Zinc treatment may inhibit the absorption of these medicines,. Keep out of reach of children. In case of overdose get medical help or contact a Poison Control Center right away. Ask a doctor or pharmacist before use if you are taking minocycline, doxycycline, tetracycline or are on Coumadin (warfarin) therapy. When using this product do not take on an empty stomach (to avoid possible minor stomach upset). Stop use and ask your doctor if symptoms persist more than 7 days If pregnant or breast-feeding, ask a healthcare professional. Do not use for treatment of influenza or allergies. This product is intended only to reduce the duration of the common cold and its symptoms.