Exercise and Sport Pharmacology

Mark Mamrack

• Publisher: Routledge
• Year: 2020
• ISBN:
  9781000067194
• Edition: 2
• Topic: Medicine
• Subtopic: Sports Medicine

Exercise and Sport Pharmacology is an essential book for teaching upper-level undergraduates or entry-level graduate students about how drugs can affect exercise and how exercise can affect the action of drugs. It leads students through the related pathology, exercise physiology, and drug action of many of today's chronically used medications, and discusses how drugs can affect exercise performance.

This new second edition of the book is divided into four parts: Section I provides the basics of pharmacology, exercise physiology, autonomic pharmacology, and the stress response; Section II presents chapters on major cardiovascular and respiratory drug classes; Section III describes frequently prescribed medications for such common conditions as diabetes, depression, pain, fever, inflammation, and obesity; and Section IV includes discussions of nutritional supplements and commonly used drugs such as caffeine, nicotine, cannabis, and performance-enhancing drugs. The second edition offers many updates, enhances muscle cell physiology, includes the involvement of the gut microbiome, and each chapter has a new section on the effects of aging.

In Sections II and III, chapters include an overview of the pathology that therapeutic drugs are designed to treat and how the drug works in the human body. In contrast to standard pharmacology texts, Exercise and Sport Pharmacology also includes the effect of exercise on the pathology of the condition and the effect of exercise on how the body responds to a drug. Each chapter has a section on whether the drugs under discussion have performance-enhancing potential. Section IV is concerned with self-medication and drugs or supplements taken without a prescription or with limited medical supervision.

Throughout, figures and tables as well as data from experiments in exercise pharmacology help to illustrate and summarize content. Each chapter opens with an on-going case example to preview and apply chapter content. In the text, boldface terms indicate which concepts are contained in the book's Glossary. Chapters conclude with a Key Concepts Review and Review Questions.

Section III
Frequently Prescribed Medications

9 Psychotherapeutic Agents

10 Lipid-Modifying Agents

11 Analgesics and Anti-Inflammatory Drugs

12 Antidiabetic and Antiobesity Drugs

9 Psychotherapeutic Agents

Abstract

Mental illness affects a significant portion of the population. Many of these people also suffer from poor cardiovascular health, and some experts feel these different types of illness are more related than they might appear. Many of the common types of mental illness respond to drug therapy. The drugs do not cure the disease, but they help the afflicted individuals cope and function better. Many of these drugs manipulate neurotransmitter levels in the brain. The neurotransmitters are important in how nerve cells communicate with each other. The ability of drugs to change neurotransmitter levels and alter brain function has led to a variety of theories concerning defective neurotransmitter signaling as a contributor to mental illness. Newer theories incorporate neurogenesis, where the production of nerve growth factors such as brain-derived neurotrophic factor (BDNF) can help produce new cells in certain regions of the adult mammalian brain. BDNF also contributes to the plasticity of the brain by increasing synaptic activity and the overall health of neurons. The lack of sufficient neurogenesis and plasticity may contribute to depression, bipolar disease, and age-related decrease in brain function.

Exercise is becoming an important intervention in mental health. Exercise can increase BDNF, neurogenesis, and neuronal plasticity, providing an overlapping model for how drugs and exercise contribute to mental health. Given these benefits combined with our increasing understanding of exercise’s ability to combat stress and improve cardiovascular health, it is becoming clear how exercise contributes to a healthy lifestyle.

CASE EXAMPLE

Megan’s brother Bo dealt with clinical depression through most of his school years. Bo had bad grades and generally did not “fit in.” He was arrested for drugs in ninth grade, and matters seemed to come to a head when Bo spent a couple of nights in the hospital after a suicide attempt. Drug intervention and therapy had some effect, but Bo often fell back into his old behaviors. When Bo was a sophomore in high school, his guidance counselor and his father encouraged him to take part in a school-based program to alter behavior of at-risk adolescents. That was where he discovered running. It took two weeks of supervised, controlled activity with his cohort group, but Bo soon found that running several miles every day in conjunction with taking medication helped him manage his emotions better. He liked the way he felt after running. He also liked the solitary aspect of running. He had hated playing soccer and baseball, because he felt like a failure most of the time and he didn’t fit in with the team. But running allowed him to just run. His grades improved, and he eventually was asked to join the cross country team his senior year. He declined, but deep down was pleased that he had been asked. Bo went on to earn his associate’s degree at the local community college and is now employed in the hospitality industry. He continues to run every day and to take his medication.

Learning Objectives

1. Appreciate the scope of the problems and the issues associated with mental illness.
2. Learn how the major classes of psychotherapeutic agents work.
3. Appreciate the relationship between a healthy mind and a healthy body, and how exercise can be a powerful adjunct therapy.
4. Understand how exercise can help a person control weight gain associated with antipsychotic drug use.
5. Appreciate how exercise can help a person deal with anxiety.
6. Learn the role of neurogenesis and neuronal plasticity in mental health.
7. Examine the evidence supporting a role for exercise in maintaining good mental health during the aging process.

Introduction

The prevalence of mental illness is hard to estimate for many reasons, including issues with diagnosis, cultural differences in acknowledging mental illness, and lack of health-care coverage. It has been estimated that serious mental illness will affect about 5% of the population with nearly one in five suffering from any mental illness (National Institute of Mental Health, “Statistics”). Treatment with medication and psychotherapy is expensive for individuals suffering from serious mental illness, and the total estimated costs soar when we include those associated with anxiety disorders, mood disorders, and drug or alcohol dependence. If people who experience these disorders at least once in their lifetime are included, the percentage of individuals in the population approaches 40% (National Institute of Mental Health, “Statistics”). Though some have taken issue with the data on the prevalence of mental illness and these other disorders, we can be certain that the overall number of individuals affected is very large. Costs associated with treatment of mental illness are predicted to approach the costs associated with cardiovascular disease. However, many medications are limited in their effectiveness and cause unwanted secondary effects. Unfortunately, they do not cure mental illness; they are just the best drugs available to help manage the disease.

As an adjunct to medication, exercise is becoming an important intervention in mental health. The relationship between mind and body has been studied and expounded upon for ages. Psychosomatic research has shown how changes in mental state can affect the physical state (Vitetta, Anton, Cortizo, & Sali 2005). For example, competitors put on their “game face” and focus to “slow the game down.” The physical state also affects the mental state. A healthy body is important for maintenance of a healthy mind, especially as we age. Exercisers are aware of the psychological changes that occur during physical activity and as a result of becoming fit. The fact that improved feelings of well-being and self-esteem follow exercise is well established. Regular exercise can improve clarity of thought, provide better sleep, and lower the risk of dementia later in life (Lövdén, Xu, & Wang 2013; Law, Barnett, Yau, & Gray 2014; Taspinar, Aslan, Agbuga, & Taspinar 2014). Because of its benefits, exercise is being considered as an adjunct therapy for mental illness (Stathopoulou, Powers, Berry, et al. 2006). Compared to the general population, individuals with mental illness are less physically fit, and some of the medications they take may exacerbate the problem (Galper, Trivedi, Barlow, et al. 2006).

This chapter examines the different classifications of psychotherapeutic drugs, including antipsychotics, anxiolytics, antidepressants, and mood stabilizers and how they work to treat different mental disorders: psychosis, anxiety, depression, and bipolar disorder. The chapter also examines whether exercise improves the condition of patients with the different mental disorders and whether exercise alters the action of psychotherapeutic drugs.

Mental Illness

The exact cause of most mental illnesses is not known, and it probably involves a combination of biological, psychological, and environmental factors. Mental illnesses result primarily from abnormal functioning of neuronal circuits or pathways in the brain. Defects or injuries in certain areas of the brain have been linked to some mental conditions. These defects can have a genetic or developmental component. Mental illnesses sometimes run in families, supporting a genetic component to the disease. Susceptibility is passed on to the next generation through inheritance of altered or defective genes. A genome-wide analysis identified specific variants underlying genetic effects shared among five disorders: autism spectrum disorder, attention deficit / hyperactivity disorder (see Chapter 8), schizophrenia, major depressive disorder, and bipolar disorder. Genomic sequence data for the five disorders were obtained from 33,332 cases and 27,888 controls of European ancestry. Four genetic loci were identified and two of them mapped to calcium-channel activity genes with possible effects on psychopathology. These results provide evidence that in the future, genetic analysis will be used for diagnosis of mental illness, replacing the descriptive syndromes in psychiatry (Cross-Disorder Group of the Psychiatric Genomics Consortium 2013). Genetics combined with imaging technology provide even greater possible advances in diagnosis and treatment of complex causes of mental illness (Moore, Sawyers, Adkins, & Docherty 2018).

Mental illness occurs from the interaction of genes and environmental factors (Schmidt 2007). A person who inherits a susceptibility gene for a mental illness does not necessarily develop the illness. How these genes interact with the environment is unique for every person, even identical twins. Environmental influences can occur at any time: in the individual’s parents (to be passed along in sperm or eggs), during the individual’s time in utero, early in life, or late in life. Environmental factors include drug abuse, trauma, stress, bacterial or viral infection, injury, lack of oxygen to the brain, poor nutrition, toxins, neglect, emotional stress (e.g., loss of a parent or spouse), and so forth. The combination of environmental factors and the expression of genetic variants that increase the s...