Background: Drug–drug interactions (DDIs) occur when two or more drugs are administered concomitantly, changing the pharmacokinetics or pharmacodynamics of a drug’s characteristics. Despite the advances in health technology, DDIs remain a concern to patient safety. This study aimed to (1) assess the knowledge, attitude, and practice of hospital and community pharmacists toward DDIs in Saudi Arabia and (2) examine factors associated with their practice. Methods: A cross-sectional study was conducted using an online self-administered questionnaire targeting hospital and community pharmacists working in Saudi Arabia. The study questionnaire consisted of five sections: demographics, knowledge, attitude, and practice toward DDIs, as well as pharmacy characteristics. Descriptive statistics were used to summarize the characteristics of participants as count and percentage. Chi-square tests were used to examine associations between practice variables and other independent variables. Results: A total of 131 pharmacists participated in the study. The majority were males (81.7%), aged 26–35 years (64.9%), and worked in community pharmacies (81.7%). Nearly half of the participants reported optimal practice regarding checking drug interactions before dispensing any drug. Factors associated with the practice of checking DDIs were found to be gender, perceived workload, perceived knowledge, and attitude variables. Regarding the practice of asking patients about their prescription and OTC drugs, there were statistically significant differences between hospital and community pharmacists. Conclusions: Our findings on both community and hospital pharmacists in Saudi Arabia reveal that pharmacists’ attitudes and perceived knowledge might influence the practice of pharmacists toward DDIs.

Background: Levetiracetam (LEV) is among the most frequently prescribed antiseizure medications, yet its tolerability is limited in some patients by psychiatric and behavioral adverse events. Because psychiatric comorbidity and psychotropic co-medication are common in epilepsy, attributing such events to LEV rather than to the underlying disease remains difficult. Thus, we sought to characterize LEV-associated psychiatric reporting and to determine whether it differs by age, sex, and concurrent psychotropic use. Methods: Different safety reports submitted to the FDA Adverse Event Reporting System (FAERS) from 2013 through 2022 were extracted and joined by case identifier, restricted to LEV as the primary suspect drug, with co-administered antidepressants and antipsychotics flagged. Reports lacking age or sex were excluded. Groups were compared using the t-test and the chi-square or Fisher exact test, with odds ratios referenced to LEV without a recorded antidepressant or antipsychotic. Results: Among 928 reports (mean age 48.0 ± 20.1 years; 60.9% female), dizziness (30.1%), anxiety (16.5%), agitation (10.3%), insomnia (9.8%), depression (9.6%), and amnesia (8.8%) accounted for more than 85% of adverse events. The profile was age dependent. Agitation was reported more often for adolescents than for adults (adjusted OR 3.22, 95% CI 1.67–6.20). Psychotropic co-medication was recorded in 230 reports (24.8%). Furthermore, anxiety (OR 2.07, 95% CI 1.43–2.99) and depression (OR 1.82, 95% CI 1.15–2.89) were reported more frequently in co-medicated reports, whereas dizziness (OR 0.59, 95% CI 0.42–0.84) and agitation (OR 0.44, 95% CI 0.25–0.83) were reported less frequently. The association with agitation was attenuated and was no longer statistically significant after adjustment (aOR 0.61, 95% CI 0.33–1.14). Conclusions: These findings characterize age- and co-medication-related differences in psychiatric adverse-event reporting with levetiracetam. After correction for multiple comparisons, agitation remained more frequently reported among adolescents, while other apparent age-related differences were not statistically significant. These findings provide descriptive pharmacovigilance evidence regarding psychiatric adverse-event reporting patterns associated with levetiracetam.