palbociclib + antacid

This is a combination of **palbociclib**, an oral small molecule inhibitor of cyclin-dependent kinase 4 and 6 (CDK4/6), and **antacid** agents. Palbociclib is primarily indicated for use in hormone receptor-positive, HER2-negative advanced or metastatic breast cancer. It acts by inhibiting CDK4/6, leading to cell cycle arrest at the G1/S phase transition. Antacids are a class of over-the-counter agents that neutralize gastric acid and are used for relief of symptoms related to gastric acidity. There is a clinically relevant potential for drug-drug interaction with palbociclib and acid-reducing agents due to the pH-dependent solubility of palbociclib, but data suggest local antacids, when staggered with palbociclib dosing and under fed conditions, do not significantly alter palbociclib exposure[5].