Can You Take Citalopram with Diazepam?

Severity assessment

Moderate. Concomitant use can lead to increased central nervous system (CNS) depression, resulting in enhanced sedation, dizziness, and impaired psychomotor function.

Mechanism (plain English)

Citalopram, a selective serotonin reuptake inhibitor (SSRI), works by increasing the levels of serotonin in the brain, which helps regulate mood. Diazepam, a benzodiazepine, enhances the effect of gamma-aminobutyric acid (GABA), a neurotransmitter that calms brain activity. When taken together, both medications contribute to a general slowing down of brain function, leading to additive sedative effects. This can result in increased drowsiness, dizziness, and difficulty with coordination and concentration.

Evidence level

Regulator-flagged. The interaction is highlighted in product information from regulatory bodies and supported by clinical guidelines.

Top regulator advisories (cite verbatim or close paraphrase)

• TGA (Australia): No specific pair-specific public advisory found. However, the Product Information for citalopram generally advises caution with other CNS medications. The Valium (diazepam) Product Information also warns about concomitant use with other CNS depressants.
• MHRA / NICE (UK): The British National Formulary (BNF) states that both citalopram and diazepam have effects on the CNS and can cause sedation, which might affect the ability to perform skilled tasks.
• FDA (US): The FDA label for citalopram (Celexa) advises caution when citalopram is taken in combination with other centrally acting drugs due to its primary CNS effects. The FDA label for diazepam also warns against the simultaneous ingestion of alcohol and other CNS-depressant drugs during diazepam therapy.
• EMA (Europe): No specific pair-specific advisory found, but general warnings regarding CNS depressants apply.

Clinical risk factors that elevate the danger

• Age: Elderly patients may be more susceptible to the sedative effects and impaired psychomotor function, increasing the risk of falls and cognitive impairment.
• Hepatic/Renal Impairment: Patients with compromised liver or kidney function may have reduced clearance of one or both drugs, leading to higher plasma concentrations and increased risk of adverse effects.
• Concomitant CNS Depressants: Concurrent use of other medications that depress the central nervous system (e.g., opioids, alcohol, other sedatives) will further enhance the sedative effects.
• Higher Doses: Increased doses of either citalopram or diazepam will heighten the risk and severity of CNS depression.

What a patient should be told

• Risk of increased drowsiness: You might feel more sleepy, dizzy, or have trouble concentrating. This can make activities like driving or operating machinery dangerous.
• Do not stop suddenly: Do not stop taking either medication abruptly without talking to your doctor or pharmacist, as this can lead to withdrawal symptoms or worsening of your condition.
• Watch for warning signs: Be aware of excessive drowsiness, extreme dizziness, confusion, slow or shallow breathing, or difficulty waking up. If you experience these, seek medical attention.
• Discuss alternatives: Talk to your doctor or pharmacist about all medications you are taking, including over-the-counter drugs and herbal supplements, to ensure this combination is right for you. Safer alternatives or dose adjustments might be necessary.
• Urgent care triggers: If you experience severe difficulty breathing, unresponsiveness, or extreme confusion, seek urgent medical care immediately.

Top 3 sources (with full citation)

1. Drugs.com. Citalopram and Diazepam Drug Interactions. Available at: https://www.drugs.com/drug-interactions/citalopram-with-diazepam-679-0-862-0.html
2. British National Formulary (BNF) via NICE. Diazepam: Interactions. Available at: https://bnf.nice.org.uk/interactions/diazepam/
3. Lundbeck Canada Inc. CELEXA® (citalopram hydrobromide) Product Monograph. Date of Authorization: 2025-12-23. Available at: https://pdf.hres.ca/dpd_pm/00063999.PDF

Notes for the reviewing pharmacist

Co-prescription of SSRIs and benzodiazepines is common, particularly in the initial stages of antidepressant therapy to manage anxiety or agitation. While the interaction is primarily pharmacodynamic, leading to additive CNS depression, pharmacokinetic interactions are generally not considered significant for this specific pair. Close monitoring for excessive sedation, respiratory depression, and psychomotor impairment is crucial, especially in vulnerable populations such as the elderly or those with hepatic/renal compromise. Patient education should emphasize the risks of impaired alertness and the importance of not discontinuing medication abruptly. Consider lower starting doses and slower titration when co-administering. The potential for misuse and dependence with diazepam also warrants careful consideration, particularly in patients with a history of substance abuse. The absence of specific regulator advisories for the exact pair in some jurisdictions necessitates reliance on general warnings for CNS depressants and clinical judgment.

Source metadata JSON

{
  "pair": "citalopram + diazepam",
  "severity": "Moderate",
  "evidence_level": "Regulator-flagged",
  "source_urls": "https://www.drugs.com/drug-interactions/citalopram-with-diazepam-679-0-862-0.html;https://bnf.nice.org.uk/interactions/diazepam/;https://pdf.hres.ca/dpd_pm/00063999.PDF"
}