Doxylamine

ATC code

R06AA09

Therapeutic class

First-generation antihistamine, hypnotic · Aminoalkyl ether

Forms

oral tablet

Brand names

Dormigen (ES) · Unisom (US) · Donormyl (FR) · Cariban (ES) · Diclegis (US)

Overall confidence

medium

Regulatory sources consulted

AEMPS-CIMA-FT-83321
CredibleMeds.org
professional-knowledge
AEMPS CIMA · nº registro 83321 ↗

Approved indications

Symptomatic treatment of occasional insomnia in adults.
Nausea and vomiting of pregnancy (NVP), usually in combination with pyridoxine. · off-label

Contraindications

Absolute

Hypersensitivity to doxylamine or other antihistamines.
Angle-closure glaucoma, pyloroduodenal obstruction, bladder-neck obstruction, symptomatic prostatic hypertrophy.
Severe renal or hepatic impairment.

Clinical warnings

Major warning · Anticholinergic effects: may cause drowsiness, dry mouth, blurred vision, and urinary retention. Use with caution in the elderly. — AEMPS CIMA
Major warning · CNS depression: may impair mental and/or physical abilities. Patients should not drive or operate heavy machinery. — AEMPS CIMA

Drug interactions

HighAlcoholV03AB16
Mechanism: Additive potentiation of central nervous system (CNS) depression.
Recommendation: Avoid concomitant use of alcohol.
AEMPS CIMA
HighMonoamine oxidase inhibitors (MAOIs)N06AF
Mechanism: MAOIs prolong and intensify the anticholinergic and CNS depressant effects of antihistamines.
Recommendation: Concomitant use is contraindicated.
AEMPS CIMA

Adverse events

Common (≥1%)

drowsiness · dry mouth · dizziness · blurred vision · constipation

Rare but serious

rhabdomyolysis · severe anticholinergic toxicity · seizures · agranulocytosis

Pregnancy and lactation

FDA category: B

Contraindicated for the insomnia indication per the European SPC. However, it is considered safe and is first-line therapy (in combination with pyridoxine) for nausea and vomiting of pregnancy (US FDA Category A for the combination).