The impact of tirzepatide and glucagon-like peptide 1 receptor agonists on oral hormonal contraception.

BACKGROUND: Tirzepatide is a dual glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist (RA) whose mechanism of action leads to a greater effect of gastric emptying (GE) than typical GLP-1 RAs. After the first dose of tirzepatide, GE is most substantially delayed. The drug then undergoes tachyphylaxis after subsequent doses. Although data on GLP1-RAs have historically demonstrated a lack of impact on bioavailability of oral hormonal contraceptives, manufacturer recommendations for tirzepatide indicate an interaction exists. OBJECTIVES: The objectives of this literature review were to review trial data on differences in the impact of tirzepatide and GLP-1 RAs on oral hormonal contraceptives and provide an analysis of safety data between oral contraceptives and incretin agents. METHODS: PubMed and Google Scholar were searched using the generic name for the GLP-1/GIP agent, the generic names for GLP-1 RAs and hormonal contraceptives, followed by the generic names plus the interacting medication. A total of 6 clinical trials were selected for inclusion in the literature review. RESULTS: Of the 6 articles included in the review, one investigated the use of tirzepatide and showed a statistically significant reduction in area under the plasma drug concentration-time curve, maximum concentration, and time to maximum plasma concentration when tirzepatide was concomitantly administered with an oral hormonal contraceptive. The remaining 5 studies involving GLP-1 RAs did not show a statistically or clinically significant difference of impact of the agents on oral hormonal contraceptives. CONCLUSION: It could be suggested that tirzepatide had a greater impact on absorption of oral hormonal contraceptives than other GLP-1 RAs. The rapid dose escalation and greater delay on GE enhanced the impact on oral medications such as contraceptives. This differed from other GLP-1 RAs and creates a unique need for enhanced provider and patient education regarding the management of this interaction and future studies to evaluate this interaction further.