R06AA09 - Doxylamine |
Propably not porphyrinogenic |
PNP |
Rationale
No evidence of CYP3A4 or CYP2C9 induction in humans. Substrate for CYP2D6, CYP1A2, and CYP2C9. No CYP-related drug-drug interactions noted.
Chemical description
Doxylamine is an ethanolamine antihistamine (DrugBank).
Therapeutic characteristics
Doxylamine is used to treat insomnia and allergy symptoms but is increasingly used in combination with pyridoxine in the treatment of nausea and vomiting in pregnancy (DrugBank).
It is taken orally, as a single 25 mg dose at bedtime when used as a sleep aid, or up to four tablets containing 10 mg doxylamine may be taken in three divided doses when used in combination with pyridoxine for the treatment of nausea and vomiting of pregnancy (DrugDex, SmPC)
Metabolism and pharmacokinetics
Doxylamine is biotransformed in the liver primarily by the cytochrome P450 enzymes CYP2D6, CYP1A2, and CYP2C9, to its principal metabolites N-desmethyl-doxylamine and N,N-didesmethyldoxylamine (SmPC).
Doxylamine has showed a marked induction of CYP2B enzymes and a modest induction of CYP3A and CYP2A in mice (Bookstaff 1996) However, there is no evidence that doxylamine is an enzyme inducer of either CYP2C9 or CYP3A4 in humans (IARC 2001).
No CYP-related drug interactions are noted in the interactions databases.
Published experience
No case reports found.
Similar drugs
References
| # | Citation details | PMID |
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| * | Scientific articles | |
| 1. | Effects of doxylamine succinate on thyroid hormone balance and enzyme induction in mice.
Bookstaff RC, Murphy VA, Skare JA, Minnema D, Sanzgiri U, Parkinson A. Toxicol Appl Pharmacol. 1996; 141(2): 584-94. doi:10.1006/taap.1996.0325 |
8975784 |
| * | Drug reference publications | |
| 2. | DrugBank. Doxylamine. (Accessed: 26 August 2025).
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| * | Drug interaction databases | |
| 3. | Doxylamine succinate. In: Merative™ Micromedex® DRUGDEX® (electronic version). Ann Arbor, Michigan, USA: Merative. (Accessed: 26 August 2025).
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| 4. | Merative™ Micromedex® Drug Interaction Checking (electronic version). Ann Arbor, Michigan, USA: Merative. (Accessed: 26 August 2025).
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| 5. | Preston, C.L. (ed). Stockley’s Interaction Checker. London: Pharmaceutical Press. (Accessed: 26 August 2025).
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| * | Summary of Product Characteristics | |
| 6. | Summary of Product Characteristics (SmPC). Xonvea 10 mg / 10 mg gastro-resistant tablets (pyridoxine hydrochloride, doxylamine succinate). Exeltis UK Ltd. Date of revision of text: 26 February 2024. (Accessed: 26 August 2025).
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| * | Other sources | |
| 7. | International Agency for Research on Cancer (IARC) Summary & Evaluation.
Doxylamine Succinate. 2001; 79: 145. Available from: https://www.inchem.org/documents/iarc/vol79/79-05.html (Accessed 27 August 2025). |
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Tradenames
Doxylamine 
Dormidina Doxilamina · Dormigen · Dormikern · Dormirel · Dormirel Forte · Dornite · Doxidina · Doxilamina · Doximax · Dulsueños · Normodorm · Soñodor Doxilamina 
Hoggar 
Dormidina doxilamina · Zonat 
Doksylamina · Dorminox · Doxylamina · Doxylamine · Nitedor · Noctis · Noctis Forte · Senamina · Senamina Forte · Sentino · SENTINO Forte · Sonoxen · Sonoxen FORTE 
Dozile · Mereprine 
Dormix 
Dorlam · Doxylamine 
Calmesan 
Calmesan · Hoggar 
Hoggar 
Doksilamin · Noctiben