Background. Individuals with Schizophrenia Spectrum Disorders (SSD) often experience significant impairment in educational, occupational, and psychosocial functioning. The clinical benefit of long-acting injectable antipsychotics (LAIs) in the management of patients with SSD is well established. SSD patients who are nonadherent to treatment have lower disease relapse and readmission rates when prescribed a LAI, compared to oral antipsychotics. Despite the reported advantages of LAIs, their prescription rates in clinical settings remain low. This pilot study aimed to determine the pattern of LAI prescription in psychiatric inpatients of a teaching community hospital in Brooklyn, New York. Methods. A retrospective review of the charts of patients discharged from the psychiatric units of the hospital from September 1, 2017, through September 30, 2017, was conducted. Frequencies and proportions for demographic and disease-related characteristics were calculated. Pertinent continuous variables were recoded into categorical variables. Chi-square-tests or Fisher’s exact tests were performed for categorical variables. The one-sample Shapiro-Wilk test (for sample size < 50) was used to check for the normality of distribution of continuous variables. Statistical significance was defined as p ≤ 0.05. Results. Forty-three (70%) of the patients discharged from the inpatient unit during the study period had SSD and were eligible for a LAI. Their ages ranged from 20 to 71 years (mean = 41 years), and more than two-thirds were male. Less than half of the eligible patients (n = 19; 44%) were prescribed a LAI, most of whom were male (n=16; 84%). An association between age group (patients aged 41 years or younger) and LAI use was observed (p < 0.05), while gender, employment status, living arrangement, length of hospital stay, recent hospitalization, and cooccurring substance use disorder were not. Conclusion. LAI prescription rate at the inpatient psychiatric unit of the hospital was marginally higher than those reported in most studies. Age appears to influence LAI use during the study period. Initiatives that increase LAI prescription rate for all eligible patients admitted to inpatient psychiatric unit should be encouraged.

Long-acting injectable (LAI) antipsychotics first introduced in 1960s are useful in the treatment of schizophrenic patients with poor medication adherence due to their maintaining feature of therapeutic plasma level without daily administration. Paliperidone Palmitate is one of such LAI antipsychotic drugs used due to its benefit of maintaining a therapeutic plasma level with four-week interval of injections. We report the case of a 21-year-old male with a history of mental illness that presented with selective mutism, disorganized speech, thought process and behavior, and auditory hallucinations who accidentally received 624 mg Paliperidone Palmitate intramuscularly with no reported side effects after 2 weeks of monitoring and observation. Paliperidone is a D2, 5HT2A receptor antagonist with additional antagonist activity at α-1 and α-2, H-1 receptor sites, and four metabolic pathways identified for its metabolism. Studies have reported adverse effects such as acute dystonia, acute renal failure, and cardiovascular abnormalities with Paliperidone overdose; however there is no reported literature on Paliperidone Palmitate overdose, though there have been reported cases of Paliperidone Palmitate side effects of hypersexuality and angioedema with the standard dose.