Carbamazepine Side Effects

Some side effects of carbamazepine may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

For the Consumer

Applies to carbamazepine: oral capsule extended release, oral suspension, oral tablet, oral tablet chewable, oral tablet extended release

Get emergency medical help if you have any of these signs of an allergic reaction while taking carbamazepine: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Report any new or worsening symptoms to your doctor, such as: sudden mood or behavior changes, depression, anxiety, insomnia, or if you feel agitated, hostile, restless, irritable, or have thoughts about suicide or hurting yourself.

Call your doctor at once if you have:

• fever, tired feeling, weakness, confusion, pale skin, feeling light-headed or short of breath;

• easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;

• slow, fast, or pounding heartbeats;

• confusion, vision problems, hallucinations;

• nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

• little or no urinating;

• swelling, rapid weight gain;

• problems with your fingernails or toenails; or

• severe skin reaction -- fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common side effects may include:

• dizziness, drowsiness,

• nausea, vomiting, feeling unsteady;

• dry mouth, swollen tongue; or

• loss of balance or coordination.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For Healthcare Professionals

Applies to carbamazepine: compounding powder, oral capsule extended release, oral suspension, oral tablet, oral tablet chewable, oral tablet extended release

Gastrointestinal

A single case of chemical pancreatitis has been reported in association with carbamazepine intoxication.

Very common (10% or more): Nausea (29%), vomiting (18%), constipation (10%)
Postmarketing reports: Gastric distress, abdominal pain, diarrhea, anorexia, glossitis, stomatitis

Endocrine

Frequency not reported: Hyponatremia, pancreatitis

Carbamazepine increases the rate of T4 and T3 metabolism and may lead to hypothyroidism in patients with hypothyroidism who are being treated with T4. Carbamazepine may also cause a 20% to 40% decrease in serum total and free T4 concentrations and a smaller decrease in serum total and free T3 concentrations in patients who have no thyroid disease.

Chronic administration of carbamazepine may increase total cholesterol and HDL cholesterol levels. Carbamazepine may also transiently increase serum triglyceride and LDL cholesterol levels. One study has suggested that demeclocycline may be useful in prophylaxis of carbamazepine-induced hyponatremia.

Hematologic

Thrombocytopenia is the most common hematologic effect of carbamazepine and may be either mild and transient or severe. Significant decreases in white blood cell counts may occur although the values may still be within the normal range. Often counts will return to baseline during continued therapy, and therefore, discontinuation of carbamazepine may not be necessary. Dose reductions may also result in normalization of white blood cell counts. Aplastic anemia has been reported (although many of the reported cases had confounding exposures to other medications). The manufacturer reports an incidence of 2 per 1,000,000 patients for aplastic anemia and 6 per 1,000,000 patients for agranulocytosis. Cases of reticulocytosis have been reported rarely in association with carbamazepine therapy as well. In addition, cases of hemolytic anemia and erythroid arrest have been reported.

Both humoral and nonimmune mechanisms have been implicated in the etiology of carbamazepine-induced bone marrow suppression.

Frequency not reported: Aplastic anemia, agranulocytosis, pancytopenia, bone marrow depression, thrombocytopenia, leukopenia, leukocytosis, eosinophilia, anemia, acute intermittent porphyria, variegate porphyria, porphyria cutanea tarda, thrombophlebitis, thromboembolism (e.g., pulmonary embolism), adenopathy or lymphadenopathy

Cardiovascular

Frequency not reported: Various forms of heart block, hypotension, electrocardiographic changes, cardiac tamponade, congestive heart failure, edema, aggravation of hypertension, aggravation of coronary artery disease

Most of the cases of cardiovascular effects reported have occurred in patients receiving carbamazepine for trigeminal neuralgia. The reported effects included congestive heart failure, edema, hypotension, syncope and arrhythmias. In general, the doses were titrated quickly because of severe pain. Many of the doses were higher than those used to treat epilepsy. Many of the reported cardiovascular effects resolved after discontinuation of carbamazepine.

Increased sympathetic activity in the setting of seizure-induced hypoxia could predispose a patient to sudden unexpected death in epilepsy (SUDEP).

Nervous system

Rigidity and oculogyric crises have been reported. Euphoria has also been reported and has led to abuse of carbamazepine in some patients. Impairment of psychomotor function has been noted in association with use of the liquid suspension of carbamazepine. Additionally, impaired cognition, exacerbations of focal seizures and asterixis have been reported in association with carbamazepine treatment. One case of a lingual-facial-buccal extrapyramidal reaction has also been described.

One study has suggested that gradual withdrawal of carbamazepine over ten days results in significantly fewer generalized tonic-clonic seizures compared to rapid withdrawal over four days.

One study has suggested that the epoxide metabolite of carbamazepine may be responsible for the occasional occurrence of seizure exacerbations in patients receiving carbamazepine.

Very common (10% or more): Dizziness (44%), somnolence (32%), ataxia (15%)
Common (1% to 10%): Asthenia (8%), speech disorder (6%), tremor (3%), twitching (2%), vertigo (2%)
Frequency not reported: Drowsiness, disturbances of coordination, confusion, headache, fatigue, neuroleptic malignant syndrome, fever and chills, suicidal behavior and ideation, confusion, speech disturbances, abnormal involuntary movements, tinnitus

Hypersensitivity

Frequency not reported: Multiorgan hypersensitivity reactions occurring days to weeks or months after initiating treatment

Rash and pruritus often resolve after discontinuation of carbamazepine therapy. Both cases of lupus-like syndrome resolved after discontinuation of carbamazepine. Stevens-Johnson syndrome, erythema multiforme, and a mononucleosis-like syndrome have also been reported.

Hepatic

Frequency not reported: Abnormalities in liver function tests, cholestatic and hepatocellular jaundice, hepatitis, very rare cases of hepatic failure

Alterations in liver function tests may progress to hepatotoxicity including cholangitis, granuloma formation, fever and hepatocellular necrosis. Discontinuation of carbamazepine often results in improvement in laboratory abnormalities and liver injury.

Renal

Frequency not reported: Renal failure

Respiratory

Frequency not reported: Pulmonary hypersensitivity characterized by fever, dyspnea, pneumonitis, or pneumonia

Dermatologic

Dangerous, sometimes fatal skin reactions (Stevens Johnson syndrome and toxic epidermal necrolysis), that can be caused by carbamazepine therapy are significantly more common in patients with the human leukocyte antigen (HLA) allele, HLA-B 1502. This allele occurs almost exclusively in patients with ancestry across broad areas of Asia, including South Asian Indians. Patients with ancestry from areas in which HLA-B 1502 is present should be screened for the HLA-B 1502 allele before starting treatment with carbamazepine. If these individuals test positive, carbamazepine should not be started unless the expected benefit clearly outweighs the increased risk of serious skin reactions. Patients who have been taking carbamazepine for more than a few months without developing skin reactions are at low risk of these events ever developing from carbamazepine. This is true for patients of any ethnicity or genotype, including patients who test positive for HLA-B 1502.

Common (1% to 10%): Pruritus (8%), rash (7%), paresthesia (2%)
Rare (less than 0.1%): Alopecia (0.01%)
Frequency not reported: Toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome, unusual bruising, pruritic and erythematous rashes, urticaria, photosensitivity reactions, alterations in skin pigmentation, exfoliative dermatitis, erythema multiforme and nodosum, purpura, aggravation of disseminated lupus erythematosus, alopecia, diaphoresis, onychomycosis

Ocular

Common (1% to 10%): Blurred vision (6%)
Postmarketing reports: Diplopia, oculomotor disturbances, nystagmus, photosensitivity, blurred vision, visual hallucinations, transient diplopia, scattered punctate cortical lens opacities, increased intraocular pressure as well as conjunctivitis

Oncologic

Frequency not reported: Disorders mimicking lymphoma

Immunologic

Postmarketing reports: One case of aseptic meningitis, with myoclonus and peripheral eosinophilia, was reported in a patient taking carbamazepine in combination with other medications. The patient was successfully dechallenged, and the meningitis reappeared upon rechallenge with carbamazepine

Psychiatric

Common (1% to 10%): Abnormal thinking (2%)
Frequency not reported: Depression with agitation, talkativeness

Genitourinary

Frequency not reported: Urinary frequency, acute urinary retention, oliguria with elevated blood pressure, azotemia, renal failure, impotence, albuminuria, glycosuria, elevated BUN, and microscopic deposits in the urine, rare reports of impaired male fertility and/or abnormal spermatogenesis

Metabolic

Frequency not reported: Inappropriate antidiuretic hormone (ADH) secretion syndrome, water intoxication, with decreased serum sodium (hyponatremia) and confusion

Musculoskeletal

Postmarketing reports: Aching joints and muscles, leg cramps

Other

Postmarketing reports: Lupus erythematosus-like syndrome, hyperacusis

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