Share on Facebook
Share on Twitter
Share on LinkedIn
Share by Email
Print
Tegretol-xr Generic Name & Formulations
Legal Class
Rx
General Description
Carbamazepine 100mg, 200mg, 400mg; ext-rel tabs.
Pharmacological Class
Dibenzazepine.
See Also
How Supplied
Tabs—60, 100; XR tabs—100; Susp—450mL
Manufacturer
Mechanism of Action
Tegretol appears to act by reducing polysynaptic responses and blocking the post-tetanic potentiation. It is chemically unrelated to other anticonvulsants or other drugs used to control the pain of trigeminal neuralgia. The mechanism of action remains unknown.
Tegretol-xr Indications
Indications
Trigeminal or glossopharyngeal neuralgia.
Tegretol-xr Dosage and Administration
Adult
Take with food. XR tabs: swallow whole. Give in 2 divided doses. Initially 100mg twice daily; increase if needed by up to 200mg/day. Max 1.2g/day. Maintenance: usually 400–800mg daily. Taper dosage or discontinue if possible at 3 month intervals.
Children
Not established.
Tegretol-xr Contraindications
Contraindications
History of bone marrow depression. Sensitivity to tricyclic antidepressants. During or within 14 days of MAOIs. Concomitant nefazodone.
Tegretol-xr Boxed Warnings
Boxed Warning
Serious dermatologic reactions and HLA-B*1502 allele. Aplastic anemia and agranulocytosis.
Tegretol-xr Warnings/Precautions
Warnings/Precautions
Evaluate for presence of HLA-B*1502 allele (esp. in Asians), if present carbamazepine should not be used; increased risk of severe dermatologic reactions. Patients known to be HLA-A*3101 positive; increased risk of hypersensitivity reactions. Discontinue at the first sign of rash, or if anaphylaxis or angioedema occurs (do not rechallenge). Prior adverse hematologic reaction to any drug. Do baseline CBCs then periodically; discontinue if significant bone marrow depression occurs. History of cardiac conduction disturbance. 2nd or 3rd degree AV heart block. Cardiac, hepatic, or renal damage. Avoid in hepatic porphyria. Monitor ophthalmic, hepatic, and renal function. Increased intraocular pressure; monitor. Mixed seizure disorder with atypical absence seizures (may increase generalized convulsions). Monitor for new or worsening depression, suicidal thoughts, unusual changes in behavior. Activation of latent psychosis. Use minimum effective dose; adjust gradually. Avoid abrupt cessation. Convert tabs to susp with same quantity of mg/day in smaller, more frequent doses; convert tabs to XR on daily mg/mg basis. Suspension: avoid in fructose intolerance. Elderly. Labor & delivery. Pregnancy; can cause fetal harm. Nursing mothers; not recommended.
Tegretol-xr Pharmacokinetics
Absorption
Suspension, tablets, and XR tablets deliver equivalent amounts of drug to the systemic circulation. The suspension was absorbed somewhat faster, and the XR tablet slightly slower, vs the conventional tablet. Peak plasma levels occurred at ~1.5 hours (suspension), 4–5 hours (tablets), and 3–12 hours (XR tablets).
Distribution
Plasma protein bound: 76%.
Elimination
Renal (72%), fecal (28%). Half-life: 25–65 hours.
Tegretol-xr Interactions
Interactions
See Contraindications. Cross-sensitivity possible with oxcarbazepine. Avoid concomitant temsirolimus, lapatinib; if necessary, adjust dose. Concomitant rivaroxaban, apixaban, dabigatran, edoxaban; avoid. Potentiated by CYP3A4 inhibitors (eg, aprepitant, cimetidine, ciprofloxacin, danazol, diltiazem, macrolides, erythromycin, troleandomycin, clarithromycin, fluoxetine, fluvoxamine, trazodone, olanzapine, loratadine, terfenadine, omeprazole, oxybutynin, dantrolene, isoniazid, niacinamide, nicotinamide, ibuprofen, propoxyphene, azole antifungals, acetazolamide, verapamil, ticlopidine, grapefruit juice, protease inhibitors), loxapine, quetiapine, valproate. Antagonized by CYP3A4 inducers (eg, cisplatin, doxorubicin, felbamate, fosphenytoin, rifampin, phenobarbital, phenytoin, primidone, methsuximide, theophylline, aminophylline). May potentiate cyclophosphamide. May antagonize phenytoin, warfarin, doxycycline, theophylline, haloperidol, acetaminophen, alprazolam, clozapine, oral contraceptives, anticonvulsants, aripiprazole, others metabolized by CYP3A4. May increase lithium toxicity, isoniazid-induced hepatotoxicity. Monitor tacrolimus, valproate levels. Symptomatic hyponatremia possible with diuretics. Caution with alcohol. Monitor for rapid recovery from neuromuscular blockade. May alter thyroid function with other anticonvulsants. Do not give susp formulation simultaneously with other liquid drugs or diluents. May interfere with some pregnancy tests, thyroid function tests. See full labeling.
Tegretol-xr Adverse Reactions
Adverse Reactions
Drowsiness, dizziness, unsteadiness, nausea, vomiting; hyponatremia, bone marrow depression, DRESS/multiorgan hypersensitivity, cardiac and hepatic effects, suicidal ideation; rare: serious skin reactions (eg, Stevens-Johnson syndrome, toxic epidermal necrolysis), aplastic anemia, agranulocytosis, anaphylaxis.
Tegretol-xr Clinical Trials
See Literature
Tegretol-xr Note
Not Applicable
Tegretol-xr Patient Counseling
See Literature
Tegretol-xr Generic Name & Formulations
Legal Class
Rx
General Description
Carbamazepine 100mg, 200mg, 400mg; ext-rel tabs.
Pharmacological Class
Dibenzazepine.
See Also
How Supplied
Tabs—60, 100; XR tabs—100; Susp—450mL
Manufacturer
Mechanism of Action
Tegretol appears to act by reducing polysynaptic responses and blocking the post-tetanic potentiation. It is chemically unrelated to other anticonvulsants or other drugs used to control the pain of trigeminal neuralgia. The mechanism of action remains unknown.
Tegretol-xr Indications
Indications
Generalized tonic-clonic, partial or mixed seizures.
Tegretol-xr Dosage and Administration
Adult
Swallow whole. Take with food. Give in 2 divided doses. Initially 200mg twice daily; increase weekly if needed by up to 200mg/day. 12–15yrs: max 1g daily; >15yrs: usual max 1.2g daily (rarely, max 1.6g daily). Usual maintenance: 800mg–1.2g/day.
Children
Swallow whole. Take with food. Give in 2 divided doses. <6yrs: use other forms. 6–12yrs: initially 100mg twice daily; increase weekly if needed by up to 100mg/day; max 1g daily. Usual maintenance: 400mg–800mg/day.
Tegretol-xr Contraindications
Contraindications
History of bone marrow depression. Sensitivity to tricyclic antidepressants. During or within 14 days of MAOIs. Concomitant nefazodone.
Tegretol-xr Boxed Warnings
Boxed Warning
Serious dermatologic reactions and HLA-B*1502 allele. Aplastic anemia and agranulocytosis.
Tegretol-xr Warnings/Precautions
Warnings/Precautions
Evaluate for presence of HLA-B*1502 allele (esp. in Asians), if present carbamazepine should not be used; increased risk of severe dermatologic reactions. Patients known to be HLA-A*3101 positive; increased risk of hypersensitivity reactions. Discontinue at the first sign of rash, or if anaphylaxis or angioedema occurs (do not rechallenge). Prior adverse hematologic reaction to any drug. Do baseline CBCs then periodically; discontinue if significant bone marrow depression occurs. History of cardiac conduction disturbance. 2nd or 3rd degree AV heart block. Cardiac, hepatic, or renal damage. Avoid in hepatic porphyria. Monitor ophthalmic, hepatic, and renal function. Increased intraocular pressure; monitor. Mixed seizure disorder with atypical absence seizures (may increase generalized convulsions). Monitor for new or worsening depression, suicidal thoughts, unusual changes in behavior. Activation of latent psychosis. Use minimum effective dose; adjust gradually. Avoid abrupt cessation. Convert tabs to susp with same quantity of mg/day in smaller, more frequent doses; convert tabs to XR on daily mg/mg basis. Suspension: avoid in fructose intolerance. Elderly. Labor & delivery. Pregnancy; can cause fetal harm. Nursing mothers; not recommended.
Tegretol-xr Pharmacokinetics
Absorption
Suspension, tablets, and XR tablets deliver equivalent amounts of drug to the systemic circulation. The suspension was absorbed somewhat faster, and the XR tablet slightly slower, vs the conventional tablet. Peak plasma levels occurred at ~1.5 hours (suspension), 4–5 hours (tablets), and 3–12 hours (XR tablets).
Distribution
Plasma protein bound: 76%.
Elimination
Renal (72%), fecal (28%). Half-life: 25–65 hours.
Tegretol-xr Interactions
Interactions
See Contraindications. Cross-sensitivity possible with oxcarbazepine. Avoid concomitant temsirolimus, lapatinib; if necessary, adjust dose. Concomitant rivaroxaban, apixaban, dabigatran, edoxaban; avoid. Potentiated by CYP3A4 inhibitors (eg, aprepitant, cimetidine, ciprofloxacin, danazol, diltiazem, macrolides, erythromycin, troleandomycin, clarithromycin, fluoxetine, fluvoxamine, trazodone, olanzapine, loratadine, terfenadine, omeprazole, oxybutynin, dantrolene, isoniazid, niacinamide, nicotinamide, ibuprofen, propoxyphene, azole antifungals, acetazolamide, verapamil, ticlopidine, grapefruit juice, protease inhibitors), loxapine, quetiapine, valproate. Antagonized by CYP3A4 inducers (eg, cisplatin, doxorubicin, felbamate, fosphenytoin, rifampin, phenobarbital, phenytoin, primidone, methsuximide, theophylline, aminophylline). May potentiate cyclophosphamide. May antagonize phenytoin, warfarin, doxycycline, theophylline, haloperidol, acetaminophen, alprazolam, clozapine, oral contraceptives, anticonvulsants, aripiprazole, others metabolized by CYP3A4. May increase lithium toxicity, isoniazid-induced hepatotoxicity. Monitor tacrolimus, valproate levels. Symptomatic hyponatremia possible with diuretics. Caution with alcohol. Monitor for rapid recovery from neuromuscular blockade. May alter thyroid function with other anticonvulsants. Do not give susp formulation simultaneously with other liquid drugs or diluents. May interfere with some pregnancy tests, thyroid function tests. See full labeling.
Tegretol-xr Adverse Reactions
Adverse Reactions
Drowsiness, dizziness, unsteadiness, nausea, vomiting; hyponatremia, bone marrow depression, DRESS/multiorgan hypersensitivity, cardiac and hepatic effects, suicidal ideation; rare: serious skin reactions (eg, Stevens-Johnson syndrome, toxic epidermal necrolysis), aplastic anemia, agranulocytosis, anaphylaxis.
Tegretol-xr Clinical Trials
See Literature
Tegretol-xr Note
Not Applicable
Tegretol-xr Patient Counseling
See Literature
Images
