 <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]  Your doctor should test your blood during the 2 weeks after your fosaprepitant 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. Fosaprepitant is very similar to aprepitant. Do not use aprepitant while using fosaprepitant. Does Emend Vial interact with other drugs you are taking? Enter your medication into the WebMD interaction checker Check InteractionThe overdose of Emend (Fosaprepitant) Intravenous: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.  Notes Not applicable.  Missed Dose It is important to get each dose </s>