en psychiatry psychiatry case report case report <pre> <span style="font-size: 14px;"><span style="font-family: times new roman;"><span style="color: rgb(0, 0, 255);"><strong><em>Background</em></strong><em>:</em></span> Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are prescribed widely for the treatment of depression, anxiety disorders and other psychiatric disorders. Although antidepressants are considered as a safety drug category but unexpected cardiovascular events have been reported as the most serious complications. The aim of this study was to introduce a case presentation on bradycardia due to the drug interference of venlafaxine and cyclosporine. <span style="color: rgb(0, 0, 255);"><strong><em>Case presentation:</em></strong></span> The patient was a 38-year old woman diagnosed with systemic lupus erythematosus 5 years ago, who was admitted to a general educational hospital in northern Iran due to intensified rheumatologic symptoms and complaining about abdominal pain. Cyclosporine tab were administered to the patient, 50 mg twice daily. Two weeks after the administration of cyclosporine, the level of blood cyclosporine was checked. The patient became bradycardic after starting a single dose of venlafaxine (heart rate 52 ppm). Cardiac assessment showed no reason for bradycardia and it subsided after a drop of venlafaxine. <span style="color: rgb(0, 0, 255);"><strong><em>Conclusion</em></strong><em>:</em></span> As a result of the potential adverse drug interactions between cyclosporine and antidepressants such as venlafaxine, physicians should be aware of the possibility of bradycardia in the simultaneous prescription of these drugs in cases. </span></span> </pre> Bradycardia, Venlafaxine, Cyclosporine, Serotonin-Norepinephrine reuptake inhibitors, Selective serotonin reuptake inhibitors. 463 467 http://caspjim.com/browse.php?a_code=A-10-846-5&slc_lang=en&sid=1 Marzieh Azizi marziehazizi70@gmail.com 100319475328460018870 100319475328460018870 No Sexual and Reproductive Health Research Center, Nasibeh Nursing and Midwifery Faculty, Mazandaran University of Medical Sciences, Sari, Iran Forouzan Elyasi Forouzan. El @gmail.com 100319475328460018871 100319475328460018871 Yes Department of Psychiatry, Psychiatry and Behavioral Sciences Research Center and addiction Institute, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran fatemeh Niksolat Roodposhti Fniksolat@yahoo.com 100319475328460018872 100319475328460018872 No Department of Internal Medicine, Orthopedic Research Center, Mazandaran University of Medical Sciences, Sari, Iran