Drugs of Abuse

Pharmacology and Molecular Mechanisms

Sherrel Howard

• Publisher: Wiley-Blackwell
• Year: 2014
• Print ISBN:
  9781118288450
• eBook ISBN:
  9781118850145
• Edition: 1
• Topic: Medicine
• Subtopic: Pharmacology

Drug abuse has been, and continues to be, a global societal issue with diverse sets of impacts. Drugs of Abuse: Pharmacology and Molecular Mechanisms introduces the basic principles of pharmacology and neuroscience of drug abuse. Understanding the chemistry of commonly abused drugs and their impact on brain function will provide students and researchers with a more profound understanding of the molecular basis of drug abuse and addiction.

Drugs of Abuse: Pharmacology and Molecular Mechanisms opens with a brief history of drug use and abuse. Subsequent sections look at specific families of drugs, including stimulants, depressants, and hallucinogens among others, and explore how their chemical make-up interacts with brain function. The final chapter provides a brief overview of clinical substance abuse treatment.

Providing a concise, accessible introductory overview of the topic, Drugs of Abuse: Pharmacology and Molecular Mechanisms will be a valuable resource for students, researchers, and others interested in how drugs interact with the brain.

Introduces readers to the basic principles of neuroscience and pharmacology as related to drug use and abuse. 

• Explores how the chemical make-up of drugs interact with the brain and can lead to addiction
• Includes coverage of a wide array of commonly abused families of drugs, including stimulants, depressants, hallucinogens, and others.
• Provides an essential introduction to the chemical and molecular underpinnings of drug use and abuse

1
Introduction

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Learning Objectives

The student will learn:

1. To identify when drug seeking becomes a problem.
2. What is the common link between many dependence-producing drugs?
3. To recognize the common attributes of dependence- producing drugs.
4. Identify the factors involved in drug dependence.

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We are a society of drug users. If our headaches or a muscle twinges a little, we take a pill. If we are nervous, “stressed-out,” or just cannot sleep, we take a tranquilizer or sleeping pill. If we do not eat a balanced diet, we take vitamin pills, and then diet pills so we can lose the weight we gained because we were not eating a balanced diet. In fact, it almost seems that there is a pill for pretty much everything that is not “just right.” As a society we have come to depend on pills, as if the pills would correct any mistakes we make, cure any loneliness or failure we have. However, if we examine societies through the ages, we can see that our society today, is not that different, we just have a wider selection of “cure-alls.”

For many thousands of years humans have searched for ways to modify or alter their feeling of well-being and consciousness. We have sought to increase our awareness, decrease boredom, increase alertness, physical prowess, stimulate creativity, or enhance our senses. Throughout the ages we have used potions, plants, extracts, tonics, pills, and injections. All were used to achieve an altered state of consciousness. While there are many ways to achieve this altered state of reality, over the centuries man has chosen to use psychoactive drugs.

Most of the psychoactive drugs consumed were done so by personal choice, rather than professional advice. While society today does not generally approve of this unauthorized use of mind-altering drugs, this has not always been the case. Many of the drugs of abuse have had a very colorful history and have often been used not only for their ability to alter perception, but also to gain political, economic, and religious control over a given population.

ORGANIZATION

The first two chapters of this book lay the groundwork or background information for the drugs that will be covered. In this chapter we begin our studies on drug abuse with a brief historical perspective and an introduction to the attitude of society today toward most addictions. We will define the processes that are related to forming an addiction, and define terms that we will be using throughout this book.

Chapter 2 describes the basic steps in the synthesis and metabolism of the neurotransmitters that are primarily involved in producing the effects of a drug. The receptors of these neurotransmitters will also be considered as a potential site to enhance or inhibit drug effects. In Chapters 3–11, the different categories of drugs are examined in regard to their mechanism of action and their clinical and nonclinical usage. The final chapter examines treatment programs and the success and failures of these programs.

The primary focus throughout this book is the mechanisms by which abused drugs exert their effects on both the central and peripheral nervous system. We will examine how tolerance and dependence, both physical and psychological, develop.

OPIUM, MORPHINE, AND HEROIN

Opium has a long and colorful history. Opium is an extract of the opium poppy, and the first recorded use of opium was in Assyria, dating back to the seventh century BC. However, records were also found in Samaria, now called Iran, in the year 4000 BC describing the harvest and production of opium. It was harvested and the opium extracted from the poppy seed in much the same way as it is today. The use of opium was also much the same as today, namely, reduction of pain and diarrhea, and the altered mental state of euphoria and sedation was often considered an extra benefit. Because opium was so potent, both the rulers and the holy men used opium to exert control over society.

Figure 1.1 Flower of Opium Poppy.

Opium is referred to in the Iliad, where Helen of Troy mixed a potion of “freedom from grief and pain,” and everyone from Hippocrates to Galen described its various uses. During the Dark Ages, around 1000 AD, the use of opium was described in the Arab world. The Arabs then took opium to China in the ninth century and later China imported opium from India. The Chinese initially used opium to treat dysentery. Somewhat later the East India Company imported opium from China, taking it to Portugal. This use was not for the treatment of any disease.

By the seventeenth century opium was a common ingredient in many potions throughout Europe, but there were so many ingredients in these potions that very little harm was caused to the patient because of the opium content. Around the turn of the eighteenth century, the medical profession became concerned with the lavish use of opium. They were largely ignored, as most people saw no great harm coming from its use. In 1800, a German pharmacist isolated a pure alkaloid base from opium and published a paper describing the compound. This paper was completely ignored by the professional community. Twenty years later he published the same paper, only this time he called the substance morphine, the god of sleep and the paper received a lot of attention.

During the seventeenth century, all medicines were taken orally since intravenous injections were very difficult. In 1656 Christopher Wren introduced the hypodermic needle. This was not as much of an improvement as you might think as the needle had a blunt end. To use the hypodermic needle, an incision had to be made in the skin before the needle could be introduced. Surprisingly, it took many years before a bevel was added to the needle, making it possible to insert the needle without cutting the skin first. However, the introduction of the hypodermic needle and syringe added a whole new dimension to the use of opium.

Economics soon became the primary concern in the Opium Wars beginning in Europe. The British were producing opium in India, to sell to the Chinese in exchange for tea. During the American Civil War, opium or a derivative and a hypodermic needle were given to soldiers to alleviate the pain of injuries obtained during battle. Morphine was so widely used that the addiction to morphine was called the “soldier's disease,” but was considered preferable to alcohol, as the soldiers were quieter after using morphine. Morphine was now so readily available that it was used to treat any and all painful states.

By the nineteenth century morphine was added to many over-the-counter remedies. It was used to cure alcoholics of their drinking habit and was very popular. McMunn's Elixir of Opium and Mrs. Winslow's Soothing Syrup were the most popular, containing heroin, opium, cocaine, and some alcohol. Mrs. Winslow's Soothing Syrup was used to stop crying, pain from teething, and any small cough that occurred in infants. Children were dying from the overuse of Mrs. Winslow's syrup by young, overprotective mothers.

By the 1900s, opium, heroine, and morphine were so commonly used that a very nice leather pouch could be purchased at Macy's Department Store containing, a vial of heroin, a vial of cocaine, and a reusable hypodermic needle. These kits were well advertised in newspapers and magazines, and at the time, the use of these drugs was well accepted by society.

In 1914, spurred on by the overuse of Mrs. Winslow's Soothing Syrup, the Pure Food and Drug Act and the Harrison Narcotics Act were passed. These two Acts eliminated the over-the-counter sale of narcotics in any form. Of course the passing of these laws made way for the illegal sale of drugs throughout the country.

This brings us to the twentieth century, where drug abuse is no longer accepted by society, and various ways to stop drug abuse where funded by the government, namely, treatment, intervention, and prevention (“just say NO”). Treatment centers sprung up around the country, primarily on the East coast where heroin addiction was being treated with the replacement drug, methadone. The different interventions were an attempt to bring the heroin ...

Table of contents

• Cover
• Titlepage Text
• Copyright
• Dedication
• Contributor List
• Preface
• Acknowledgments
• Chapter 1: Introduction
• Part I: Stimulants
• Part II: Depressants, Sedative Hypnotics, and Anxiolytics
• Part III: Dissociative Anesthetics
• Part IV: Analgesics
• Part V: Hallucinogens
• Part VI: Recovery and Relapse
• Index