Over-the-Counter Medications

Antihistamines

Antihistamines are the most commonly used over the counter medication for sleep. These medications are safe; however they have a number of side effects, such as next day drowsiness, poor motor skills, blurred vision, dry mouth, dry eyes, constipation and urinary retention.

Melatonin

Melatonin is a hormone secreted by the pineal gland and is believed to bring on sleep. Although the effectiveness of melatonin remains controversial, it has received attention in the treatment of insomnia caused by jet lag and shift work. In these situations, melatonin is believed to help one adapt the new daily schedule. No serious adverse effects have been reported from the short-term use of melatonin; however, no systematic long-term studies have been reported. Although melatonin occurs naturally in the body, a number of side effects are associated with taking it as a medication. They have been sleep disruption, daytime fatigue, headache, dizziness and increased irritability. In addition, standards of quality regarding purity, concentration and absence of harmful impurities are not regulated for melatonin in they same manner that they are for prescription products. While the use of melatonin for short-term adaptation to jet lag or shift changes appears reasonable, there is little basis for recommending its use for other forms of insomnia until further studies have been completed.