anders_CPH said:
Drug interaction alert relevant to constipation: if you take oral levothyroxine (Synthroid), GLP-1 agonists can reduce absorption due to delayed…
Gastric emptying studies and constipation: semaglutide delays gastric emptying by ~40% at steady state, as measured by acetaminophen absorption testing and scintigraphy[1].
Clinically relevant implications:
- Explains early satiety and nausea
- Affects absorption of co-administered oral medications
- Creates aspiration risk for procedures under anesthesia
- Contributes to constipation via slowed GI transit
Importantly, the gastric emptying delay attenuates with continued use (tachyphylaxis), which correlates with the transient nature of GI side effects.
References:
[1] Blundell J, et al. Diabetes Obes Metab. 2017;19(9):1242-1251.