Trazodone

Evidence Level: L2

Predicted Indications: 9

Trazodone

Pharmacist Assessment Report

Trazodone: Obsessive-compulsive disorder

One-Sentence Summary

Trazodone is an antidepressant originally used for depression (unipolar, endogenous and major depressive disorder) and anxiety disorders. The TxGNN model predicts it may be effective for Obsessive-Compulsive Disorder (OCD), with no registered clinical trials but 21 publications (including 1 double-blind placebo-controlled RCT, several case series and open-label studies, and reviews) currently supporting this direction.

Quick Overview

Item	Content
Original Indication	Not recorded in the local data
Predicted New Indication	Obsessive-compulsive disorder
TxGNN Prediction Score	0.9995
Evidence Level	L2
India Market Status	Listed in a compiled Indian medicine price dataset (at least 20) – CDSCO approval status is not included in this data
Number of Listed Products	at least 20
Recommended Decision	Proceed with Guardrails

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available from the original drug record. Based on general pharmacology and the published literature, trazodone acts on the serotonin system: it antagonises 5-HT2A receptors, weakly inhibits serotonin reuptake, and has an active metabolite, mCPP.

Serotonergic modulation is the therapeutic backbone of OCD treatment, where serotonin reuptake inhibitors such as clomipramine, fluoxetine and fluvoxamine are the established agents. Depression and OCD often occur together, and trazodone is already used in depression and anxiety, so a link is biologically plausible.

The evidence is mixed. Published reports describe use in clomipramine-resistant OCD, where three of nine patients responded well, and a PET study linked response to changes in caudate glucose metabolism. However, a pilot study combining trazodone with tryptophan found only marginal benefit and poor tolerability. This link rests on literature and general pharmacology, not on a confirmed mechanism of action.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
1629380	1992	RCT	J Clin Psychopharmacol	Double-blind, placebo-controlled study of trazodone in OCD patients, designed to test its anti-obsessional efficacy in a controlled setting
26088119	2015	Review	Curr Pharm Des	Reviews off-label trazodone use, including OCD, with evidence, benefits and risks
27744763	2017	Review	Postgrad Med	Reviews trazodone’s mechanism, dosing and adverse effects across psychiatric and medical conditions
2119885	1990	Case series / open-label	Clin Neuropharmacol	Nine clomipramine-resistant OCD patients: mild overall improvement, three marked responders whose symptoms returned on withdrawal
3501130	1987	Open-label / mechanistic	Psychopathology	Treatment response correlated with shifts in caudate glucose metabolism on PET
3571943	1986	Open pilot	Int Clin Psychopharmacol	Trazodone plus tryptophan in 11 patients: marginal benefit, poorly tolerated by several
8434675	1993	Case series	Am J Psychiatry	Trazodone in OCD and trichotillomania
4009160	1985	Case report	J Nerv Ment Dis	Two severe OCD patients with depression, previously unresponsive to many antidepressants, improved on trazodone
6703152	1984	Case report	Am J Psychiatry	Early report of trazodone in OCD
2589561	1989	Report	Am J Psychiatry	Trazodone-fluoxetine combination for OCD

Notes: The only controlled trial (1992) is old and its outcome is not given in the data compiled for this report, so the result needs to be verified from the full paper. Most of the remaining evidence is case-level or open-label.

India Market Information

Trazodone is marketed in India with 20 valid single-ingredient registrations, all oral tablets. The registration records contain no approved-indication text. Main registrations:

Authorization Number	Product Name	Dosage Form	Approved Indication
215832	Trazonil 100 Tablet (Intas Pharmaceuticals Ltd)	Strip of 10 tablets	Not stated in record
215401	Trazonil 25 Tablet (Intas Pharmaceuticals Ltd)	Strip of 10 tablets	Not stated in record
217748	Trazalon 25mg Tablet (Sun Pharmaceutical Industries Ltd)	Strip of 10 tablets	Not stated in record
218099	Tazodac 50mg Tablet (Zydus Cadila)	Strip of 10 tablets	Not stated in record
221733	Trazodep 25mg Tablet (Torrent Pharmaceuticals Ltd)	Strip of 10 tablets	Not stated in record

Safety Considerations

Contraindications / cautions from the knowledge graph (not label text): multiple system atrophy, postural orthostatic tachycardia syndrome, orthostatic hypotension, long QT syndrome (including familial), torsades de pointes, potassium deficiency, benign prostatic hyperplasia, blood coagulation disorders, heart and cardiovascular disease, priapism, and inappropriate ADH secretion (including nephrogenic).
Drug Interactions: 258 interactions were identified. Major-level examples include bupropion, lorcaserin, dolasetron, palonosetron, cisapride, fenfluramine and dexfenfluramine. These largely reflect serotonergic or QT-prolonging combinations. Moderate-level examples include famotidine, loperamide, aprepitant, morphine, clarithromycin and dronabinol.
Literature signals: A 2022 case report described raised amisulpride serum levels when trazodone was combined with pregabalin. A 1983 report described myalgia associated with trazodone.

Please refer to the package insert for label warnings, as these were not available in the data compiled for this report.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: Trazodone has a plausible serotonergic rationale, a very high TxGNN score, and a placebo-controlled RCT plus open-label data in OCD. However, the evidence is old, small and mixed, there are no registered trials, and trazodone is not an established first-line OCD agent. It is best treated as a research question, for example as an adjunct in treatment-resistant cases, not as a ready-to-adopt indication.

To proceed, the following is needed:

Full-text review of the 1992 RCT to confirm its outcome, dose and sample size
Modern, adequately powered controlled trials in OCD, especially adjunctive use in SRI-resistant patients
Mechanism of action data from DrugBank
Indian package insert warnings and contraindications
A safety plan covering QT prolongation, orthostatic hypotension, priapism, and serotonergic and QT-prolonging drug interactions

Other Predicted Indications (for reference)

Predicted Indication	TxGNN Score	Evidence Level	Decision
Agoraphobia	0.9981	L3	Research question (older panic disorder studies; trazodone appeared less effective than imipramine and alprazolam)
Phobic disorder	0.9945	L5	Research question (overlaps with agoraphobia evidence)
Histrionic personality disorder	0.9992	L5	Hold (only a 1975 hysteria report)
Paranoid personality disorder	0.9992	L5	Hold (only a drug-interaction case report)
Schizotypal personality disorder	0.9992	L5	Hold (prediction only)
Schizoid personality disorder	0.9992	L5	Hold (prediction only)
Benign paroxysmal torticollis of infancy	0.9983	L5	Hold (prediction only; paediatric safety unsupported)
Ohdo syndrome and variants	0.9928	L5	Hold (prediction only; no plausible link)

Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.