Comparing the medication costs of treating patients with schizophrenia who use cannabis with those who do not

Background: Cannabis use is more prevalent among people with schizophrenia than in the general population. This usage detrimentally impacts disease prognosis, contributing to escalated admissions, heightened severity of psychotic symptoms, and reduced medication response. The recent decriminalisation of cannabis in South Africa may lead to an upsurge in usage, consequently intensifying the strain on mental healthcare services.Aim: This study aimed to compare the medication costs of patients with schizophrenia depending on cannabis use.Setting: Weskoppies Hospital, Pretoria, South Africa, 2018–2019.Methods: Data pertaining to medication expenses during the 2018–2019 period were acquired from the hospital pharmacy. Data were collected from 114 patient records to form two equal cohorts: one exposed to cannabis and the other non-exposed, as indicated by urine drug screens or admission of cannabis use. Medications prescribed from admission to time of being ready for discharge were recorded and corresponding costs were calculated.Results: Patients who were exposed to cannabis had higher medication costs (R 516.47) than patients who were non-exposed (R 328.69) (p = 0.0519), over the whole admission period.Conclusion: Cannabis exposure escalates the financial burden of treating schizophrenia at Weskoppies Hospital. This might be attributed to failure of cost-effective, first-line medications prompting the prescription of costlier, second-line alternatives or higher prescribed dosages.Contribution: This study contributes to findings that it is more expensive to treat patients with schizophrenia who have relapsed, if they are using cannabis. This finding has future cost implications when budgeting for pharmacotherapeutic treatment.