The duration of phentermine therapy in the private healthcare sector of South Africa: A retrospective analysis
DOI:
https://doi.org/10.7196/SAMJ.2025.v116i3.3519Keywords:
Phentermine, Duration of therapy, Obesity, Short-term treatmentAbstract
Background. Phentermine is an amphetamine derivative and is globally the most used oral appetite suppressant for obesity. Its long-term (LT) use (a period >12 consecutive weeks) may be associated with amphetamine-like adverse effects. The US Food and Drug Administration has restricted its use to short term (ST) only (not longer than 12 consecutive weeks), specifically stated in the patient information leaflet. This serves as a prescribing guideline that is provided to assist both general and specialist practitioners in drug prescribing that is rational and safe, and to maximise patient outcomes and adherence. Since, to the researchers’ knowledge, there have been no studies previously undertaken in South Africa (SA) that provide data on the duration of phentermine use, this study was designed to determine whether the recommendations for the ST use of phentermine are reflected in the actual patterns of duration of this drug’s use.
Objective. To analyse the duration of phentermine therapy in the private healthcare sector of SA.
Method. A retrospective, cross-sectional drug utilisation review was conducted using longitudinal data from a SA pharmacy benefit management company’s medicine claims database. Paid claims for phentermine from 1 January 2015 to 31 December 2019 were extracted for analysis. The duration of phentermine therapy, patients’ age and gender and the specialty of the prescriber in patients receiving 15 mg or 30 mg of phentermine, respectively, were considered and evaluated. Statistical analyses were done with Statistical Analysis System (SAS) 9.4.
Results. Records of 3 361 patients (paid claims for phentermine) were found on the claims database during the study period. The duration of therapy (DOT) with phentermine was analysed, and results indicate that 2 472 (73.55%) patients received the drug ST, with the remainder receiving the drug LT. The mean (standard deviation (SD)) DOTs with 15 mg and 30 mg phentermine were 57.26 (58.72) days and 67.10 (52.01) days, respectively.
Conclusion. The study yielded highly encouraging results, affirming the ST use of phentermine. The evidence of LT use, however, opens new avenues for research. In the private healthcare sector of SA, the DOT with phentermine is not restricted to ST use, and some individuals may be exposed to the potentially harmful consequences accompanying LT therapy with phentermine.
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