Drug Interactions between HalfLytely and Bisacodyl and infigratinib

GENERALLY AVOID: Coadministration of gastric acid-lowering agents including locally acting antacids may reduce the plasma concentrations of infigratinib and its two active metabolites, BHS697 and CQM157. The interaction has been studied with the proton pump inhibitor, lansoprazole. Following coadministration with multiple doses of lansoprazole, infigratinib peak plasma concentration (Cmax) and total systemic exposure (AUC) decreased by 49% and 45%, respectively; BHS697 Cmax and AUC decreased by 44% and 32%, respectively; and CQM157 Cmax and AUC decreased by 55% and 72%, respectively. Reduced efficacy of infigratinib may occur.

MANAGEMENT: Concomitant use of infigratinib with locally acting antacids should generally be avoided. If coadministration with these agents is required, the manufacturer recommends that infigratinib be administered at least 2 hours before or 2 hours after locally acting antacids.

ADJUST DOSING INTERVAL: By increasing gastric pH, antacids may reduce the resistance of the enteric coating of bisacodyl tablets, resulting in earlier release of bisacodyl and gastric irritation and dyspepsia.

MANAGEMENT: The administration of antacids and bisacodyl should be separated by at least one hour.

GENERALLY AVOID: Concomitant use of stimulant laxatives (e.g., bisacodyl, sodium picosulfate) may increase the risk of serious gastrointestinal adverse effects associated with certain osmotic laxatives (e.g., polyethylene glycol (PEG), oral sulfate solution), such as colonic mucosal ulcerations or ischemic colitis. There have been isolated case reports of ischemic colitis occurring with the use of PEG-based bowel cleansing products in combination with higher dosages of bisacodyl (usually greater than 10 mg). Bisacodyl can cause colonic ischemia due to transient reduction in splanchnic blood flow. When administered in conjunction with an osmotic laxative such as PEG, increased intramural pressure secondary to increased peristalsis may lead to ischemic colitis and perforation.

MANAGEMENT: The manufacturers for some osmotic bowel cleansing products recommend avoiding the concurrent use of stimulant laxatives. However, stimulant laxatives, in particular bisacodyl and sodium picosulfate, are sometimes used with PEG in certain bowel cleansing regimens to help reduce dose volume and improve patient tolerability and acceptance. Please consult individual product labeling for specific recommendations and guidance. Patients using osmotic bowel cleansing products and stimulant laxatives who present with sudden abdominal pain, rectal bleeding, or other symptoms of ischemic colitis should be evaluated promptly.