Anorexia topiramate

Topiramate is recently approved by the FDA for migraine prophylaxis. Dose is initiated at 25 mg/day and increased slowly to minimize side effects, which may include paresthesias, fatigue, anorexia, diarrhea, weight loss, difficulty with memory, and nausea. Kidney stones, acute myopia, acute angle-closure glaucoma, and oligohidrosis have been infrequently reported. 

Side effects. Many of the side effects reported to occur with topiramate have been found in patients receiving other antiepileptic drugs concurrently. Such side effects as ataxia, confusion, dizziness, fatigue, somnolence, memory disturbance, depression and agitation appear to be less frequent in those patients receiving topiramate as a monotherapy. Weight loss has been reported in many patients this effect may be due to drug induced anorexia. Topiramate has proven efficacious in the treatment of severe epilepsy. 

In an open study of the effects of topiramate 100-1600 mg/day in 292 adults (mean age 33 years) with partial and/or generalized seizures previously resistant to antiepileptic drug therapy over 50% of the patients achieved at least a 50% reduction in seizures (1). The most commonly reported adverse events were related to the central nervous system, including headache, difficulty in concentrating, somnolence, anorexia, fatigue, dizziness, nervousness, nausea, confusion, and paresthesia 32% discontinued because of adverse events. 

In a 3-year retrospective review of the use of topiramate in 51 children aged 3-16 years with partial and generalized epilepsy, 15 children had a greater than 50% reduction in their seizure frequency and four became seizure free (4). Adverse effects were reported in 29 patients most were related to behavioral and cognitive difficulties less common effects included anorexia, weight loss, and headache. Topiramate was withdrawn in 25 patients in 20 cases because of adverse effects. 

In a long-term open extension to a double-blind, placebo-controlled trial of topiramate in 83 children with partial-onset seizures, with or without secondary generalization, seizure frequency over the last 3 months of therapy was reduced by at least 50% in 47 children (9). Anorexia was common during long-term therapy. Five children withdrew because of adverse events. 

The response to topiramate has been evaluated in 97 patients with Lennox-Gastaut syndrome in a long-term, open-label extension to a double-blind, placebo-controlled trial (19). The most common adverse events, apart from childhood illnesses, were somnolence and anorexia. 

Topiramate lowers serum bicarbonate by inhibiting carbonic anhydrase. In 20 of 29 children there was a greater than 10% fall in serum bicarbonate after starting topiramate (mean absolute reduction 4.7 mmol/1), but none had significant sjmptoms of metabohc acidosis, except possibly for anorexia in one (44). In another report, mild to moderate metabolic acidosis (bicarbonate concentrations, 16-21 mmol/1) developed in three topiramate-treated patients aged 25-51 years the condition was not considered clinically significant, but it led to diagnostic tests to exclude other causes (45). 

The most common side-effects of topiramate are paresthesia (27%), headache (21%), fatigue (20%), dizziness (14%), somnolence (1 3%), anorexia (11%), and weight loss (11 %). Less common side-effects, but with important clinical implications, are depression (7%), difficulty with concentration (7%), and confusion (5%). " As with other anhydrase inhibitors, topiramate has been associated with kidney-stone formation, and the incidence of nephrolithiasis is estimated to be 2-4 times higher than that expected in a similar untreated population. Many of the central nervous system effects of topiramate, including cognitive complaints, can be managed by gradual introduction and dose escalation. ... 

All the available evidence for the use of topiramate as monotherapy in patients with newly or recently diagnosed epilepsy has been examined in a systematic review of three randomized, double-bUnd, controlled trials which recruited more than 1000 patients [302 ]. The most common adverse events associated with topiramate 50-500 mg/day generally occurred early in the course of treatment and were nervous system-related effects headache (15-25%), dizziness (12-19%), fatigue (11-23%), somnolence (10-17%), anorexia (8-10%), insomnia (7—10%), and hyperesthesia (5— 10%). Adverse events that were likely to have been related to the carbonic-anhy-drase activity of topiramate (e.g. paresthesia, changes in serum bicarbonate) were frequent (13-35%) but were not usually considered clinically relevant Renal calculi occurred infrequently (1%). The most frequent adverse events during maintenance therapy were headache (20%), reduced appetite (11%), and weight loss (11%). 

Observational studies In a study of topiramate for intractable childhood generalized epilepsy with epileptic spasms, adverse effects were observed in 13 of 33 patients and included somnolence, anorexia, and irritability. Seizure aggravation was observed in six patients [16(P]. 

The long-term effects of topiramate on adaptive behavior in infants with epilepsy were assessed [161 ]. A clinically significant decline in scores on the Vineland Scales of Adaptive Behavior occurred in infants treated with topiramate. Of note, however, Vineland scores were below average at pretreatment baseline in these patients. Anorexia was noted in 35% of patients and somnolence in 27%. 

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