Can loperamide be altered to cross the blood brain barrier?

Loperamide is designed to act primarily on the peripheral opioid receptors in the gut and has limited ability to cross the blood-brain barrier (BBB) due to its structure and active efflux by P-glycoprotein. While theoretically possible to modify its chemical structure to enhance BBB permeability, such alterations could change its pharmacological profile and potentially lead to central nervous system side effects. Research into drug modifications should consider both efficacy and safety implications.