AnticonvulsantUS FDA Database Verified

carBAMazepine (Rx)

Generic: CarBAMazepine

Brand: Carbatrol, Equetro, Mazepine, NovoCarbamaz, TEGretol, TEGretol- XRF

(kar- ba- maz'e- peen)

Pregnancy Category: D

Pharmacological Action

Exact mechanism unknown; appears to decrease polysynaptic responses and block posttetanic potentiation

Therapeutic outcome: Absence of seizures; decreased trigeminal neuralgia pain

Uses

Tonic- clonic, complex- partial, mixed seizures; trigeminal neuralgia; bipolar disorder

Contraindications

Pregnancy D, hypersensitivity to carBAMazepine or tricyclics

BLACK BOX WARNING: Bone marrow suppression

Precautions: Glaucoma, renal/hepatic/cardiac disease, psychosis, breastfeeding, child < 6 yr, alcoholism, hepatic porphyria, AV or bundle branch block

BLACK BOX WARNING: Hematologic disease, agranulocytosis, leukopenia, neutropenia, thrombocytopenia, Asian patients

Dosage & Routes

Seizures Adult and child >12 yr: PO 200 mg bid; may be increased by 200 mg/day in weekly intervals, give in divided doses q6- 8 hr; maintenance 800- 1200 mg/day; max 1600 mg/day (adult); max child 12- 15 yr 1000 mg/day; max child >15 yr 1200 mg/day; adjustment is needed to minimum dose to control seizures; EXT REL give bid; RECT administration of oral SUSP 200 mg/10 ml or 6 mg/kg as a single dose Child 6- 12 yr: PO tabs 100 mg bid or SUSP 50 mg qid; may increase by < 100 mg qwk, max 1000 mg/day, usual dose 15- 30 mg/kg/day; EXT REL tabs daily- bid Child < 6 yr: PO 10- 20 mg/kg/day in 2- 3 divided doses or 4 divided doses (susp), may increase qwk Trigeminal neuralgia

Adult: PO 100 mg/bid; may increase 100 mg q12 hr until pain subsides; max 1200 mg/day; maintenance is 200- 400 mg bid Bipolar disorder

Adult: PO (Equetro only) (regular release) 200 mg bid, may adjust dose 3- 4 days to achieve carBAMazepine level to 8- 12 mcg/ml micro response; max 1600 mg/day Agitation due to dementia (unlabeled)

Adult: PO 100 mg bid, may increase to 250- 300 mg/day Hiccups (unlabeled)

Adult: PO 200 mg tid

Available forms: Chewable tabs 100, 200 mg; oral susp 100 mg/5 ml; ext rel tabs 100, 200, 400 mg; ext rel caps (Carbatrol) 200, 300 mg

Implementation - Do not break, crush, or chew ext rel tabs and caps: ext rel caps may be opened and beads mixed with food; chewable tabs should be chewed, not swallowed whole - Give with food for GI symptoms - Shake oral susp before use -

Suspension: Turn off N/G, internal feeding 15 min before and hold for 15 min after; mix an equal amount of water, D,W, 0.9% NaCl when giving by NG tube, flush tube with 15- 30 ml of above sol - Store at room temperature

Adverse Effects

CNS: Drowsiness, dizziness, confusion, fatigue, paralysis, headache, hallucinations, worsening of seizures, unsteadiness, speech disturbances, suicidal ideation, neuroleptic malignant syndrome (when used with psychotropics)

CV: Hypertension, CHF, hypotension, aggravation of CAD, dysrhythmias, AV block

EENT: Tinnitus, dry mouth, blurred vision, diplopia, nystagmus, conjunctivitis

ENDO: Syndrome of inappropriate antidiuretic hormone (SIADH) (geriatric)

GI: Nausea, constipation, diarrhea, anorexia, vomiting, abdominal pain, stomatitis, glossitis, increased liver enzymes, hepatitis, hepatic porphyria, hypercholesterolemia, pancreatitis

GU: Frequency, retention, albuminuria, glycosuria, impotence, increased BUN, renal failure

HEMA: Thrombocytopenia, leukopenia, agranulocytosis, leukocytosis, aplastic anemia, eosinophilia, increased pro- time, lymphadenopathy

INTEG: Rasb, Stevens- Johnson syndrome, urticaria, photosensitivity, toxic epidermal necrolysis, DRESS, alopecia

MS: Osteoporosis

RESP: Pulmonary hypersensitivity (fever, dyspnea, pneumonitis)

Pharmacokinetics

Absorption: Slow; completely absorbed

Distribution: Widely distributed; protein binding 76%

Metabolism: Extensively, liver, metabolized by CYP3 A4

Excretion: Urine, feces, breast milk

Half-life: 18-65 hr, then 8-29 hr after first month

Pharmacodynamics

Onset Slow, Peak 4-5 hr (PO), 1.5 hr (ssup), Duration Unknown

Interactions

Individual drugs Benzodiazepines, darunavir, delavirdine, doxycycline, felbamate, haloperidol, nefazodone, Oxcarbazepine, PHENobarbitol, phenytoin, primidone: decreased effect of these products Cimetidine, clarithromycin, danzol, diltiazem, erythromycin, FLUoxetine, fluvoxamine, isoniazid, propoxyphene, valproic acid, verapamil, voriconazole: increased carbAMazepine levels Clofalatin, darunavir, delavirdine, DOXorubicin, felbamate, nefazodone, Oxcarbazepine, PHENobarbitol, phenytoin, primidone, rifampin, theophylline: decreased carbAMazepine levels Contraceptives (oral): decreased effect of oral contraceptives Desmopressin, lithium, hypressin, vasopressin: increased effects of each specific product

Doxycycline: decreased effect of doxycycline

Lithium: increased CNS toxicity

Phenytoin: increased and decreased plasma levels; decreased carbAMazepine plasma levels Thyroid hormones: decreased effect of thyroid hormones

Warfarin: decreased effect of warfarin

Drug classifications CYP3 A4 inducers: decreased carbAMazepine levels CYP3 A4 inhibitors: increased carbAMazepine levels Do not use with: NNRTIs (non- nucleoside reverse- transcriptase inhibitors), nefazodone

Drug/herb

Echinacea: decreased carbAMazepine metabolism, increased levels St. John's wort: decreased anticonvulsant action

Drug/food Grapefruit juice: increased peak concentration of carbAMazepine

Drug/lab test

Decreased: serum calcium, sodium

Increased: cholesterol

Nursing Considerations

Assessment

BLACK BOX WARNING: Serious skin reactions: Asian patient, obtain genetic test prior to administration - Assess for seizures: character, location, duration, intensity, frequency, presence of aura - Assess for trigeminal neuralgia: facial pain including location, duration, intensity, character, activity that stimulates pain - Monitor liver function tests (AST, ALT) and urine function tests, BUN, urine protein periodically during treatments; serum calcium may be decreased and lead to osteoporosis; cholesterol periodically - Bone marrow depression: Assess blood studies: RBC, Hct, Hgb, reticulocyte counts qwk for 4 wk then q3- 6 mo if on long- term therapy; if myelosuppression occurs, product should be discontinued - Serious skin, multi- organ hypersensitivity (Stevens- Johnson syndrome, toxic epidermal necrolysis, DRESS): May be increased in HLA- A 3101 gene and may be fatal - Check blood levels during treatment or when changing dose; therapeutic level 4- 12 mcg/ml - Assess for blood dyscrasias: fever, sore throat, bruising, rash, jaundice, epistaxis (longterm treatment only) - Assess mental status: mood, sensorium, affect, behavioral changes, suicidal thoughts/behaviors -

Toxicity: Assess for bone marrow depression, nausea, vomiting, ataxia, diplopia, CV collapse, Stevens-Johnson syndrome

Patient/family education - Teach patient to carry/wear emergency ID stating patient's name, products taken, condition, prescriber's name, phone number - Caution patient to avoid driving, other activities that require alertness until stabilized on medication - Teach patient not to discontinue medication quickly after long-term use - Teach patient to use a nonhormonal type of contraception to prevent harm to the fetus - Advise patient to use sunscreen to prevent burns - Teach patient to take exactly as prescribed; do not double or omit doses - Teach patient to report immediately chills, rash, light-colored stools, dark urine, yellowing of skin/eyes, abdominal pain, sore throat, mouth ulcers, bruising, blurred vision, dizziness, skin rash, fever - Teach patient to notify if pregnancy is planned or suspected, pregnancy (D), avoid breastfeeding

Evaluation

Positive therapeutic outcome: Decreased seizure activity

Reference

Mosby's Drug Guide; Davis Drug Guide

Need clinical tools for this drug?

Save notes, bookmark this drug, and run formula method (desire over have) dosage calculations all inside the KosPharm Dashboard.

One-time payment. No subscription. No recurring charges.