Which abbreviation indicates the method of taking medication under the tongue?

The abbreviation that indicates the method of taking medication under the tongue is "sl," which stands for sublingual. This route of administration allows the medication to be absorbed directly into the bloodstream through the tissues under the tongue, providing a quick onset of action. Sublingual medications are formulated to dissolve quickly, facilitating rapid absorption without needing to pass through the digestive system, which can delay effects.

Other common abbreviations include "po," which means orally and refers to medications taken by mouth; "pv," which indicates the vaginal route; and "pr," which stands for rectally. Each of these methods has distinct uses and routes of absorption that are different from sublingual administration, which is why "sl" is the correct choice for medications taken under the tongue.