Which route has the medication enter oral mucosa under the tongue and reach the bloodstream within minutes?

• A. Sublingual
• B. Oral administration
• C. Intravenous injection
• D. Inhalation

Answer: (A)

Absorption through the sublingual mucosa is rapid because the under-tongue area is highly vascularized and has a thin epithelial barrier, allowing the drug to diffuse directly into the systemic circulation. This direct entry means the medication bypasses the liver’s first-pass metabolism, producing a quick onset of action—often within minutes.

This differs from oral administration, where swallowing sends the drug through the digestive system and liver metabolism before reaching the bloodstream, slowing onset. Intravenous injection enters the bloodstream immediately but does not involve absorption through oral mucosa. Inhalation delivers drugs via the lungs, which is also fast but again does not use the sublingual mucosa.