To speak with a Merck healthcare professional about Merck products, or to report an adverse experience with a specific Merck product, please call the Merck National Service Center at 800-444-2080.  The Merck National Service Center is pleased to assist you Monday through Friday from 8 AM to 7 PM ET.  Adverse experiences and product-related emergencies can be reported at any time by dialing 800-444-2080.