Pregabalin-induced self-harm behavior
A 21-year-old male patient weighing 52 kg who was diagnosed with chronic low back pain was prescribed capsule pregabalin 75 mg, o.d., at bed time for 2 weeks and local treatment in the form of diclofenac gel and hot fermentation with back strengthening exercises. The patient had no history of smoking, alcohol consumption, or any substance abuse. There was no other associated pathology or history of any concurrent drug intake. He had no personal history or family history of any previous mental/psychiatric disorders. The patient was referred to the adverse drug reaction monitoring (ADRM) centre after 2 months of treatment with complaint of recent change in behavior manifesting as compulsion to take pregabalin at night in spite of the presence or absence of pain and an attempt of self-harm in the form of self-inflicted multiple cuts on the forearm []. Recent disinterest in work, family, friends, clothing, and food was also reported by the family. There was no history of weight change, anxiety, or insomniaor any conflict with family, friends or at work place. Clinical examination revealed that there was no rheumatological or neurological problem. Physiatrist evaluation revealed that Hamilton Rating Scale for Depression (HAM-D) score was 15 suggesting mild depression at the time of examination.\nLaboratory investigations such as complete blood count, hemoglobin, complete blood count, routine urine and stool examination, blood sugar, liver function test, renal function test, lipid profile and electrocardiogram, and X-ray lumber sacral spine were normal.\nThe patient was advised to stop the drug, when the cause of the recent behavioral change could not be ascertained, on suspicion that pregabalin was the causal drug. De-challenge of drug did not cause any withdrawal symptoms. Depressive symptoms disappeared on the eighth day after de-challenge. However, after being advise by psychiatrist, the patient was started olanzapine (2.5 mg, o.d.) in view of potential serious consequences of the ADR. Further re-challenge was not done in the interest of the patient fearing reappearance of ADR and due toethical constraints. The appearance of self-harm behavior in a patient taking pregabalin could not be explained by a concurrent disease, drug, or chemicals. A dechallenge followed by treatment with an antidepressant improved the symptoms.\nThe ADR was ‘Probable’ as assessed by the causality scale with Naranjo (score of six) and the WHO Uppsala Monitoring Centre (UMC) scale. The case was reported to ADRM Centre, Government Medical College, Jammu.