People using antibiotics without a prescription seems to be a prevalent public health problem. Antibiotics were obtained through various means, including saving leftover prescriptions for later use, getting them from friends and family, or obtaining them from local markets "under the counter." Findings from a scoping review are published in Annals of Internal Medicine. When people take antibiotics without a prescription, they often take unnecessary medication or choose an inappropriate drug or dose. This practice is associated with avoidable adverse events and may also increase the risk for inducing antibiotic resistance. It is important to understand how prevalent nonprescription antibiotic use is and the factors that contribute to the issue.

Researchers from Baylor College of Medicine and the Center for Innovations in Quality, Effectiveness, and Safety reviewed 31 published studies to determine the prevalence of nonprescription antibiotic use in the U.S. and to examine the factors that influence that use. The prevalence of nonprescription antibiotic use varied from 1 percent among people visiting a clinic to 66 percent among Latino migrant workers. Storage of antibiotics for future use varied from 14 percent to 48 percent and a quarter of the people in one study reported intention to use antibiotics without a prescription.

Factors that contribute to nonprescription use include lack of insurance or health care access, cost of a physician visit or prescription, embarrassment about seeking care for a sexually transmitted infection, not being able to get time off of work to visit a clinic or physician's office, and several other reasons. According to the researchers, more studies are needed to quantitate nonprescription antibiotic use and explore potentially modifiable factors that contribute to unsafe practices.