Pharmacy Chapter 5: Routes of Drug Administration

Disadvantages of Intravenous Administration

• Low safety due to risk of allergy or anaphylactic shock
• Sterility is crucial to prevent pyrogenic reaction
• Risk of spreading infection, including viral hepatitis
• Requires a professional person for administration
• Not suitable for oily and suspended drugs

Intramuscular Injection

• Suitable for solutions, suspensions, and oily drugs
• Offers better absorption than subcutaneous, but less than intravenous

Subcutaneous Injection

• Absorption rate is slower than IV and IM
• Suitable for non-irritant drugs in aqueous solution or fine suspension

Intradermal Injection

• Used for sensitive tests

Other Injection Routes

• Intra-cardiac injection
• Intrathecal injection
• Intra-bone marrow injection
• Intra-peritoneal injection

Mucosal Route

• Buccal or sublingual administration for systemic delivery of drugs
• Ocular administration for local delivery of drugs
• Vaginal, nasal, and rectal administration for systemic or local delivery of drugs

Inhalation

• Systemic delivery of drugs through high blood supply and wide surface area
• High bioavailability due to rapid absorption
• Many drugs can cause lung irritation as a side effect

Topical Route

• Local effect, but high lipid soluble drugs can be absorbed
• Transdermal drug delivery system (TDDS) enhances skin absorption, e.g., skin patches of nicotine