Lamotrigine, skin rashes

Lamotrigine, skin rashes, 20.62, 24.88 Latex, allergy, 31.761 Laxatives, abuse, 13.336 Leflunomide, 29.435 Leukotriene receptor antagonists,... 

Severe skin rashes appear to be the major concern with lamotrigine use. The incidence of rash is greater in children than in adults. Other adverse effects are similar to those of drugs with the same mechanism of action, such as cerebellovestibular changes leading to dizziness, diplopia, ataxia, and blurred vision. Disseminated intravascular coagulation has been reported. 

Wong 1C, Mawer GE, Sander JW. Factors influencing the incidence of lamotrigine-related skin rash. Ann Pharmacother 1999 33 1037-1042. 

With phenytoin, carbamazepine, phenobarbital, primidone, and lamotrigine, hepatotoxicity usually occurs as part of a hypersensitivity reaction, with skin rashes and fever in the early weeks of treatment. More rarely, hepatic disease can develop after many years without signs of hypersensitivity. Once hepatotoxicity develops, mortality... 

Lamotrigine has been stndied in 32 children with epilepsy refractory for at least 1 year to other antiepileptic drugs (7). Adverse effects were uncommon, and there were no skin rashes. 

The efficacy and safety of lamotrigine have been prospectively evaluated in 41 children and yonng adults (aged 3-25 years) with drug-resistant partial epilepsies (8). Lamotrigine withdrawal was mainly due to lack of efficacy (46%) only two patients developed a transient skin rash, which did not require withdrawal. 

Although serious skin rashes have been reported with traditional anticonvulsants, the risk of Stevens-Johnson syndrome and toxic epidermal necrolysis with these drugs appears to be lower than with lamotrigine. Data from the Saskatchewan Health Plan suggest that the risk of serious rashes is in the order of 0.9 1000 (1.4 1000 in children) for phenytoin, 0.6 1000 (1.4 1000 in children) for carbamaze-pine, and 0 1000 for valproate, but Stevens-Johnson syndrome constituted only a small minority of these cases (47). 

A phenytoin-like hypersensitivity syndrome with skin rash, leukocytosis, and laboratory evidence of liver and kidney dysfunction has been attributed to lamotrigine (SEDA-22, 89). 

A 49-year-old man with bipolar disorder inadvertently took four daily doses of lamotrigine 2700 mg each. He developed a low-grade fever, a skin rash, and periorbital edema. He had a leukocytosis, raised liver enzymes, and acute renal insufficiency. He recovered fully after lamotrigine withdrawal and steroid therapy. 

The serum levels of lamotrigine can be markedly increased by valproate. Concurrent use has been associated with skin rashes, tremor and other toxic reactions. Lamotrigine has been found to cause small increases, decreases or no changes in valproate levels. 

Lamotrigine (Lamictal ) is available as an oral regimen in 25 mg, 100 mg, 150 mg and 200 mg tablets. Only whole tablets are recommended for use and doses should be rounded down to the nearest whole tablet. It is recommended that Lamictal therapy be initiated at low doses and slowly escalated over the first 4 weeks of therapy to minimize adverse side effects such as skin rash (see Table 74.1). 

Fluid balance A 33-year-old woman with focal epilepsy developed angioedema after starting levetiracetam. This patient had previously developed skin rashes while on both phenytoin and lamotrigine [100 ]. 

Skin Lamotrigine-induced drug rash with eosinophilia and systemic symptoms (DRESS) has been reported in a 75-year-old man, with pancreatitis as the first sign of visceral involvement [187 ]. 

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