Doxylamine

Compound CodeKAT-SED-02
Pharmacological TagSedative antihistamine / Anticholinergic / Hypnotic
Structural ClassEthanolamine H1 receptor inreverse agonist
Mechanism H1 receptor inverse agonist Central histamine suppression Muscarinic receptor blockade (anticholinergic load) Mild serotonergic modulation (non-primary)
Functional Role Sleep induction Antiemetic (in combination with Vitamin B1)
Structural Analogues Diphenhydramine Promethazine Carbinoxamine Other first-generation ethanolamines
Onset~30 minutes (oral)
Duration6–10 hours
Affinity Profile High CNS penetration Strong H1 antagonism Moderate muscarinic antagonism Minimal selective receptor precision (dirty drug)
Pharmacokinetics Oral bioavailability: high Peak plasma: 2-3h Half-life: ~10-12h Hepatic metabolism Renal elimination
Secondary effects Somnolence Dry mouth Blurred vision Cognitive slowing Paradoxical excitation
Interpretation Pre-receptor era sedative architecture Histamine shutdown in behavioural control Anticholinergic as therapeutic relevant Legacy molecule still in use on modern insomnia