Chapter 33.4, Problem 5MI

Summary Introduction

To compare:

The three main classes of commonly abused drugs.

Introduction:

The term used for action of drugs on the human body is pharmacodynamics. The term used for body’s response on receiving the drug is pharmacokinetics. All drugs act in a specific manner in the body. There are two types of drugs, agonists and antagonists.

Explanation of Solution

The three main classes of commonly abused drugs are as follows:

1. Opioids − These drugs act on the receptors that are located on the cell membranes of neurons. Opioids inhibit the release of neurotransmitter that affects the proper functioning of the nervous system. Examples of opioids are codeine, morphine, and hydrocodone.

2. CNS depressants − These drugs increase the activity of gamma-aminobutyric acid, GABA, and inhibit the activity in the brain. Examples of CNS depressants are Xanax, Ativan, and Valium.

3. Stimulants − These drugs increase the levels of catecholamine and agonistic activity. Stimulants also increase the level of dopamine in the brain. Examples of stimulants are Ritalin, Concerta, and Methylin.