DiphenhydramineConsidered by most healthcare providers to be the gold standard of allergy medications, diphenhydramine provides relief from all types of allergic reactions. It's even used by emergency medical services to treat or prevent anaphylaxis.
The biggest side effect of diphenhydramine is drowsiness. This side effect is so common that diphenhydramine is also sold as a sleep aid. Generally, buying it as an allergy medication is cheaper than as a sleep aid, so be sure to read the labels. Remember, there is no difference, so a bottle of diphenhydramine purchased as an allergy medication will also help you fall asleep. For this reason, diphenhydramine is a good drug to have in your first aid travel kit. Diphenhydramine is also available as a cream, often combined with calamine lotion. It's used on bug bites and poison oak or poison ivy. As a cream, diphenhydramine should not make you feel drowsy.