Dimenhydrinate

ATC code

A04AD05

Therapeutic class

Antiemetic and H1 Antihistamine · First-generation H1 antihistamine

Forms

oral tablet, oral syrup

Brand names

Motion Sickness Relief (US) · Dramamine (US) · Nausicalm (FR) · Biodramina (ES)

Overall confidence

high

Regulatory sources consulted

openfda-label-b9559b5b-f577-4930-ac13-ceb79a7a9c05
ANSM RCP for NAUSICALM (CIS: 69806008)
PubMed PMID:36250781 ↗
PubMed PMID:39976040 ↗
General clinical pharmacology knowledge
OpenFDA · A04AD05
ANSM BDPM · CIS 69806008 ↗
RxNorm rxcui 3444 ↗

Approved indications

Prevention and treatment of symptoms associated with motion sickness, such as nausea, vomiting, and/or dizziness.
Short-term symptomatic treatment of nausea and vomiting not accompanied by fever.

Contraindications

Absolute

Hypersensitivity to dimenhydrinate or other antihistamines.
Risk of angle-closure glaucoma.
Risk of urinary retention related to urethroprostatic disorders.

Relative

Children under 2 years of age (unless directed by a doctor).

Clinical warnings

Major warning · May cause marked drowsiness. Alcohol, sedatives, and tranquilizers may increase this effect. Use caution when driving a motor vehicle or operating machinery. — FDA
Use with caution in patients with bronchial asthma, chronic breathing problems (emphysema, chronic bronchitis), or difficulty in urination due to an enlarged prostate gland. — FDA
Cases of abuse and dependence have been reported, mainly in adolescents and young adults for recreational purposes. — ANSM SPC

Drug interactions

HighAlcoholV03AB16
Mechanism: Potentiation of the sedative effect of the H1 antihistamine. Impaired alertness can make driving and using machinery dangerous.
Recommendation: Avoid consuming alcoholic beverages and medications containing alcohol during treatment.
ANSM SPC
HighCNS depressants (benzodiazepines, opioids, barbiturates)
Mechanism: Increased central nervous system depression.
Recommendation: Use with caution and monitor for increased sedation and respiratory depression.
ANSM SPC
ModerateAtropinic substances (tricyclic antidepressants, antiparkinsonian drugs)
Mechanism: Addition of atropinic adverse effects such as urinary retention, constipation, and dry mouth.
Recommendation: Monitor for the appearance or worsening of anticholinergic effects.
ANSM SPC

Adverse events

Common (≥1%)

drowsiness · sedation · dry mouth · dizziness · blurred vision · accommodation disorders

Rare but serious

hallucinations · mental confusion · seizures · agranulocytosis · hemolytic anemia · anaphylaxis · extrapyramidal symptoms (in children)

Pregnancy and lactation

Pregnancy: Use only if necessary. In the 3rd trimester, limit to occasional use. If used at the end of pregnancy, monitor the newborn's neurological and digestive functions. Lactation: Not recommended for use due to passage into breast milk and its sedative and atropinic properties.

Recent literature (PubMed)

Antihistamines for motion sickness.
Karrim N, et al. · Cochrane Database Syst Rev · 2022 · Relevance 5/5
Revisión sistemática Cochrane que evaluó la efectividad de los antihistamínicos para la prevención y el tratamiento de la cinetosis. Se incluyeron nueve ECA con 658 participantes. Los resultados sobre la eficacia fueron conflictivos, lo que subraya la necesidad de más investigación de alta calidad, aunque los antihistamínicos se han utilizado durante décadas para esta indicación.
Over-the-counter Psychosis: A Systematic Review of the Misuse of Antihistamines, Cough Medicines, and Decongestants and the Risk of Developing Psychosis.
Mosca A, et al. · Curr Neuropharmacol · 2025 · Relevance 4/5
Revisión sistemática sobre el mal uso de medicamentos de venta libre, incluido el dimenhidrinato. El análisis de 46 estudios encontró que el abuso de antihistamínicos puede inducir síntomas psicóticos agudos, como paranoia y alucinaciones. El estudio destaca la necesidad de una mayor concienciación e intervenciones específicas para abordar el mal uso de estos fármacos.