In this study, we compared the efficacy and safety of melatonin and naproxen in patients with menstrual-related migraines. The number of migraine attack days and the severity of migraine pain in the two groups improved significantly, and the decreasing trend overtime was the same in the two groups. This finding shows that melatonin is as effective as naproxen in reducing the number of migraine-related menstrual attacks. Treatment with naproxen or melatonin made a significant difference in the number of sedative/abortive drugs used in each attack, which was lower in the melatonin group. Melatonin also had a beneficial effect on reducing sleep problems such as the rate of snoring and the severity of subjective tiredness after sleep. The most reported adverse drug reactions in melatonin-treated patients were dizziness (54%), post-sleep fatigue (38.5%), inattention (38.5%), and GI problems (15%).
Similar to the results of the current study, the first pilot study of melatonin in 2004 for migraine cases showed a significant decrease in headache attacks in 64.7% of the patients. In the first month, a complete response to treatment was achieved in 25% of the patients. They reported a significant reduction in the attack rate and duration, pain severity, and the number of sedative drug use in patients. The reported side effects in the study included daytime sleepiness and alopecia (
13).
Another randomized clinical trial, designed to investigate the effect of melatonin as a prophylactic treatment on migraine and its role in sleep quality of patients, demonstrated the superiority of melatonin to placebo in reducing the frequency of migraine attacks. However, this study did not show a significant effect on sleep quality (
15). It is important to note a few points about different treatment responses reported by the aforementioned study compared to the current reported results. First, the dose of melatonin used in this study was 2 mg versus 3 mg in our study. Second, the baseline number of patients’ migraine attack days per month was lower in this study (4.2) than in ours (7.5). Third, in this study, the control group received a placebo while our study patients received naproxen, a known drug for the prophylactic treatment of menstrual-related migraine (
15). In another similar study, a pilot trial was performed on 49 different primary type headache patients (37 with migraine headaches and 12 with tension headaches), which showed that treatment with melatonin (4 mg half an hour before sleep) for six months significantly reduced the attack frequency in patients compared to baseline (
16). A recent systematic review study focused on melatonin as a prophylactic treatment for migraine (
14). A total of seven studies were eligible although due to heterogeneity and the low number of patients, a meta-analysis was not performed. The authors claimed that because of contradictory results of the studies, the beneficial role of the melatonin treatment in migraine attacks could not be proven, but the treatment regimen with melatonin at a dose of 3 mg for intervals of three months appeared to show promising results (
14).
There are limited data about the role of melatonin in migraine and menstrual-related headaches. Melatonin has anti-inflammatory properties and leads to a reduction in prostaglandin E production (activator of the trigeminovascular system) and inflammatory cytokines (
17,
18). In addition, melatonin is a neurohormone that can control the vascular response of the brain and lead to vasoconstriction of the brain arteries (
19). Melatonin reduction, therefore, can play a role in triggering migraine headaches. In this regard, trigeminal ganglion contributes to releasing neuropeptides such as substance P (SP) and calcitonin gene-related peptide (CGRP), which are involved in provoking migraine attacks (
20,
21). A study by Ansari et al. revealed that melatonin decreases the expression of CGRP through its effect on the production of nitric oxide via inducible nitric oxide synthase (iNOS) enzyme activity in migraine patients (
22). Furthermore, it has been shown that non-steroidal anti-inflammatory drugs (NSAIDs) also decrease melatonin synthesis in the body, which may lead to possible harmful effects of chronic NSAIDS use, such as naproxen, in migraine patients. The melatonin level significantly increases during the luteal phase of the menstrual cycle, possibly due to the increase of post-ovulatory progesterone. In addition, a study showed that progesterone receptors are present in the bovine pineal gland, which may support the melatonin-progesterone interaction in regulating the menstrual cycles (
8,
9,
11,
23,
24). Physiological changes in the menstrual cycle have not been found in migrainous women, which may influence the attack severity during the menstrual phase (
11). The fluctuation of the pain threshold and a dose-related analgesic effect for melatonin are shown in experimental animals, such as mice, and it may reflect the role of the pineal gland in the determination of the light-dark-linked circadian rhythm in the body (
25). Therefore, the administration of melatonin in menstrual-related migraines may be effective in relieving attacks by interfering with hormonal and circadian rhythm changes.
In this study, sleep quality factors like snoring and post-sleep tiredness improved after melatonin treatment compared to pre-treatment. Therefore, there is a potential role for melatonin in improving the sleep quality of patients with menstrual-related migraines. Melatonin also showed beneficial effects on sleep quality in two other studies by Peres et al. (
13,
25). They also previously reported the significant effect of sleep disturbances on migraine chronobiologic features in chronic or episodic types and showed that 46.5% of the patients experience headaches after changing their sleep schedule. A significant shift in the duration of sleep was observed in patients, ranging from -2.5 to +5 h. Most patients (69%) had a delayed sleep phase, whereas 31% slept earlier (
18). Both episodic and chronic migraine cases reported waking up in the morning or being woken up during the night by headaches, and a significant number of migraine attacks occurring in the morning period were attributed to sleep disorders (
26,
27). Although a few studies have looked into the effects of melatonin treatment on the sleep quality of migraine patients, their results generally suggest the lack of effectiveness in patients without sleep disorders (
15).
Our results showed that the number of sedative drug use was significantly lower in the melatonin group than in the naproxen group. Although naproxen is the treatment of choice for menstrually related migraine, it has been shown that non-steroidal anti-inflammatory drugs (NSAIDs), which reduce pain via prostaglandin synthesis inhibition, may also decrease melatonin synthesis (
28).
Therefore, we conclude that melatonin could be considered a potential treatment for menstrual-related migraines, with an effectiveness comparable to that of naproxen in reducing attacks. In addition, our study showed lower rates of medication overuse headaches and sleep problems in the melatonin treatment group than in the naproxen group, which are two challenging problems for physicians in managing chronic migraine patients. It is also an alternate treatment for patients when there is a contraindication for using NSAIDs. However, the number of cases and the lack of a placebo arm are the two limitations of the trial, which should be considered in future investigations of the role of melatonin as a potential treatment in women with menstrually related migraine headaches.