Nov 9 2012
By Sarah Guy, medwireNews Reporter
Melatonin increases the length of time spent asleep and reduces the time it takes to get to sleep for children with neurodevelopmental disorders, compared with placebo, show study results published in the British Medical Journal.
The phase III trial took place over 12 weeks among children aged 3 to 15 years with conditions including autism, epilepsy, and developmental delay, note the researchers.
Treatment doses were escalated to a total of 12.0 mg from the initial 0.5 mg if participants continued to fit the criteria for sleep disorder, defined as failing to fall asleep within an hour of bedtime in three nights out of five, or achieving less than 6 hours per night of continuous sleep over the previous 5 months.
The final analysis included 66 children who were randomly assigned to receive melatonin and 70 children who were assigned to placebo.
The team found that melatonin increased the total sleep duration by a significant 22.4 minutes as recorded in sleep diaries, and 13.3 minutes as recorded by actigraphy.
While statistically significant, however, neither group achieved the 60-minute value determined to be the clinically relevant minimum for improvement, note Paul Gringras (St Thomas' Hospital, London, UK) and colleagues.
Children in the melatonin group also had a significantly reduced sleep latency, taking a mean 37.5 and 45.3 minutes less to get to sleep compared with baseline as measured by sleep diary and actigraphy, respectively. Both of these figures cross the 30-minute threshold considered to be clinically significant.
Adverse events included coughing (31.4% melatonin; 36.8% placebo); mood swings (22.9% melatonin; 22.4% placebo); vomiting (21.4% melatonin; 23.7% placebo), and increased excitability (18.6% melatonin; 21.1% placebo). While seven serious adverse events were also reported, only two of these were related to the treatment drug, note the authors.
Interestingly, they remark, children taking melatonin woke up an average of 29.9 minutes earlier at the 12-week follow up compared with those in the placebo group after adjustment for baseline waking times.
This observation suggests that "evening exogenous melatonin advances sleep phase over time and therefore children fall asleep earlier but also wake earlier, explaining the smaller effect on total sleep time," than expected, write Gringras et al.
"Our findings provide valuable evidence about the dosing, tolerability, and effect of using melatonin in children with neurodevelopmental and sleep disorders," they conclude.
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