Insomnia is a common problem. Nearly 10% of the adult population suffer from chronic insomnia. Chronic insomnia is defined as symptoms (difficulty falling asleep, difficulty staying asleep or waking up earlier than desired wake time) occurring at least three nights a week and lasting for at least 3 months with impairment in functioning. This proportion increases with age. When these symptoms last for a period shorter than mentioned above (3 months), the disorder is termed “short term insomnia”.
Why do people use OTC sleeping pills?
Several pharmacological and non-pharmacological therapies, such as Cognitive Behavior Therapy for insomnia (CBTi), are available for the management of insomnia. Patients may turn to OTC medications for insomnia for various reasons. There may be inaccessibility and/or affordability to medical care, paucity of sleep-physicians and/or CBTi therapists or long wait times for medical consultation.
OTC sleeping pills
OTC sleeping pills fall into one of three categories of medications.
- Antihistaminic drugs that block histamine receptors to manage allergic conditions. Because the same receptors are blocked in the brain, sleep is induced, a “side” effect to antihistamines. Commonly used OTC medications for insomnia that fall in antihistaminic group include diphenhydramine and doxylamine.
- Melatonin preparations act on melatonin receptors in the brain and are marketed as a food supplement. Melatonin is a normally occurring hormone in the body and its concentration rises in the darkness to induce sleep.
- Valerian an abstract from the roots of its plant. It has been considered a sedative for a long time, though exact mechanism of actions are not known.
Prescription verses non-prescription sleeping pills
Prescription sleeping pills are medications, which are primarily designed to treat insomnia. There is adequate scientific data to support their effectiveness and tolerability for the short-term management of insomnia with acceptable “side effects” profile. These medications belong to three categories:
- Benzodiazepines (e.g., Diazepam, Lorazepam);
- Z-drugs (e.g., Zolpidem, Eszopiclone)
- Dual orexin receptor antagonists (e.g., Suvorexant, Lemborexant, Daridorexant).
Only a small proportion of insomnia patients experience “side” effects, and the “side” effects are considered tolerable by most patients. Hence, these medications were approved for use in insomnia.
OTC sleeping pills were not designed to treat insomnia which means they have not been investigated adequately for their effectiveness and tolerability as medication to treat insomnia.
Is it beneficial to take OTC sleeping pills?
In some patients, but not all, untreated insomnia symptoms may progress to chronic insomnia. Untreated chronic insomnia increases risk for hypertension, diabetes mellitus, dementia, obesity, depression and addiction. It also increases risk of errors, accidents, and worsens quality of life. Considering these issues, it seems imperative to manage insomnia symptoms. Though effectiveness and tolerability of OTC sleeping pills is not established for management of chronic insomnia, they may help some patients, at least till the time a person is able to seek professional advice.
What are the risks of OTC sleeping pills?
Any medication, whether it is allopathic, ayurvedic, or homeopathic, to manage a given symptom or set of symptoms, will act on various cells in the human body. These medications show their effect by binding to its receptors on the cells. For example, Zolpidem binds its receptors in cortical and subcortical areas of the brain that are responsible for inducing sleep.
Unfortunately, receptors of a given agent may be present in multiple cells in different places in the body. Consequently, besides the intended effect, some undesirable effects will also be experienced which are known as “side” effects. For example, receptors of Zolpidem are also present in areas responsible for memory and balance maintenance. Hence, it can cause memory lapses and imbalance as a “side” effect. Even prescription sleeping pills can have some adverse effects in some patients.
One medication may act on multiple receptor systems of different classes to further increase chances of adverse effects*. For example, OTC sleeping pills like Diphenhydramine and Doxylamine block histamine receptors, but they also block cholinergic receptors. Blockade of these additional receptors can produce dry mouth, urinary retention, constipation, increase heart rate, glaucoma and impaired memory. If a person has inherently higher risk (owing to age, other medical conditions, concomitant medications) for any of these conditions, antihistamines can either precipitate or worsen it. Similarly, headache, nausea, drowsiness and nightmares have been reported after melatonin use. Valarian can also induce headache and weakness.
Should I take OTC sleeping pills?
Since they are not designed to treat insomnia, scientific data is not available regarding their effectiveness and tolerability. They may have multiple “side” effects and should best be avoided.
Ravi Gupta MD, PhD, Professor, Department of Psychiatry and Division of Sleep Medicine at All India Institute of Medical Sciences, Rishikesh, India. He specializes in insomnia, sleep apnea, and restless legs syndrome.
*https://commons.wikimedia.org/wiki/File:Ligand-receptor_interaction.png
