According to the WHO, more than 700,000 people die per year due to suicide. 90% of individuals who die by suicide have a history of psychiatric illnesses. Suicide is a complex phenomenon involving several systems and neurobiological pathways. Neurobiology of suicide are multi-mechanisms including neuroinflammation, serotonin system, reduction of brain-derived neurotrophic factor, HPA axis hyperactivity. To date, no medications have proven efficacious for treating acute suicidal crises.

Pharmacotherapy for treatment and prevent of suicide rely mostly on the treatment of primary psychiatric disorders and manage factors that associated with suicide. Factor that associated with suicide including sleep disturbance, substances, nonadherence of psychotropic medications and other factors (comorbid physical illnesses, psychosocial features, cognitive impairment). Medication for suicide reduction based-on evidence including antidepressant in major depressive disorders (MDD), clozapine in schizophrenia, lithium in mood disorders and ketamine or intranasal esketamine in mood disorders. Clozapine is approved by US FDA for reduced the risk of suicide in schizophrenia or schizoaffective disorder. Anti-suicidal effects of CLZ seem to be independent of antipsychotic effect. Effective dose of CLZ for suicide reduction (mean dose 275 mg/d) is lower than for treatment-resistant schizophrenia (300-600 mg/d). Discontinuation of CLZ is associated with increase suicidality. Lithium has direct anti-suicidal effect (independent of mood stabilizing effect) and evidence-based found reduced suicide in patients with mood disorders (both MDD and bipolar disorders). Therapeutic level of lithium is approximately 0.5-1 mEq/L. Discontinuation of lithium increased risk of suicide. Therefore, lithium should be consider treating patients with bipolar disorder or treatment-resistant depression with high risk suicide. Intranasal esketamine was approved in adult treatment-resistant depression and adult MDD with acute suicidal ideation / behavior. Intranasal esketamine was rapid onset and significantly reduced depressive symptoms more than placebo within 2-4 hours. Safety monitoring of intranasal esketamine at least 2 hours post-dose under medical supervision is essential because of its dissociative, sedative, and cardiovascular effects, as well as risk for abuse. For serotonergic antidepressants in MDD patients with suicidal ideation, evidence-based found serotonergic antidepressants especially SSRIs and suicidal reduction effect depend-on age. SSRIs found reduced suicide in adult and elderly patients with MDD. However, in children and adolescent with MDD, SSRIs may increase or no change the risk of suicide when compare with placebo.

Thanompong Sathienluckana, PharmD, Board Certified Pharmacotherapy (BCP), is a clinical pharmacy lecturer in the Faculty of Pharmacy, Siam University. Current position is Associate Dean for Academic Services at Faculty of Pharmacy, Siam University and Academic chair of Pharmacotherapy council of Thailand. His area of interest is the pharmaceutical care in neurologic and psychiatric disorders. He also practice with multidisciplinary team at the Somdet Chaopraya Institute of Psychiatry, Bangkok, Thailand. He graduated Pharm.D. degree at faculty of pharmacy, Srinakharinwirot University, Thailand in 2009. Then,he graduated pharmacy residency program at The College of Pharmacotherapy of Thailand and received Board Certified Pharmacotherapy (BCP).