Penicillin V as first-line treatment of pneumonia in primary care: a registry-based study.

Objectives: Penicillin V (PcV) is considered the first-line treatment for community-acquired pneumonia in Scandinavian countries, although data supporting this recommendation are scarce. Thus, this study aimed to compare PcV and amoxicillin regarding the risk of treatment failures in children aged >5 years and adults treated for pneumonia in primary care.

Methods: In this retrospective study of healthcare registry data from four regions in Sweden with 2.3 million inhabitants, we included 34 306 primary care cases of pneumonia from February 12, 2018 to December 3, 2021. Adjusted odds ratios (aORs) and 95% CIs for treatment failure days 1 to 28 (primary composite endpoint: hospitalization for lower respiratory tract infections [LRTI] or all-cause mortality; and secondary endpoint: antibiotic switch) were calculated using logistic regression analysis. A propensity score matched analysis was conducted.

Results: PcV was prescribed in 19 761 cases, amoxicillin in 2363 cases, doxycycline in 9830 cases, and other antibiotics in 2352 cases. Hospitalization for LRTI or all-cause mortality occurred in 4.9% of cases treated with amoxicillin vs. 3.8% of cases treated with PcV (aOR, 1.07; 95% CI, 0.87-1.32). Antibiotic switch occurred in 8.9% of cases treated with amoxicillin vs. 14% of cases treated with PcV (aOR, 0.58; 95% CI, 0.50-0.67). The corresponding ORs of the propensity score match analysis were 1.13 (95% CI, 0.86-1.49) for hospitalization for LRTI or all-cause mortality and 0.55 (95% CI, 0.45-0.65) for antibiotic switch.

Conclusions: This study showed no difference in risks of hospitalization for LRTI or all-cause mortality between PcV and amoxicillin for pneumonia in primary care.