Routes of drug administration: uses and adverse effects: Part 2: sublingual, buccal, rectal, and some other routes

Drugs are effective only if they reach their site of action. This can be achieved by direct application or in many indirect ways, usually via the bloodstream. Here I describe the uses and characteristic adverse effects of commonly used routes of administration. In part 1 I dealt with intramuscular injection and subcutaneous injection. Here I consider several other routes.