Doxylamine was first described in 1948 or 1949. Several of the first-generation antihistamines, including doxylamine, are the most widely used sleep medications in the world. Doxylamine is also a potent anticholinergic, which means it also works as a deliriant at much higher than recommended doses as a result. Its sedative and deliriant effects have led to some cases of recreational use.
The first-generation sedating antihistamines diphenhydramine, doxepin, doxylamine, and pyrilamine are the most widely used medications in the world for preventing and treating insomnia. As of 2004, doxylamine and diphenhydramine, which are both over-the-counter medications, were the agents most commonly used to treat short-term insomnia. As of 2008 and 2017, over-the-counter antihistamines were not recommended by the American Academy of Sleep Medicine for treatment of chronic insomnia "due to the relative lack of efficacy and safety data". Neither version of their guidelines explicitly included or mentioned doxylamine, although diphenhydramine was discussed. A 2015 systematic review of over-the-counter sleep aids including doxylamine found little evidence to inform the use of doxylamine for treatment of insomnia.
Doxylamine is a first-generation antihistamine and was discovered by Nathan Sperber and colleagues and was first reported in 1948 or 1949. It has been the antihistamine component of NyQuil since 1966.
Bendectin, a combination of doxylamine, pyridoxine (vitamin B6), and dicyclomine (an anticholinergicantispasmodic agent), was marketed for treatment of morning sickness in 1956. This product was reformulated in 1976 to remove dicyclomine. The reformulated product was voluntarily discontinued by the manufacturer in the United States in 1983 due to concerns about an alleged association with congenital limb defects. However, these concerns have not been supported by studies. In 2013, doxylamine/pyridoxine was reintroduced in the United States under the brand name Diclegis. The combination was not removed from the market in Canada, where it had been marketed since 1979.
In Commonwealth countries, such as Australia, Canada, South Africa, and the United Kingdom, doxylamine is available prepared with paracetamol (acetaminophen) and codeine under the brand name Dolased, Propain Plus, Syndol, or Mersyndol, as treatment for tension headache and other types of pain.
Doxylamine succinate is used in general over-the-counter sleep-aids branded as Somnil (South Africa), Dozile, Donormyl, Lidène (France, Russian Federation), Dormidina (Spain, Portugal), Restavit, Unisom-2, Sominar (Thailand), Sleep Aid (generic, Australia) and Dorminox (Poland).
In the United States:
Doxylamine succinate is the active ingredient in many over-the-counter sleep-aids branded under various names.
Doxylamine succinate and pyridoxine (Vitamin B6) are the ingredients of Diclegis, approved by the FDA in April 2013 becoming the only drug approved for morning sickness with a class A safety rating for pregnancy (no evidence of risk).
Doxylamine preparations are available typically in combination with pyridoxine that may also contain folic acid. Doxylamine usage is thus restricted for pregnant women.
^ abcPelser A, Müller DG, du Plessis J, du Preez JL, Goosen C (September 2002). "Comparative pharmacokinetics of single doses of doxylamine succinate following intranasal, oral and intravenous administration in rats". Biopharmaceutics & Drug Disposition. 23 (6): 239–244. doi:10.1002/bdd.314. PMID12214324. S2CID32126626.
^ abcdSimons FE, Simons KJ (December 2011). "Histamine and H1-antihistamines: celebrating a century of progress". The Journal of Allergy and Clinical Immunology. 128 (6): 1139–1150.e4. doi:10.1016/j.jaci.2011.09.005. PMID22035879.
^Dupuis G, Vaugeois JM (February 2020). "[The interesting anti-H1 effects in maintenance insomnia: A reflection on the comparative advantages of doxylamine and doxepin]" [The interesting anti-H1 effects in maintenance insomnia: A reflection on the comparative advantages of doxylamine and doxepin]. L'Encephale (in French). 46 (1): 80–82. doi:10.1016/j.encep.2019.01.006. PMID30879783. S2CID151085176.
^Roth BL, Driscol J. "PDSP Ki Database". Psychoactive Drug Screening Program (PDSP). University of North Carolina at Chapel Hill and the United States National Institute of Mental Health. Retrieved 14 August 2017.
^ abcdefghijklmnopqrstKrystal AD, Richelson E, Roth T (August 2013). "Review of the histamine system and the clinical effects of H1 antagonists: basis for a new model for understanding the effects of insomnia medications". Sleep Medicine Reviews. 17 (4): 263–272. doi:10.1016/j.smrv.2012.08.001. PMID23357028.
^ abcdVande Griend JP, Anderson SL (2012). "Histamine-1 receptor antagonism for treatment of insomnia". Journal of the American Pharmacists Association. 52 (6): e210–e219. doi:10.1331/JAPhA.2012.12051. PMID23229983.
^Krystal AD (August 2009). "A compendium of placebo-controlled trials of the risks/benefits of pharmacological treatments for insomnia: the empirical basis for U.S. clinical practice". Sleep Medicine Reviews. 13 (4): 265–274. doi:10.1016/j.smrv.2008.08.001. PMID19153052.
^Kalpaklioglu F, Baccioglu A (2012). "Efficacy and safety of H1-antihistamines: an update". Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry. 11 (3): 230–237. doi:10.2174/1871523011202030230. PMID23173575.