Dr. Vimalkumar Dixit; SGRR medical college, Dehradun
Nocturia is one of the most bothersome and difficult to treat symptom especially in an elderly patient. The mainstream medications such as alpha blockers and antimuscarinics have minimal effects on nocturia and desmopressin, typically approved for this indication only, tends to have significant adverse event potential, especially in elderly. Thus there is an unmet need of safe and effective medical therapy in patients with nocturia.
Figure 1 - mechanism of melatonin in nocturia
Melatonin supplementation has emerged as a potential therapeutic option for managing nocturia. Melatonin, often referred to as the "hormone of darkness," is primarily synthesized and released by the pineal gland in response to darkness. It plays a key role in regulating the body's circadian rhythm, including the timing of sleep-wake cycles. Melatonin levels typically rise in the evening, promoting relaxation and sleep, and decline in the morning, allowing wakefulness to occur. Disruptions in the circadian rhythm, such as nocturnal awakenings to void, can lead to nocturia. Besides, exogenous melatonin has been proposed to have central GABAergic action that inhibits central micturition pathways and also inhibits detrusor muscle via direct as well as MT2 mediated action. It also has antioxidant and anti-inflammatory properties that may contribute to its benefits in managing nocturia.(1)
Although melatonin is widely available as an over-the-counter supplement, it's essential to note that it is not FDA-approved as a treatment for nocturia. Instead, it is classified as a food supplement. Despite this classification, clinical trials investigating melatonin for nocturia have shown promising results. Randomized controlled trials have demonstrated reductions in nocturia episodes and improvements in sleep quality with melatonin supplementation compared to placebo.(2) A recent meta-analysis showed that the majority of the studies assessing melatonin in Nocturia report a >1/night reduction in the nocturia episodes, although a meta-analysis was not possible due to heterogeneity in the baseline diagnoses.(3) It also improved the duration of first interrupted sleep by 1hr as well as imporved the quality of life.(4) The recommended dose of melatonin typically ranges from 2 to 10 mg taken orally before bedtime.
However, melatonin supplementation isn't without side effects. Common ones include drowsiness, headache, dizziness, and gastrointestinal disturbances. It may also interact with medications such as anticoagulants and sedatives.(5)
Further research is required to determine optimal dosing, long-term safety, and efficacy across patient populations. Despite the need for more evidence, melatonin offers a promising adjunctive therapy for nocturia management, particularly in cases where lifestyle modifications and pharmacological treatments have provided inadequate relief.
Key points
Melatonin: Nocturia |
Melatonin circadian rhythm regulates sleep-wake cycle |
Improves duration of first interrupted sleep |
Reduces Nocturia episodes by 1/night |
Dose 2-10mg /day |
Not FDA approved for Nocturia |