Pharmacology: Effects, Uses, and Risks

• Drugs can be both helpful and harmful.

• Drugs impact the treatment of medical and psychological conditions.

• Medications that are prescribed and OTC can cure diseases, ease pain, calm fears, alleviate anxiety and frustration, relieve sleeplessness, and treat many health problems.

• Drug technology and the availability of prescribed and OTC medications have improved the health status of millions, and can extend life expectancy.

• Even when carefully monitored, drugs can cause adverse reactions, iatrogenic illnesses, and death.

• It is important to be aware of the potential for physical and psychological dependence.

Definitions and Key Terms

• Pharmacology is the study of the fate of drugs in the body and their actions.
• Pharmacy is the science of drug preparation.
• Therapeutics is the treatment of disease by drugs and other means.
• A drug is any substance other than a normal constituent of the body (excluding food, water, and oxygen) that alters body function when introduced into a living organism.
• Drugs can either treat disease via therapeutic application or cause disease via toxicity.
• Medicine refers to drugs that heal unhealthy tissue, ease pain, prevent illness or diagnose health conditions.
• Psychoactive/psychotropic substances are any substances capable of altering one's feelings, moods, or perceptions.
• Stimulants, depressants, hallucinogens, opiates, and inhalants are examples of psychoactive/psychotropic substances.
• Examples of drugs are cold and hay-fever remedies, penicillin given on prescription, LSD bought illegally and vitamin C in orange juice.

Drug Classifications

• Central Nervous System (CNS) depressants are psychoactive drugs that reduce the function of the CNS.
• Alcohol, barbiturates, tranquilizers, benzodiazepines, barbiturates, and anti-depressants are examples of CNS depressants.
• CNS stimulants are psychoactive drugs that stimulate the function of the CNS.
• Caffeine, amphetamines, ice, and cocaine are examples of CNS stimulants.
• Hallucinogens or psychedelic drugs are psychoactive drugs that produce hallucinations and distortions of reality such as LSD and mescaline.
• Dissociative anesthetics are psychoactive drugs that inhibit pain by cutting off or dissociating the brain's perception of it such as dextromethorphan, ketamine, and Phencyclidine (PCP).
• Narcotic analgesics are psychoactive drugs derived from the Oriental poppy plant, relieve pain, induce euphoria and sleep, and create mood changes.
• Opium, codeine, heroin, Demerol, dragon, morphine, methadone, Vicodin, and oxycontin are all narcotic analgesics.
• Inhalants are psychoactive drugs that enter the body through inhalation, producing mind-altering results and effects.
• Toluene, plastic cement, pain, gasoline, paint thinners, hair sprays, and anesthetic gases are examples of inhalants.
• Cannabis is the scientific name for marijuana.
• The active ingredient in cannabis is delta-9 tetrahydrocannabinol, or THC.
• Cannabis produces euphoria, relaxed inhibitions, increased appetite, and disoriented behavior.
• Hashish and hashish oil are examples of cannabinoids and synthetics like Dronabinol.

How Drugs Work

• Pharmacokinetics: Study of the action of drugs within the body, including routes and mechanisms of absorption; rate at which a drug's action begins; duration of the effect; biotransformation of a substance in the body; the effects and routes of excretion of a drug's metabolites.
• Pharmacodynamics: Study of how a drug acts on a living organism and the pharmacologic response observed relative to the concentration of the drug at an active site in the organism.

Sources of Variation in Drug Response

• Pharmacodynamic Variation: Changes in tissue response caused by disease processes, drug interactions, previous drug history, and dosage in children of different ages; dosage for adults should take body size and build into account.
• Bioavailability: Degree of activity or amount of an administered drug or other substance that becomes available for activity in the target tissue; variety of physiologic and pathologic factors in GI tract and liver; diarrhea; vomiting; steatorrhea; biliary obstruction.
• Compliance: Not following directions due to complexity and inconvenience, continuity and ease of contact with physician, or psychiatric illnesses.

Routes of Administration

• A drug must be absorbed, reach its site of action, and interact with the target tissue, regardless of the administration route.
• Processes related to drug administration occur at different speeds depending on the route of administration.
• Therapeutic objectives and drug properties can play a role in administration route choice.
• The FDA has identified approximately 110 different routes of administration.
• Routes of administration are direct local application of the drug to the area that needs treating, application to ointments, creams, lotions, powders, and sprays to the skin, eye drops and ophthalmic ointments, nose drops and sprays, ear drops, solutions/sprays for use in the mouth, rectum, vagina, and urethra application of drug at its action site, oral mucosa (sublingual), and rectal mucosa (suppositories).
• Other routes of administration are stomach and intestine, absorption through the lungs, gases, vapors, asthmatic medications, subcutaneous/intravenous/intra-arterial/intramuscular/intrathecal injection, rapid/slow infusion, etc.

Substance Use, Misuse, and Abuse

• Substance use is drug taking in the most general way, encompassing misuse and abuse.
• Substance misuse is inappropriate use of legal drugs intended to be medications.
• Substance abuse is any use of an illegal drug, or the use of a legal drug when it is detrimental to health.

Reliance on Drugs

• Tolerance is an acquired reaction to a drug, caused by continued intake of the same dose having diminishing effects and is a cross-tolerance that can transfer from one drug to another in the same general category.
• Psychoactive drugs have a strong potential for dependence development which is a general term that refers to the need to keep consuming a drug for psychological or physical reasons.
• Patterns of nervous system function altered which may lead to continued use of drugs if benefits are noticed, potentially at higher dosages which can lead to the development of dependence
• There is a desire to use a particular drug, turning into a habit, to maintain a sense of well-being; abrupt withdrawal would not initiate fully expressed withdrawal illness, with minor symptoms.
• The body becomes reliant on a drug and requires it since body tissues have adapted, and this is determined as a need.
• The body needs the drug to maintain homeostasis or dynamic balance
• If the drug is not taken or is suddenly withdrawn, withdrawal illness or abstinence syndrome results.

Addiction & Addictive Behavior

• Addiction, as defined by the American Psychological Association (APA), is continued involvement with a substance or activity despite ongoing negative consequences that has 4 criteria of physiological addiction.
• Craving, tolerance, withdrawal and relapse are the components of physiological addiction.
• Addictive behaviors are habits that are out of control, resulting in a negative impact on a person's health.
• Addiction is commonly associated with drug use, but can include shopping, eating, gambling, sex, television, video games, work, and alcohol.
• Addictive exercisers compulsively use exercise to meet needs of intimacy, nurturance, self-esteem, and self-competency.
• Addictive exercisers are often women, but men are developing unhealthy exercise patterns and abusing steroids, which can have negative consequences such as alienation of family and friends, injuries, and craving for more.
• Club drugs are substances commonly used in nightclubs, music festivals, raves, and dance parties to enhance social intimacy and sensory stimulation such as 3,4-methylenedioxymethamphetamine (MDMA/ecstasy), gamma-hydroxybutyrate (GHB), flunitrazepam (Rohypnol), and ketamine (Ketalar).
• Club drugs are often taken orally in combination with each other, alcohol, or other drugs, and are popular because of their low cost and convenient distribution as small pills, powders, or liquids.
• Meth is a powerfully addictive stimulant which can be snorted, injected, smoked, or ingested orally and can be easily made using over-the-counter drugs and materials.
• Small doses of meth increase alertness and decrease appetite, however, doses can lead to convulsions, hallucinations, and death and users experience tolerance immediately.
• Meth abuse is a serious problem in North America, where it is often referred to as "crystal meth", and cold/allergy medications are kept behind the counter and may contain fertilizer/ammonia.
• Dealers are also mixing cannabis with meth.

The Process of Addiction

• One must be exposed to a drug or behavior to become addicted, and it can begin after a person finds a drug or behavior enjoyable.
• An initial pleasure gradually (or quickly) becomes a focal point, replacing any unpleasant feeling or sensation.
• Addiction is distinguished by obsession, or excessive preoccupation with behavior and the overwhelming need to perform it.
• Individuals devote an increasing amount of energy, time, and money to pursuing the drug/behavior and develop a compulsion for it.
• Over time, repeated exposure to a drug/behavior continues despite the negative effects, normal life degenerates, and tolerance and withdrawal develop.
• There is an inability to reliably predict whether any isolated occurrence of the behavior will be healthy or damaging such as physical damage, legal trouble, financial problems, academic failure, and family dissolution.
• Addiction is characterized by is the inability to perceive that the behavior is self-destructive.

Models of Addiction

• A model proposes addiction is caused by a variety of factors operating together.
• Serotonins and GABA are key factors.
• Several components may predispose addiction such as cultural expectations, attitudes, and messaging, and social learning theory.

Factors That Contribute to Addiction

• Genetic predisposition, personality traits, attitudes and beliefs, and interpersonal skills can contribute to addiction.
• Home and family, school, and peers can contribute to addiction.
• Youth subculture, modeling and advertising, and technological advances can contribute to addiction.

Impact on Family and Friends

• A person is "addicted to the addict"
• The person assumes responsibility for meeting the addict's need and neglects their own.
• Some people knowingly or unknowingly protect addicts from the natural consequences of their actions.

Treatment

• Treatment involves a planned process of confrontation by people who are important to the addict.
• Treatment aims to allow the addict to understand the destructive nature of the addiction
• Treatment can involve abstinence to refrain from the addictive behavior.
• Detoxification is when one adjusts physically and cognitively to being free from the influence of addiction.
• All 3 strategies for addiction treatment studied by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) via Project Match were equally competent.
• The focus for treatment selection should be on choosing a program that was competently run.

Withdrawal Illness, Relapse and Overdoses

• Withdrawal is an uncomfortable toxic response of the body as it attempts to maintain homeostasis in the absence of a drug.
• Withdrawal symptoms may include mild to severe irritability, depression, nervousness, digestive difficulties, and abdominal pain.
• Relapse is an isolated or complete return to addictive behavior.
• Relapse prevention requires the addict and significant others to recognize the signs of imminent relapse and to develop a plan for responding to the signs.
• Relapse is not a failure or lack of desire to stay well.
• Naloxone is the first line of treatment for opioid overdose, which can temporarily reverse opioids overdose as is the case with Fentanyl,
• Workplace Safety & Prevention Services has a free 30 minute course on a Naloxone awareness at https://shop.wsps.ca/products/naloxone-awareness