Weaknesses:

Strong pharmacokinetic interaction with many other medications

• Carbamazepine has antimanic efficacy but is rarely advocated for first line treatment. Carbamazepine is not the optimal partner for combination therapy because its liver-enzyme inducing properties may reduce the levels of other drugs, which in turn, may inhibit the catabolism of carbamazepine. [BAP Guidelines]

Risk of agranulocytosis (clinical vigilance and periodic blood counts are prudent)

• Up to 50% of patients receiving carbamazepine experience side effects and the drug is associated with potentially serious adverse reactions.  [APA Guidelines]

Risk of skin rash (similar to lamotrigine)

• Up to 50% of patients receiving carbamazepine experience side effects and the drug is associated with potentially serious adverse reactions. [APA Guidelines]

GSK counterclaim:

Less effective in treating depression compared with mania

• While unlikely to provoke a manic switch, lithium, valproate, and carbamazepine have inadequate evidence for acute antidepressant efficacy.  [BAP Guidelines]