Invega Sustenna 75mg Injection contains paliperidone, an atypical antipsychotic agent used primarily for the treatment of schizophrenia and schizoaffective disorder. Administered via intramuscular injection, this long-acting formulation provides sustained therapeutic plasma concentrations, facilitating once-monthly dosing and improving patient adherence. Paliperidone exerts its pharmacological effects by antagonizing dopamine D2 and serotonin 5-HT2A receptors, which helps to restore the neurotransmitter balance implicated in psychotic symptoms. Invega Sustenna is indicated for the maintenance treatment of schizophrenia in adults and adolescents aged 12 years and older, as well as for schizoaffective disorder as monotherapy or adjunctive therapy with mood stabilizers or antidepressants. The 75mg dose is typically initiated following a recommended titration schedule to achieve optimal plasma levels while minimizing adverse effects. Common side effects may include extrapyramidal symptoms, weight gain, sedation, and increased prolactin levels. Caution is advised in patients with a history of cardiovascular disease, seizures, or renal impairment. Regular monitoring of metabolic parameters and neurological status is recommended during treatment. Invega Sustenna 75mg Injection offers a convenient and effective option for long-term management of psychotic disorders, enhancing compliance and clinical outcomes.