Do Thickening Agents Used in Dysphagia Diet Affect Drug Bioavailability?

Area of Science:

• Pharmacokinetics
• Drug Delivery
• Swallowing Disorders

Background:

• Dysphagia poses challenges for oral drug administration, increasing aspiration risk.
• Thickened liquids are commonly used to aid swallowing, but their effect on drug bioavailability is not well understood.

Purpose of the Study:

• To evaluate the impact of thickened liquids on the dissolution rate and in vivo bioavailability of levetiracetam.
• To assess the influence of different thickeners (modified maize starch and xanthan gum) and viscosity levels on drug pharmacokinetics.

Main Methods:

• In vitro drug release studies using a dialysis membrane method with four model drugs.
• In vivo pharmacokinetic studies in rabbits using levetiracetam mixed with thickened water.
• Analysis of blood samples via LC-MS/MS and development of an in vitro-in vivo correlation (IVIVC) model.

Main Results:

• In vitro studies showed reduced drug release with thickened liquids for most drugs.
• In vivo studies indicated no statistically significant differences in Cmax, tmax, or AUC for levetiracetam between control and thickened liquid groups.
• A good in vitro-in vivo correlation was observed, though not universally predictive across all thickness levels.

Conclusions:

• Administration of levetiracetam with commonly used thickening agents does not significantly alter its pharmacokinetic profile or bioavailability in rabbits.
• Thickened liquids can be considered a safe method for oral drug administration in dysphagia patients without compromising drug efficacy.