 <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] ), nefazodone, HIV protease inhibitors (such as nelfinavir), rifamycins (such as rifampin, rifabutin), ritonavir, St. John's wort, certain anti-seizure medicines (such as carbamazepine, phenytoin), among others. Aprepitant can both speed up or slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include elacestrant, flibanserin, lomitapide, pimozide, among others. If you take warfarin, this drug may affect how well warfarin works in your body. Your doctor should test your blood during the 2 weeks after your aprepitant treatment to measure how well warfarin is working. This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Discuss with your doctor or pharmacist if you should use additional reliable birth control methods while using this medication and for 1 month after stopping this medication. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well </s>