Carbamazepine for RLS
Clinical bottom line
Carbamazepine has been used in one good trial and proved to be more effective than placebo.
Reference
W Telstad et al. Treatment of the restless legs syndrome with carbamazepine: a double blind study. BMJ 1984 288: 444-446.
Clinical trial
This was a properly randomised and double blind trial comparing carbamazepine and placebo over five weeks. Doses began with 100 mg carbamazepine or equivalent daily, for one week, with a titration up to 300 mg daily over weeks 2-3, and stable dosing over weeks 4-5.
The main outcome was the number of RLS attacks per week.
Results
There were 181 patients in the trial. All but three had two or more attacks of RLS per week at baseline, with most having daily or almost daily attacks. The number and frequency of attacks fell both with carbamazepine and placebo, but the reduction was greater with carbamazepine (Figure 1) than with placebo (Figure 2; Table 1). At five weeks, 61% had no or one RLS attack per week with carbamazepine, compared with 40% with placebo.
Figure 1: RLS attacks per week before and after carbamazepine
Figure 2: RLS attacks per week before and after placebo
Table 1: Details of trial
| Telstad et al, BMJ 1984 288: 444-446 | R = 1 DB = 2 WD = 1 QS = 4 Parallel group Duration = five weeks |
Treatments 1 Carbamazepine up to 300 mg daily (84) 2 Placebo (90) Outcomes: Attacks of RLS each week |
Groups matched for age and sex, and concomitant disease. More women
than men enrolled. Same duration of RLS and Hb Mean age 52 (range 17-86) |
Initially almost all patients had more than 2 attacks of RLS per week At week 3, 0 or 1 attack/week 43/84 carbamazepine 29/90 placebo At week 5, 0 or 1 attack/week 51/84 carbamazepine 36/90 placebo Significant improvement for carbamazepine over placebo |
Any AE 34/84 carbamazepine 20/90 placebo AE withdrawals 6/84 carbamazepine 2/90 placebo |
Adverse events occurred more commonly with carbamazepine, but no serious adverse events were described, though eight people withdrew from the study because of adverse events (Table 1).
Comment
On the basis of this single trial, carbamazepine appears to have some efficacy, at least over the short term.