Breakfast Habits in Patients Using Levothyroxine: Patient Experiences and Preferences.

Background: Levothyroxine (LT4) is recommended to be ingested in a fasting state, 30-60 minutes before breakfast to avoid interactions with food and drugs. In clinical practice, we noticed that this instruction may be inconvenient for patients. Therefore, we aimed to evaluate patient experiences and preferences concerning the recommended fasting administration of LT4.

Methods: Patients using LT4 were invited to complete a questionnaire. Regression analyses were performed to identify patient characteristics associated with taking LT4 close to or together with food and/or interfering drugs, feeling burdened with postponing breakfast, and preferring nonfasting LT4 ingestion.

Results: Of 463 invited patients, 410 completed the questionnaire (88.6%). Of these, 76.8% was female and median age was 57 years (interquartile range: 43-67). Nearly all patients (97.3%) reported to have received instruction on fasting LT4 ingestion, but only 30% adhered to this. Nonfasting LT4 intake was associated with use of co-medication (odds ratio [OR], 2.82; 95% CI, 1.77-4.47), treatment duration >1 year (OR, 1.76; 95% CI, 1.02-3.04), and male sex (OR, 1.67; 95% CI, 1.03-2.70). Approximately half of the patients reported being burdened with postponing breakfast and the majority (60.5%) expressed their preference for nonfasting LT4 ingestion. Interestingly, 25% omitted breakfast and 13.4% forgot their medication because of the fasting requirement. Furthermore, the majority (68.2%) of patients that used interfering drugs stated not to be instructed to separate these drugs from LT4.

Conclusion: This study highlights the burden associated with fasting LT4 ingestion, leading to nonadherence, irregular LT4 intake, and omitting breakfast. Given the clear preferences towards nonfasting LT4 ingestion, further research into alternative nonfasting administration methods is warranted.