Antihistamine / non-narcotic antitussive combinations are used to treat cough, cold symptoms, and allergies. These medications work by blocking histamine, which helps reduce allergy symptoms, and by suppressing the cough reflex. They come in different forms, including oral syrups and tablets. Examples include promethazine / dextromethorphan, chlorpheniramine / dextromethorphan (Coricidin HBP Cough and Cold, Children's NyQuil Cough and Cold), and dextromethorphan / doxylamine (Nyquil Cough). These options can help you manage your symptoms effectively.