Dothiepin / dosulepin

Clinical contraindication: None listed; No clinical contraindication identified.
Best available evidence: Mechanism only
Half-life: ~50 h; Approximate, in adults. Detail in 01.

Named in state rules?

CONot named

ORNot named

NMPending

Cite asPsilodex: dothiepin-dosulepin · v2026.10.02

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

01 Interaction with psilocybin

Direction unclear; serotonergic; QT, arrhythmia and seizure-threshold risk.

Human data with psilocybin: None known: no published human data with psilocybin
Half-life: ~50 h for dosulepin and metabolites (UK SmPC) (UK SmPC, checked 2026-09-30)

Evidence types on this record

ThMechanism only (theoretical)

3 listed · counted on reports

QT-prolonging: Lengthens the QT interval on an ECG, a measure of the heart’s electrical recovery between beats. A long QT raises the risk of a dangerous heart rhythm, more so with other QT-prolonging drugs or low potassium or magnesium. Sources [2]
Lowers seizure threshold or carries seizure risk: Makes a seizure more likely, or has been linked to seizures. Sources [1]
Serotonergic: Increases serotonin activity, for example by blocking its reuptake or releasing it. Psilocybin acts on serotonin receptors, so effects can add together. With antidepressant use, the psilocybin response can be weaker. Sources [4]

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 2026-09-30

None linked

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

Non-US product information
Bazire S. Psychotropic Drug Directory 2018. Lloyd-Reinhold Publications, 2018., p. 258
NIMH Psychoactive Drug Screening Program (PDSP) Ki Database, University of North Carolina. Roth BL et al. (per-entry query link; primary references in note) — 5-HT2A Ki 152 nM rat (Sanchez 1999); flag not applied
Preston CL (ed). Stockley’s Drug Interactions, 11th ed. Pharmaceutical Press, 2016., p. 1484 — class: tricyclic antidepressants in Table 35.3, drugs associated with serotonin syndrome