Citalopram
| Evidence Level: L2 | Predicted Indications: 5 |
Table of Contents
Citalopram: Obsessive-compulsive disorder
One-Sentence Summary
Citalopram is a selective serotonin reuptake inhibitor (SSRI) marketed in Canada under multiple licences. The TxGNN model predicts it may be effective for obsessive-compulsive disorder, supported by 4 registered clinical trials (only indirectly related to citalopram) and 16 publications, including several citalopram-specific small studies. The evidence level is L2.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not recorded in the local data |
| Predicted New Indication | Obsessive-compulsive disorder |
| TxGNN Prediction Score | 0.9974 |
| Evidence Level | L2 |
| Canada Market Status | Marketed (marketed DINs on record: at least 20) |
| Number of DINs | at least 20 |
| Recommended Decision | Proceed with Guardrails |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data for citalopram is not available in the data compiled for this report. Based on general pharmacological knowledge, citalopram is a highly selective serotonin reuptake inhibitor. Serotonergic dysregulation in cortico-striato-thalamo-cortical circuits is central to the pathophysiology of obsessive-compulsive disorder (OCD), and SSRIs are first-line pharmacotherapy for it.
Depression and anxiety, which citalopram is used for, share this serotonergic mechanism and frequently co-occur with OCD. This makes the prediction mechanistically plausible. The supporting evidence is small: one randomized single-blind comparison of three SSRIs, plus several open-label studies. No placebo-controlled Phase 3 trial of citalopram in OCD was found in the data.
Clinical Trial Evidence
None of the registered trials tests citalopram specifically; they address SSRIs or related treatments in OCD more broadly.
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT02022709 | Phase 4 | Completed | 78 | Exposure and response prevention, SSRIs, and their combination in OCD; also looks for predictors of response in a Chinese population |
| NCT00074815 | Phase 3 | Completed | 124 | Cognitive behavioural therapy added to serotonin reuptake inhibitor treatment in children with OCD who partially responded |
| NCT00680602 | Phase 4 | Completed | 158 | Group cognitive behavioural therapy versus fluoxetine in OCD; class-level context only |
| NCT02285699 | N/A | Completed | 43 | Gut microbiota in OCD versus healthy controls, before and after 12 weeks of SSRI treatment; not an efficacy study |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 9241005 | 1997 | Single-blind comparison | J Clin Psychopharmacol | Compared the antiobsessional efficacy of fluvoxamine, paroxetine and citalopram in 30 patients with OCD |
| 10572334 | 1999 | Randomized open-label trial | Eur Psychiatry | Citalopram alone versus citalopram plus clomipramine in 16 patients with treatment-resistant OCD |
| 9395151 | 1997 | Open pilot study | Acta Psychiatr Scand | 24-week open pilot study of citalopram in OCD |
| 12839522 | 2003 | Open-label study | Psychiatry Clin Neurosci | 8-week open-label study of citalopram (mean 24 mg/day) in 15 children and adolescents with OCD |
| 9466233 | 1997 | Open trial | J Child Adolesc Psychopharmacol | Citalopram 10–40 mg daily in 23 children and adolescents; Y-BOCS/CY-BOCS scores fell significantly after 10 weeks |
| 15089116 | 2004 | Cohort | CNS Drugs | Preliminary study of the relationship between citalopram concentrations and clinical response in OCD |
| 10471169 | 1999 | Review | Int Clin Psychopharmacol | Review of citalopram for OCD, covering the link between serotonin reuptake inhibitors and OCD |
| 20712565 | 2010 | Review | Curr Med Chem | Past, present and future drugs for OCD, with SSRIs central to treatment |
Canada Market Information
Citalopram is marketed in Canada, with all 20 licences currently valid. The records may be partial. Main authorizations:
| DIN | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| 02239608 | CELEXA 40 MG | Not recorded | Not recorded |
| 02312336 | TEVA-CITALOPRAM | Not recorded | Not recorded |
| 02313405 | JAMP-CITALOPRAM | Not recorded | Not recorded |
| 02248010 | PMS-CITALOPRAM | Not recorded | Not recorded |
| 02303256 | RIVA-CITALOPRAM | Not recorded | Not recorded |
Safety Considerations
- Drug Interactions: 100 interacting drugs were identified. Major-level interactions include bupropion, omeprazole, cimetidine, cisapride, clarithromycin, lorcaserin, dexfenfluramine, diethylpropion and dolasetron. Moderate-level examples include famotidine, loperamide, morphine and acetylsalicylic acid.
- Conditions of concern: Citalopram is recorded as contraindicated or to be used with great caution in long QT syndrome, torsades de pointes, epilepsy, bipolar disorder, liver disease, heart disease, blood coagulation disorders, potassium deficiency, serotonin syndrome, neuroleptic malignant syndrome and inappropriate ADH secretion.
Please refer to the package insert for full warnings and contraindications.
Conclusion and Next Steps
Decision: Proceed with Guardrails
Rationale: Citalopram is mechanistically plausible for OCD and has a very high TxGNN score (0.9974). Several small citalopram studies, including one single-blind comparison, show a signal (Level L2). However, no placebo-controlled Phase 3 trial exists, and the registered trials do not test citalopram specifically.
To proceed, the following is needed:
- A placebo-controlled randomized trial of citalopram in OCD
- Package insert warnings and contraindications from Health Canada
- Detailed mechanism-of-action data
- A cardiac (QT) monitoring plan and a review of interacting medicines, given the QT-related conditions and major interactions listed above
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.