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an antihistamine with sedative and anticholinergic effects; used as the succinate salt in the treatment of nasal, eye, and skin manifestations of allergic reactions, including allergic rhinitis, conjunctivitis, and itching, as an ingredient in cough and cold preparations, and in the short-term treatment of insomnia, administered orally.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


(dox-il-a-meen peer-ih-dox-een ),


(trade name),


(trade name)


Therapeutic: antiemetics
Pharmacologic: antihistamines
Pregnancy Category: A


Treatment of nausea and vomiting during pregnancy that has not responded to conservative management.


Combination of an antihistamine and a vitamin B6 analog. Mechanism not known.

Therapeutic effects

Decreased nausea and vomiting associated with pregnancy.


Absorption: Well absorbed following oral administration. Food delays/decreases absorption.
Distribution: Doxylamine probably enters breast milk
Metabolism and Excretion: Doxylamine is mostly metabolized by the liver, inactive metabolites are renally excreted. Pyridoxine is a pro-drug, converted to its active metabolite by the liver.
Half-life: Doxylamine—12.5 hr; pyridoxine—0.4–0.5 hr

Time/action profile (anti-emetic effect)

POunkunk8–24 hr


Contraindicated in: Hypersensitivity to doxylamine or pyridoxineConcurrent use of MAOIs Lactation: Doxylamine probably enters breast milk and may cause irritability, excitement, or sedation in infants; breast feeding should be avoided.
Use Cautiously in: AsthmaIncreased intraocular pressure or narrow angle glaucomaStenosing peptic ulcer or pyloroduodenal obstructionUrinary bladder-neck obstruction Pediatric: Safe and effective use in children <18 yr has not been established

Adverse Reactions/Side Effects

Central nervous system

  • drowsiness (most frequent)


Drug-Drug interaction

↑ risk of CNS depression with other CNS depressants including alcohol, other antihistamines, opioid analgesics, and sedative/hypnotics Concurrent use of MAOIs ↑ intensity/duration of adverse CNS (anticholinergic) reactions


Oral (Adults) Day 1—Two tablets (doxylamine 10 mg/pyridoxine 10 mg) at bedtime, if symptoms are controlled continue this regimen; Day 2, if symptoms persist into afternoon on day 2—two tablets at bedtime on day 2 and then one tablet in the morning on day 3 and two tablets in the evening, if symptoms are controlled, continue this regimen; Day 4, if symptoms persist—one tablet in the morning, one tablet mid-afternoon and two tablets at bedtime (not to exceed four tablets daily).


Delayed-release tablets: doxylamine 10 mg/pyridoxine 10 mg

Nursing implications

Nursing assessment

  • Assess for frequency and amount of emesis daily during therapy. Reassess need for medication as pregnancy progresses.

Potential Nursing Diagnoses

Nausea (Indications)
Risk for injury (Adverse Reactions)


  • Oral: Administer on an empty stomach with a full glass of water; food delays onset of medication. Swallow tablets whole; do not crush, break, or chew.

Patient/Family Teaching

  • Instruct patient to take as directed.
  • May cause drowsiness. Caution patient to avoid driving and other activities requiring alertness until response to medication is known.
  • Advise patient to avoid alcohol and CNS depressants, including sedatives, tranquilizers, antihistamines, opioids, and some cough and cold medications with doxylamine pyridoxine.
  • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications.
  • Advise female patient to avoid breast feeding during therapy.

Evaluation/Desired Outcomes

  • Decrease in frequency of nausea and vomiting during pregnancy.
Drug Guide, © 2015 Farlex and Partners
References in periodicals archive ?
consider the popular diphenhydramine and doxylamine as ingredients for sleep aids.
Dimenhydrinate, Meclizine, and Doxylamine. Dimenhydrinate, meclizine and doxylamine are antihistamines from the group of [H.sub.1] blockers.
(d) Diphenhydramine, doxylamine, dexchlorpheniramine, chlorpheniramine, promethazine, desloratadine, cyproheptadine, loratadine, fexofenadine, hydroxyzine, pheniramine, dimetindene.
There are two in this category, diphenhydramine (such as Benadryl), and doxylamine (Unisom Nighttime Sleep Aid).
The drug is a combination of the antihistamine doxylamine and vitamin [B.sub.6].
Antihistamines such as Diphenhydramine and Doxylamine are also sedative.
Contains (per tablet): 450mg paracetamol, 10mg codeine phosphate, 5mg doxylamine succinate, 30mg caffeine
Originally, Bendectin consisted of dicyclomine hydrochloride to stop or prevent spasms, doxylamine succinate, which was the antihistamine, and pyridoxine, also known as Vitamin B6.
* Heath Ledger: The actor died on Jan.&nbsp;22, 2008, at the age of 28 due to acute intoxication by the combined effects of oxycodone, hydrocodone, diazepam, temazepam, alprazolam&nbsp;and doxylamine.
In the 1970s, a lot of that litigation centered around the morning sickness drug Bendectin--originally formulated with doxylamine succinate, pyridoxine HCl, and dicyclomine HC1, and later reformulated without the dicyclomine.