Toxicity to pets

Cough medications are formulated with different and potentially multiple ingredients all of which can be toxic for pets. Opioids (e.g. codeine), decongestants (e.g., pseudoephedrine or dextromethorphan), expectorants (e.g. guaifenesin), and essential oils (e.g., menthol) are common cough medicine ingredients. These products, in overdose, cause nausea, vomiting, lethargy +/- collapse and slow breathing. Cough + cold, flu, or sinus medicines may contain pain relievers (e.g. acetaminophen) or antihistamines (e.g. diphenhydramine) that can lead to life-threatening clinical signs with overdose. The sugar substitute xylitol found in some cough medicine or cough drops is very toxic for dogs causing low blood sugar and serious liver injury.