Hematological effects carbamazepine

Joffe RT, Post RM, Roy-Byrne PP, et al. Hematological effects of carbamazepine in patients with affective illness. Am J Psychiatry 1985 142 1196-1199. 

Adverse Effects Adverse effects due to oxcarbazepine include drowsiness, dizziness, gastrointestinal upset, and hyponatremia, the latter two of which may be more likely than with carbamazepine. It is less likely than carbamazepine to cause hematologic abnormalities.34... 

Leukopenia is the most common hematologic side effect (up to 10%) but is usually transient. It may be persistent in 2% of patients. Carbamazepine may... 

Carbamazepine. The anticonvulsant carbamazepine was actually the first to be shown to be effective in the manic phase of bipolar disorder, but it has not been approved for this use by regulatory authorities such as the U.S. Food and Drug Administration (FDA). Its mechanism of action may be to enhance GABA function, perhaps in part by actions on sodium and/or potassium channels (Fig. 7—24). Because its efficacy is less well documented and its side effects can include sedation and hematological abnormalities, it is not as well accepted for first-line use in the treatment of mood disorders as either lithium or valproic acid. 

As with carbamazepine, phenytoin also causes idiosyncratic toxic effects, including hematological and connective tissue toxicities, hepatotoxicity, and teratogenicity (89). Although some of these toxicities have been hypothesized to be caused by P450 oxidative metabolism (92,93) or peroxidase-mediated reactions (94,95), mechanisms for these toxic effects in humans are unknown. 

The therapeutic concentration range for optimal pharmacological effect of carbamazepine is 4 to 12p,g/mL. Toxicity associated with excessive carbamazepine ingestion occurs at plasma concentrations in excess of 15p.g/mL and is characterized by symptoms of blurred vision, paresthesia, nystagmus, ataxia, drowsiness, and diplopia. Side effects unrelated to plasma concentration include development of an urticarial rash, which usually disappears on discontinuation of the drug, and hematological depression (leukopenia, thrombocytopenia, and aplastic anemia). 

Thrombocytopenia and anemia are relatively rare events that usually respond to discontinuation of the offending drug. Leukopenia is the most common hematologic side effect. An incidence as high as 10% has been reported. Leukopenia usually is transient, even when the drug is continued, and may be due to a redistribution of white blood cells (WBCs) rather than a decrease in their production. In about 2% of patients, the leukopenia is persistent, but even patients with WBC counts of3000/mm or less do not seem to have an increased incidence of infection. A clinical guide is to continue carbamazepine therapy unless the WBC count drops to less than 2500/mm and the absolute neutrophil count drops to less than 1000/mm. " ... 

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