One of the fastest means of getting drugs into the bloodstream is

• A. Orally
• B. Intravenously
• C. Intranasally
• D. Topically

Answer: (B)

Delivering a drug directly into a vein provides the fastest entry into systemic circulation. Intravenous administration puts the drug immediately into the bloodstream, giving almost instant availability, 100% bioavailability, and precise control over dose and rate of onset. In contrast, oral dosing must travel through the gastrointestinal tract and liver, where absorption can be slow and variable and some of the drug is lost to first-pass metabolism. Intranasal and topical routes can reach the bloodstream, but their absorption is slower and more variable due to mucosal or skin barriers. This combination of immediacy and reliability makes intravenous administration the quickest way to get a drug into the bloodstream.