosuria; erectile dysfunction

Hematologic: eosinophilia, lymph-adenopathy, agranulocytosis, aplastic anemia, thrombocytopenia, leukopenia

Hepatic: hepatitis

Metabolic: syndrome of inappropriate antidiuretic hormone secretion

Respiratory: pneumonitis

Skin: photosensitivity, rash, urticaria, diaphoresis, erythema multiforme, Stevens-Johnson syndrome

Other: weight gain, chills, fever

Interactions

Drug-drug. Acetaminophen: increased risk of acetaminophen-induced hepatotoxicity, decreased acetaminophen efficacy

Anticoagulants, bupropion: increased metabolism of these drugs, causing decreased efficacy

Barbiturates: decreased barbiturate blood level, increased carbamazepine blood level

Charcoal: decreased carbamazepine absorption

Cimetidine, danazol, diltiazem: increased carbamazepine blood level

Cyclosporine, felbamate, felodipine, haloperidol: decreased blood levels of these drugs

Doxycycline: shortened doxycycline half-life and reduced antimicrobial effect

Hormonal contraceptives: decreased contraceptive efficacy, possibly leading to pregnancy

Hydantoins: increased or decreased hydantoin blood level, decreased carbamazepine blood level

Isoniazid: increased risk of carbamazepine toxicity and isoniazid hepatotoxicity

Lithium: increased risk of CNS toxicity Macrolide antibiotics (such as clarithromycin and erythromycin), propoxy-phene, selective serotonin reuptake inhibitors (such as fluoxetine and flu-voxamine), verapamil: increased carbamazepine blood level, greater risk of toxicity

MAO inhibitors: high fever, hypertension, seizures, and possibly death

Nondepolarizing neuromuscular blockers: shortened carbamazepine duration of action

TCAs: increased carbamazepine blood level and greater risk of toxicity, decreased TCA blood level

Valproic acid: decreased valproic acid blood level with possible loss of seizure control, variable changes in carbamazepine blood level

Drug-diagnostic tests. Blood urea nitrogen, eosinophils, liver function tests: increased values

Granulocytes, hemoglobin, platelets, thyroid function tests, white blood cells: decreased values

Drug-food. Grapefruit juice: increased drug blood level and effects

Drug-herbs. Plantain (psyllium seed): inhibited GI absorption of drug

Patient monitoring

Monitor patient closely. Institute seizure precautions if drug must be withdrawn suddenly.

• Assess for history of psychosis; drug may activate symptoms.

• Monitor baseline hematologic, kidney, and liver function test results.

• During dosage adjustments, monitor vital signs and fluid intake and output. Stay alert for fluid retention, renal failure, and cardiovascular complications.

• With high doses, monitor CBC weekly for first 3 months and then monthly to detect bone marrow depression.

Patient teaching

• Tell patient that he may sprinkle contents of extended-release capsules over food, but that he shouldn't crush or chew capsule or contents.

• Advise patient that coating on extended-release capsules may be visible in stools because it isn't absorbed.

• Tell patient to take drug with meals to minimize GI upset.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, alertness, and vision.

• Advise patient to avoid excessive sun exposure and to wear protective clothing and sunscreen.

• Inform female patient that drug may interfere with hormonal contraception. Advise her to use alternative birth-control method.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, herbs, and behaviors mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved

carbamazepine

(kär′bə-măz′ə-pēn′)
n.
An anticonvulsant drug, C15H12N2O, used to treat certain forms of epilepsy and to relieve pain associated with trigeminal neuralgia.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

carbamazepine

An anticonvulsant used to manage partial seizures and generalised tonic-clonic seizures in children, bipolar disorder and trigeminal neuralgia; in contrast to valproate, carbamazepine is associated with better seizure control, fewer seizures and longer time to first seizure. 

Adverse effects
Dizziness, drowsiness, unsteadiness, nausea, vomiting, myelosuppression (up to 8-fold increase) in aplastic anaemia and agranulocytosis, rash, hair loss.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

carbamazepine

Carbatrol®, Tegretol®, divalproex Neurology An anticovulsant used as a monotherapy for treating partial seizures–eg, generalized tonic-clonic seizures in children; in contrast to valproate which is as effective as carbamazepine in treating generalized tonic-clonic seizures, carbamazepine is associated with better seizure control and seizure-rating score, ↓ seizures, and time to first seizure; it may be used for manic episodes Adverse effects Rash, hair loss, tremor, myelosuppression; carbamazepine induces enzymes that metabolize warfarin, clonazepine, phenytoin T1/2 15 hrs Therapeutic range 4–10 mg/L Toxic range ≥ 15 mg/L. See Convulsions, Seizures. Cf Valproate.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

carbamazepine

A drug used in the control of EPILEPSY and especially to relieve or prevent the pain of TRIGEMINAL NEURALGIA. The drug is on the WHO official list. A brand name is Tegretol.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
A case of induced lupus due to carbamazepine. J Rheumatol 1987;14:599-600.
SEM of Carbamazepine treated liver sample showed marked changes in the surface of hepatocytes.
Although the suspicious drug in our patient was carbamazepine, valproic acid was also additionally discontinued.
Caffeine suffered less influence of the matrix (14% attenuation), followed by atrazine (18%) and carbamazepine (19%).
Most cases received carbamazepine to treat epilepsy (29 cases), except for 9 patients who received carbamazepine to treat trigeminal neuralgia (5 cases), neuropathic pain (2 cases), bipolar disorder (1 case), and paroxysmal kinesigenic and nonkinesigenic dyskinesia (1 case).
Each group comprised of 100 subjects labeled as Group-A (control group had healthy individuals), Group-B (newly diagnosed epileptic patients without antiepileptic therapy), Group-C (epileptic patients on Carbamazepine therapy, which was further subdivided into C-I having epileptic patients on Carbamazepine therapy less than 1 year n = 33, C-II had epileptic patients on Carbamazepine therapy 1-2 years n = 33 and C-III comprised of epileptic patients on Carbamazepine therapy more than 2 years n = 34).
Carbamazepine that was initially used as an antiepileptic is now also used with increased frequency for different indications including chronic pain, trigeminal neuralgia and herpetic neuralgias.
The Phase III study also revealed that the tolerability of eslicarbazepine acetate was similar to that of the twice-daily controlled-release carbamazepine, with the side effects of eslicarbazepine acetate being mostly mild and consistent with the known safety profile that was observed in previous studies.
Patients on carbamazepine as initial AED are 2.1 times more likely to have better retention rate as compared to other AEDs at the end of 1-year follow-up (OR: 2.1, 95% CI: 1.03-4.24).
Given the lack of mucosal involvement and typical targetoid lesions on exam, she was diagnosed with an atypical erythema multiforme, likely secondary to carbamazepine. She was treated with methylprednisolone 60 mg intravenously every 6 hours for 2 days, then changed to oral prednisone 60 mg daily.
We wish to highlight the pretreatment screening, monitoring regime, and prevention for recurrent SJS for all dental practitioners involved in the prescription of carbamazepine.
Conclusion: Carbamazepine intoxication ranked first among the intoxications due to anticonvulsant exposures.