Other Warnings/Precautions

✽ Patients should be monitored carefully for signs of unusual bleeding or bruising, mouth sores, infections, fever, or sore throat, as the risk of aplastic anemia and agranulocytosis with carbamazepine use is 5–8 times greater than in the general population (risk in the untreated general population is 6 patients per 1 million per year for agranulocytosis and 2 patients per 1 million per year for aplastic anemia)

• Because carbamazepine has a tricyclic chemical structure, use with caution with MAO inhibitors, including 14 days after MAOIs are stopped (for the expert)

• May exacerbate angle-closure glaucoma

• Because carbamazepine can lower plasma levels of hormonal contraceptives, it may also reduce their effectiveness

• May need to restrict fluid intake because of risk of developing syndrome of inappropriate antidiuretic hormone secretion, hyponatremia and its complications

• Use with caution in patients with mixed seizure disorders that include atypical absence seizures because carbamazepine has been associated with increased frequency of generalized convulsions in such patients

• Individuals with the HLA-B*1502 allele are at increased risk of developing Stevens-Johnson syndrome and toxic epidermal necrolysis

• Warn patients and their caregivers about the possibility of activation of suicidal ideation and advise them to report such side effects immediately

Do Not Use

• If patient has history of bone marrow suppression

• If patient tests positive for the HLA-B*1502 allele

• If there is a proven allergy to any tricyclic compound

• If there is a proven allergy to carbamazepine

CARBAMAZEPINE: SPECIAL POPULATIONS

Renal Impairment

• Carbamazepine is renally secreted, so the dose may need to be lowered

Hepatic Impairment

• Drug should be used with caution

• Rare cases of hepatic failure have occurred

Cardiac Impairment

• Drug should be used with caution

Elderly

• Some patients may tolerate lower doses better

• Elderly patients may be more susceptible to adverse effects

Children and Adolescents

• Approved use for epilepsy; therapeutic range of total carbamazepine in plasma is considered the same for children and adults

• Ages 6–12: initial dose 100 mg twice daily (tablets) or 0.5 teaspoon (50 mg) 4 times a day (suspension); each week increase by up to 100 mg/day in divided doses (2 doses for extended release formulation, 3–4 doses for all other formulations); maximum dose generally 1,000 mg/day; maintenance dose generally 400–800 mg/day

• Ages 5 and younger: initial 10–20 mg/kg per day in divided doses (2–3 doses for tablet formulations, 4 doses for suspension); increase weekly as needed; maximum dose generally 35 mg/kg/day

Pregnancy

• Risk Category D [positive evidence of risk to human fetus; potential benefits may still justify its use during pregnancy]

✽ Use during first trimester may raise risk of neural tube defects (e.g., spina bifida) or other congenital anomalies

• Use in women of childbearing potential requires weighing potential benefits to the mother against the risks to the fetus

✽ If drug is continued, perform tests to detect birth defects

✽ If drug is continued, start on folate 1 mg/day early in pregnancy to reduce risk of neural tube defects

• Antiepileptic Drug Pregnancy Registry: (888) 233–2334

• Use of anticonvulsants in combination may cause a higher prevalence of teratogenic effects than anticonvulsant monotherapy

• Taper drug if discontinuing

• Seizures, even mild seizures, may cause harm to the embryo/fetus

✽ For bipolar patients, carbamazepine should generally be discontinued before anticipated pregnancies

• Recurrent bipolar illness during pregnancy can be quite disruptive

• For bipolar patients, given the risk of relapse in the postpartum period, some form of mood stabilizer treatment may need to be restarted immediately after delivery if patient is unmedicated during pregnancy

✽ Atypical antipsychotics may be preferable to lithium or anticonvulsants such as carbamazepine if treatment of bipolar disorder is required during pregnancy

• Bipolar symptoms may recur or worsen during pregnancy and some form of treatment may be necessary