Dimenhydrinate

An antihistamine (a salt of diphenhydramine), FDA-approved over the counter and by injection to prevent and treat nausea, vomiting and dizziness of motion sickness.

psilodex.org/m/dimenhydrinate · data v2026.10.04

Clinical contraindication: None listed; No clinical contraindication identified.
Psilocybin evidence: No psilocybin data
Half-life: Not stated in label or references

Named in state rules?

Not namedColorado

Not namedOregon

PendingNew Mexico

Cite asPsilodex, “Dimenhydrinate”, v2026.10.04. psilodex.org/m/dimenhydrinate

Clinical data and state rules are separate facts. Both are shown; neither is a decision.

What it is used for

FDA status

FDA-approved

Over-the-counter tablets are sold under FDA's OTC antiemetic monograph (M009); dimenhydrinate injection (Rx) is FDA-approved.

FDA-approved for

Nausea, vomiting and dizziness of motion sickness (prevention and treatment)
Vertigo of motion sickness (injection)

Sources [1][2]

01 Interaction with psilocybin

Its drowsiness and anticholinergic effects may add to psilocybin's effects; it is a salt form of diphenhydramine.

Detail Diphenhydramine salt; no psilocybin data. Labels note marked drowsiness, dizziness and anticholinergic effects, which may in theory add to psilocybin's altered state and confusion.

Human data with psilocybin: None known: no published human data with psilocybin

Evidence types on this record

No psilocybin dataNo psilocybin data; record based on general references (product label, reference works, reviews)

02 Pharmacology relevant to psilocybin

2 listed · counted on reports

Anticholinergic: Blocks acetylcholine. Can cause a fast heart rate, dry mouth, reduced sweating and heat intolerance, and confusion, more so at high doses or in combination. Sources [2]
Sedating or CNS depressant: Slows the central nervous system: drowsiness, slower reactions and impaired coordination, and slowed breathing at high doses. Effects add with other sedating substances. Sources [1][3]

03 State rules

Plain-language summary · official text governs

CO4 CCR 755-1

Not named

No provision names this medication or its class.

Colorado · checked 2026-09-30

OROAR 333-333

Not named

No provision names this medication or its class.

Oregon · checked 2026-09-30

NM7.35.3 NMAC (proposed)

Pending

New Mexico's clinical rules (proposed 7.35.3 NMAC) are not final. No provision naming this medication has been found.

New Mexico · checked 2026-10-02

04 Conditions to ask about

None linked

No condition named in state rules is linked to this medication.

05 Sources

DRAMAMINE ORIGINAL FORMULA (dimenhydrinate) tablet, Medtech Products, rev 10/2025 · FDA label (DailyMed) — cns_depressant: Drug Facts – When using this product "marked drowsiness may occur"
DIMENHYDRINATE injection, solution (Fresenius Kabi), rev 01/2025 · FDA label (DailyMed) — Rx injection; states dimenhydrinate is the 8-chlorotheophylline salt of diphenhydramine. | anticholinergic: PRECAUTIONS "patients having conditions which might be aggravated by anticholinergic therapy (i.e., prostatic hypertrophy, stenosing peptic ulcer, pyloroduodenal obstruction, bladder neck obstruction, narrow-angle glaucoma"
DRIMINATE (dimenhydrinate) tablet, rev 06/2026 · FDA label (DailyMed)
GRAVOL (dimenhydrinate) tablet, coated, rev 03/2022 · FDA label (DailyMed)
DailyMed search: dimenhydrinate · FDA label (DailyMed) — Lists DRAMAMINE (dimenhydrinate) and Gravol products with dimenhydrinate as active ingredient.

Record history

v2026.10.02First published.
2026-10-03Last reviewed against its sources.

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