Erythema multiforme carbamazepine

An exanthematous rash is one of the more common side effects of carbamazepine, occurring in 3%-17% of patients. This reaction typically begins within 2-20 weeks after the start of treatment. Car-bamazepine is generally discontinued if a rash develops because of the risk of progression to an exfoliative dermatitis or Stevens-Johnson syndrome, a severe bullous form of erythema multiforme. 

Hypersusceptibility reactions to carbamazepine are relatively common and range from cutaneous reactions (including Stevens-Johnson sjmdrome and toxic epidermal necrolysis, severe forms of erythema multiforme) to systemic reactions with fever, lymphadenopathy, and/or involvement of the bone marrow, the liver, the heart, the gastrointestinal system, the lungs, and other organs. 

Sulfonamides, penicillins, diclofenac, oxyphenbutazone, piroxicam, phenytoin, carbamazepine (Same as for erythema multiforme) penicillamine, captopril, piroxicam, penicillins, rifampicin Frusemide, penicillamine, penicillin, PUVA therapy Immunosuppressants, mexiletine, thioridazine, penicillamine, moduretic , atenolol, quinacrine... 

The following drugs have been most often associated with erythema multiforme and Stevens-Johnson syndrome allopurinol, lamotrigine phenytoin, barbiturates, carbamazepine, estrogens/progestins, gold, NSAIDs, penicillamine, sulfonamides, tetracycline, and tolbutamide. 

An isolated report describes a 26-year-old woman with cerebral palsy who had been taking phenobarbital 15 mg with carbamazepine 400 mg daily for 12 years to control epilepsy, and who developed fatal toxic epidermal necrolysis 2 weeks after starting oral terbinafine 250 mg daily for tinea corporis. The reasons are not understood, but the authors point out that all three drugs can cause adverse skin reactions (erythema multiforme) and suggest that some synergism may have occurred. It is uncertain whether this was a true interaction or a terbinafine adverse effect. 

Three patients treated with various antipsychotics (fluphenazine, ha-loperidol, trifluoperazine, chlorpromazine) developed Stevens-Johnson syndrome within 8 to 14 days of starting to take carbamazepine. All 3 had erythema multiforme skin lesions and at least two mucous membranes were affected. After treatment, all 3 were restarted on all their previous drugs, except carbamazepine, without problems. Another case of Stevens-Johnson syndrome has been reported in a patient taking carbamazepine, lithium carbonate, haloperidol and trihexyphenidyl. The reasons are not understood. Stevens-Johnson syndrome with carbamazepine alone is rare, and the risk appears to be mostly confined to the first 8 weeks of treatment. It may be more common in patients being treated for conditions other than epilepsy. It is not possible to say whether the concurrent use of antipsychotics increases the risk of its development, but until more is known it would be prudent to monitor the outcome, particularly during the first 2 weeks of combined use. 

The risk of erythema multiforme, Stevens-Johnson syndrome, or toxic epidermal necrolysis in 72 patients with bipolar disorder taking carbamazepine, valproate, or other medications has been analysed using a large... 

In a large database study, treatment with valproic acid was significantly associated with erythema multiforme, Stevens—Johnson syndrome, or toxic epidermal necrolysis among patients with bipolar disorder [94 ] (see Carbamazepine for details). 

---