 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  of Istradefylline Oral: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. A product that may interact with this drug is: elacestrant. Other medications can affect the removal of istradefylline from your body, which may affect how istradefylline works. Examples include rifamycins (such as rifabutin, rifampin), St. John's wort, drugs used to treat seizures (such as carbamazepine, phenytoin), among others. Cigarette smoking decreases blood levels of this medication. Tell your doctor if you smoke or if you have recently stopped smoking. Does Istradefylline 40 Mg Tablet interact with other drugs you are taking? Enter your medication into the WebMD interaction checker Check InteractionThe overdose of Istradefylline Oral: If someone has overdosed and has serious symptoms such as </s>