The document discusses the different routes of drug administration including oral, inhalation, injection, and topical application. It describes key aspects of each route such as how the drug is absorbed, how quickly effects are felt, and some risks. The routes covered are oral absorption from the gastrointestinal tract, inhalation through the lungs, intravenous and subcutaneous injection directly into the bloodstream or under the skin, intramuscular injection into muscles, and topical application through skin or mucous membranes absorption.

1. Chapter 5
The Actions of Drugs

2. ADME
Distribution of drugs
through the body
 Absorption
 Distribution
 Metabolism
 Elimination/Excretion
Additional factors
 Cultural issues
 Mechanisms of
tolerance & withdrawal
symptoms

3. Routes of Administration
 Oral
 Absorption from the gastrointestinal (GI) tract is a
complicated process
 Drugs must withstand the digestive processes and pass
through the cells lining the GI tract into the bloodstream
 Inhalation
 The drug moves from the lungs into the bloodstream
through capillary walls
 Effects are rapid because blood moves quickly from the
lungs to the brain

4. Routes of Administration:
Injection
 Intravenous (IV) injection involves putting the
drug directly into the bloodstream
 Effects are rapid
 High concentrations can be delivered
 Potential damages
 Subcutaneous injection (under the skin)
 “Skin popping”
 Can cause necrosis
 Intramuscular injection (into a muscle)
 Greater blood supply in muscles
 Less chance of irritation

5. Routes of Administration:
Topical Application
 Absorption through the skin can provide
slow, steady drug delivery
 Depending on the substance, can be a less
commonly used route of administration
 However, a range of topical applications
can be used with psychoactive substances
 Absorption through the mucous
membranes occurs more rapidly