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Chapter 1. Orientation to Pharmacology. Pharmacology. A science that draws on information from multiple disciplines, including: Anatomy Physiology Psychology Chemistry Microbiology. Four Basic Terms. Drug Any chemical that can affect living processes Pharmacology
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Chapter 1 Orientation to Pharmacology
Pharmacology • A science that draws on information from multiple disciplines, including: • Anatomy • Physiology • Psychology • Chemistry • Microbiology
Four Basic Terms • Drug • Any chemical that can affect living processes • Pharmacology • Study of drugs and their interactions with living systems
Four Basic Terms • Clinical pharmacology • Study of drugs in humans • Therapeutics • A.k.a. pharmacotherapeutics • The use of drugs to diagnose, prevent, or treat disease or to prevent pregnancy • Primary concern studied in this text
Orientation to Pharmacology • Properties of an ideal drug • The therapeutic objective • Factors that determine the intensity of drug responses • Therapeutics
Three Most Important Properties of an Ideal Drug • Effectiveness • Safety • Selectivity
Additional Properties of an Ideal Drug • Reversible action • Predictability • Ease of administration • Freedom from drug interactions • Low cost • Chemical stability • Simple generic name But because no drug is ideal…
Therapeutic Objective of Drug Therapy • To provide maximum benefit with minimum harm
Factors That Determine the Intensity of Drug Responses • Administration • Pharmacokinetics • Pharmacodynamics • Sources of individual variation
Fig. 1-1. The four basic pharmacokinetic processes. Dotted lines represent membranes that must be crossed as drugs move throughout the body.
Administration • Important determinants of drug responses: dosage size, route, timing • Medication errors • Patient adherence
Pharmacokinetics • Determining how much of administered dose gets to its sites of action • Impact of the body on drugs • Four major pharmacokinetic processes • Drug absorption • Drug distribution • Drug metabolism • Drug excretion
Pharmacodynamics • Impact of drugs on the body • Drug-receptor interaction • Binding of the drug to its receptor • Patient’sfunctional state • Influences pharmacodynamic processes • Placebo effects • Also help determine the responses a drug elicits
Sources of Individual Variation • Physiologic variables • Age, gender, weight • Pathologic variables • Diminished function of kidneys and liver • Genetic variables • Can alter metabolism of drugs and predispose patient to unique interactions • Drug interactions