Prevalence, Safety Evidence, and Determinants of Medicine Use during Breastfeeding among Women in Kampala, Uganda

Background Breastfeeding is essential for child health and survival, yet breastfeeding mothers often require medications to manage postpartum and chronic conditions, raising concerns about potential infant safety. Limited research has been undertaken on medication practices during lactation, especially in low-resource settings like Uganda. The study aimed to investigate the prevalence of medicine use, evidence about safety, and factors that influence medicine use among breastfeeding women in Kampala, Uganda. Methods We conducted a cross-sectional study using a structured questionnaire in six healthcare clinics in Kampala, Uganda, from September 2023 to January 2024 among breastfeeding women. We enrolled breastfeeding women aged 18 and older. We used modified Poisson regression to identify factors associated with medication use. We evaluated medication safety during breastfeeding and Relative Infant Dose (RID) using Hale’s Lactation Risk Category, the LactMed database, and the WHO Anatomic Therapeutic Chemical (ATC) classification system. Medicines with a RID > 10% were flagged as potentially giving higher infant exposure. Results Of the 294 enrolled breastfeeding women, 168 (57.1%) practiced exclusive breastfeeding. A total of 232 women (78.9%) had used medicines in the preceding six months, and 98 (67.3%) of women reported obtaining medicines without prescriptions. Medicine use was significantly more common among women with younger infants (adjusted prevalence ratio [aPR] = 1.4; 95% CI: 1.1–1.6), higher educational attainment (aPR = 1.3; 95% CI: 1.1–1.4), and those without chronic health conditions (aPR = 1.1; 95% CI: 1.1–1.3). Antibiotics were the most frequently used class of medicines, with amoxicillin and ampicillin/cloxacillin reported by 112 women (38.1%). Metronidazole, an antimicrobial agent, was also commonly used, reported by 137 women (46.6%), raising concerns due to its potential for high infant exposure (estimated between 11–24%). Analgesic use was also high, particularly paracetamol, used by 183 women (74.5%). Overall, 61.0% of medicines used were classified as compatible with breastfeeding, 35.4% as probably compatible, and 2.6% as possibly hazardous. Medicines requiring cautious use included frusemide, cyproheptadine, metronidazole, phenylpropanolamine, acetaminophen combined with caffeine, and griseofulvin owing to risks of significant infant exposure, potential interference with lactation, or limited safety data. In contrast, dihydroartemisinin/piperaquine phosphate, artemether/lumefantrine, cefixime, pyrazinamide, and ethambutol were frequently used and considered acceptable during lactation. However, it is important to note that controlled studies assessing their safety specifically in breastfeeding women are lacking. Conclusion Breastfeeding women frequently used medicines, many of which were self-prescribed, including some that necessitate careful consideration due to safety concerns. Findings underscore the need for targeted education on safe medicines practices to support women's informed decision-making, conduct pharmacokinetics studies in breast milk, and impact on lactation.