Diphenhydramine and its salts for parenteral use are classified as which schedule?

Diphenhydramine and its salts are classified as Schedule 2 substances for parenteral use due to their potential for significant effects on the central nervous system, particularly sedation and anti-cholinergic effects. Schedule 2 drugs are those that, while available for sale to the public, require a pharmacist's intervention for dispensing, which often includes providing necessary patient counseling regarding their use—primarily because of the risks associated with misuse or adverse effects.

This classification is designed to balance accessibility for patients who need medications, such as those for allergic reactions or motion sickness, with the need for oversight to ensure safe and appropriate use. The management of such medications is crucial, as improper use can lead to serious complications or interactions with other substances, highlighting the importance of a pharmacist's expertise in guiding patient use.

In contrast, other schedules involve different levels of control based on their risk of misuse, such as Schedule 1, which is typically reserved for prescription-only medications, and Schedule 3, which can be available without a prescription but still under pharmacy guidance. Unscheduled substances may be readily available without any restrictions, lacking the need for pharmacist consultation.