4-HO-EPT

valvular heart disease, coronary artery disease, heart failure, arrhythmia

Cardiovascular disease is a relative contraindication. 4-HO-EPT's 5-HT₂B binding (Ki = 62 nM, highest-affinity target) raises theoretical concern for cardiac valvulopathy, particularly in individuals with pre-existing valvular disease. Additional H₁ and α₂A binding may produce mild hemodynamic perturbation. No cardiovascular monitoring data exist for 4-HO-EPT.

hallucinogen persisting perception disorder

Personal history of hallucinogen persisting perception disorder (HPPD) is a relative contraindication. As a 5-HT₂A agonist, 4-HO-EPT carries theoretical risk of HPPD exacerbation (Litjens et al. 2014). No 4-HO-EPT-specific HPPD cases have been reported.

schizophrenia, schizoaffective disorder, family history of psychotic disorders

Personal or family history of psychotic disorders is an absolute contraindication. 5-HT₂A agonist psychedelics can trigger acute psychosis in vulnerable individuals, and 4-HO-EPT's confirmed 5-HT₂A agonism (Ki = 546 nM) carries this class-level risk.

bipolar I disorder, bipolar II disorder

Bipolar disorder is a relative contraindication. Risk of manic episode precipitation exists by class inference from serotonergic psychedelics, though no 4-HO-EPT-specific cases have been reported.

pregnancy, breastfeeding

Pregnancy and breastfeeding are relative contraindications due to complete absence of reproductive and developmental safety data for 4-HO-EPT or structurally related 4-hydroxytryptamines in pregnancy.

current lithium therapy

Current lithium use is an absolute contraindication. Published case reports and class-level evidence document seizures and severe adverse reactions when lithium is combined with serotonergic psychedelics.

current MAOI therapy, moclobemide, phenelzine, tranylcypromine, selegiline, ayahuasca

Current MAOI use is an absolute contraindication. Co-administration would be expected to produce uncontrolled potentiation of duration and intensity plus clinically significant serotonin toxicity risk. This interaction is not currently in the substance database but is strongly supported by class pharmacology (Malcolm & Thomas 2022).

current tramadol use

Current tramadol use is an absolute contraindication. Tramadol's dual serotonergic mechanism (reuptake inhibition + release stimulation) combined with 4-HO-EPT's multi-target serotonin receptor agonism creates dangerous serotonin toxicity risk (Park et al. 2014).

current SSRI therapy, current SNRI therapy

Current SSRI or SNRI use is a relative contraindication. The interaction is bidirectional — reduced psychedelic efficacy plus theoretical serotonin toxicity risk. Neither effect has been characterized for 4-HO-EPT specifically (Malcolm & Thomas 2022).