← hubDrugs

Diphenhydramine

Discover related

4 sources

← All substances
🔗 MergedComparePsychonautWikiTripSitPharmacologyDrugCentral

How the databases line up — = agree, partial, differ. In lists, shared items appear in every source and unique ones in only one (matched case-insensitively).

Show:
PsychonautWikiTripSitPharmacologyDrugCentral
Classification
Class / category
Also known as
DPHBenadrylNytolSominexUnisom SleepMeltsZzzQuil
diphenhydraminedphbenadryl
Safety
Addiction potentialproduces dependence with chronic use
Toxicity
fatal at amounts close to or exceeding 2 grams
Dangerous interactions
Dose · Oral
Threshold25 mg
Light100–200 mg100–250 mg
Common200–400 mg200–500 mg
Strong400–700 mg450–700 mg
Heavy700 mg+
Duration
Onset30–90 minutes60–120 minutes
Total3–10 hours6–8 hours
After-effects24 hours1–12 hours
Pharmacology
Receptor activity
Histamine H1 receptorMuscarinic acetylcholine receptor M4Muscarinic acetylcholine receptor M1Muscarinic acetylcholine receptor M5Muscarinic acetylcholine receptor M35-hydroxytryptamine receptor 2AMuscarinic acetylcholine receptor M25-hydroxytryptamine receptor 2C5-hydroxytryptamine receptor 2BSodium-dependent noradrenaline transporterUncheckedHistamine H4 receptorVoltage-gated inwardly rectifying potassium channel KCNH2
HRH1HTR2AHTR2BHTR2CCYP2D6HRH4CHRM1CHRM2CHRM3CHRM4CHRM5KCNH2SCN1ASLC6A3SLC6A2SLC6A4SLC22A2
Half-lifeThe elimination half-life ranges from 2.4-9.3 hours in healthy adults. The terminal elimination half-life is prolonged in liver cirrhosis. The pharmacokinetics and pharmacodynamics of the H1-receptor antagonist diphenhydramine were studied in 21 fasting subjects divided into three age groups: elderly, (mean age 69.4 +/- 4.3 years), young adults, (mean age 31.5 +/- 10.4 years), and children, (mean age 8.9 +/- 1.7 years). All subjects ingested a single dose of diphenhydramine syrup 1.25 mg/kg. ... The mean serum elimination half-life values for diphenhydramine differed significantly in elderly adults, young adults, and children, with values of 13.5 +/- 4.2 hours, 9.2 +/- 2.5 hours, and 5.4 +/- 1.8 hours being found respectively in each age group. ... The terminal elimination half-life of diphenhydramine has not been fully elucidated, but appears to range from 2.4-9.3 hours in healthy adults. The terminal elimination half-life reportedly is prolonged in adults with liver cirrhosis.
Protein bindingSome prescribing information records the protein binding of diphenhydramine as approximately 78% while others have suggested the medication is about 80 to 85% bound to plasma proteins.

Dose at a glance

Each database's primary-route ladder on one shared scale — see where ranges line up or shift.

PsychonautWiki oral
TripSit Oral
0875 mg
LightCommonStrongHeavy

Duration at a glance

Total duration on one shared scale.

PsychonautWiki
3–10 hours
TripSit
6–8 hours

PsychonautWiki summary

Diphenhydramine use is associated with highly uncomfortable and/or dangerous experiences. Deliriants are highly unpredictable and may result in erratic behaviors, self-injury, hospitalization, or death. It should be noted that most individuals do not choose to repeat the experience due to its unpleasant nature.

TripSit summary

An antihistamine which, when taken in smaller doses relieves allergies and insomnia. In larger doses works as a deliriant and can actually keep the user awake. Generally the 'high' of this drug is reported as dysphoric, potentially causing hallucinations indistinguishable from reality.

Fact-sheets from PsychonautWiki. Harm-reduction reference only — not medical advice.