Which route of administration is used when a drug is inserted into the vagina?

The route of administration used when a drug is inserted into the vagina is vaginal administration. This method involves placing the medication directly into the vaginal canal, allowing for localized or systemic effects depending on the formulation. The vaginal route is particularly useful for certain types of medications, such as antifungals, hormones, or contraceptives because it can achieve rapid absorption into the systemic circulation while also providing targeted treatment for local conditions, like infections or hormonal imbalances.

Other routes, such as rectal, nasal, or urethral, refer to drug administration via different body pathways, which are not applicable in this situation. Rectal administration involves the insertion of a drug into the rectum; nasal administration involves spraying or inhaling medication through the nose; and urethral administration targets the urethra. Therefore, for the specific case of drug insertion into the vagina, vaginal administration is the accurate and proper term to describe the action.