Pharmacological principles

1. Pharmacologic PrinciplesPharmacologic Principles

2. Pharmacologic PrinciplesPharmacologic Principles
DrugDrug
•Any chemical that affects the processes of Any chemical that affects the processes of
a living organisma living organism

3. Pharmacologic PrinciplesPharmacologic Principles
PharmacologyPharmacology
•The study or science of drugsThe study or science of drugs

4. Pharmacologic Principles: Drug NamesPharmacologic Principles: Drug Names
Chemical nameChemical name
•The drug’s chemical composition and molecular The drug’s chemical composition and molecular
structurestructure
Generic name (nonproprietary name)Generic name (nonproprietary name)
•Name given by the United States Adopted Name given by the United States Adopted
Name CouncilName Council
Trade name (proprietary name)Trade name (proprietary name)
•The drug has a registered trademark; use The drug has a registered trademark; use
of the name restricted by the drug’s owner of the name restricted by the drug’s owner
(usually the manufacturer)(usually the manufacturer)

5. Pharmacologic Principles: Drug NamesPharmacologic Principles: Drug Names
Chemical nameChemical name
•(+/-)-2-(p-isobutylphenyl) propionic acid(+/-)-2-(p-isobutylphenyl) propionic acid
Generic nameGeneric name
•ibuprofenibuprofen
Trade nameTrade name
•MotrinMotrin

6. Pharmacologic PrinciplesPharmacologic Principles
•PharmaceuticsPharmaceutics
•PharmacokineticsPharmacokinetics
•PharmacodynamicsPharmacodynamics
•PharmacotherapeuticsPharmacotherapeutics
•PharmacognosyPharmacognosy

7. Pharmacologic PrinciplesPharmacologic Principles
PharmaceuticsPharmaceutics
•The study of how various drug forms influence The study of how various drug forms influence
pharmacokinetic and pharmacodynamic activitiespharmacokinetic and pharmacodynamic activities

8. Pharmacologic PrinciplesPharmacologic Principles
PharmacokineticsPharmacokinetics
•The study of what the body does to the drug:The study of what the body does to the drug:
–AbsorptionAbsorption
–DistributionDistribution
–MetabolismMetabolism
–ExcretionExcretion

9. Pharmacologic PrinciplesPharmacologic Principles
PharmacodynamicsPharmacodynamics
•The study of what the drug does to the bodyThe study of what the drug does to the body::
–The mechanism of drug actions in living tissuesThe mechanism of drug actions in living tissues

10. Pharmacologic PrinciplesPharmacologic Principles
PharmacotherapeuticsPharmacotherapeutics
•The use of drugs and the clinical indications for The use of drugs and the clinical indications for
drugs to prevent and treat diseasesdrugs to prevent and treat diseases

11. Pharmacologic PrinciplesPharmacologic Principles
PharmacognosyPharmacognosy
•The study of natural (plant and animal) drug sourcesThe study of natural (plant and animal) drug sources

12. Drug Absorption of Various Drug Absorption of Various
Oral PreparationsOral Preparations
Liquids, elixirs, syrupsLiquids, elixirs, syrups FastestFastest
Suspension solutionsSuspension solutions 
PowdersPowders 
CapsulesCapsules 
TabletsTablets 
Coated tabletsCoated tablets 
Enteric-coated tabletsEnteric-coated tablets SlowestSlowest

13. Pharmacokinetics: AbsorptionPharmacokinetics: Absorption
•The rate at which a drug leaves its site of The rate at which a drug leaves its site of
administration, and the extent to which administration, and the extent to which
absorption occurs.absorption occurs.
–BioavailabilityBioavailability
–BioequivalentBioequivalent

14. Pharmacokinetics: AbsorptionPharmacokinetics: Absorption
Factors That Affect AbsorptionFactors That Affect Absorption
•Administration route of the drugAdministration route of the drug
•Food or fluids administered with the drugFood or fluids administered with the drug
•Dosage formulationDosage formulation
•Status of the absorptive surfaceStatus of the absorptive surface
•Rate of blood flow to the small intestineRate of blood flow to the small intestine
•Acidity of the stomachAcidity of the stomach
•Status of GI motilityStatus of GI motility

15. Pharmacokinetics: Absorption Pharmacokinetics: Absorption
RoutesRoutes
•A drug’s route of administration affects the rate A drug’s route of administration affects the rate
and extent of absorption of that drug.and extent of absorption of that drug.
–EnteralEnteral
–ParenteralParenteral
–TopicalTopical

16. Pharmacokinetics: AbsorptionPharmacokinetics: Absorption
Enteral RouteEnteral Route
•Drug is absorbed into the systemic circulation Drug is absorbed into the systemic circulation
through the oral or gastric mucosa, the small through the oral or gastric mucosa, the small
intestine, or rectum.intestine, or rectum.
–OralOral
–SublingualSublingual
–BuccalBuccal
–RectalRectal

17. First-Pass EffectFirst-Pass Effect
The metabolism of a drug and its passage The metabolism of a drug and its passage
from the liver into the circulation.from the liver into the circulation.
•A drug given via the oral route may be extensively A drug given via the oral route may be extensively
metabolized by the liver before reaching the systemic metabolized by the liver before reaching the systemic
circulation (high first-pass effect).circulation (high first-pass effect).
•The same drug—given IV—bypasses the liver, The same drug—given IV—bypasses the liver,
preventing the first-pass effect from taking place, and preventing the first-pass effect from taking place, and
more drug reaches the circulation.more drug reaches the circulation.

18. First-Pass EffectFirst-Pass Effect
•Routes that bypass the liver:Routes that bypass the liver:
–SublingualSublingual TransdermalTransdermal
–BuccalBuccal VaginalVaginal
–Rectal*Rectal* IntramuscularIntramuscular
–IntravenousIntravenous SubcutaneousSubcutaneous
–IntranasalIntranasal InhalationInhalation
*Rectal route undergoes a higher degree of first-*Rectal route undergoes a higher degree of first-
pass effects than the other routes listed.pass effects than the other routes listed.

19. Pharmacokinetics: AbsorptionPharmacokinetics: Absorption
Parenteral RouteParenteral Route
•Intravenous*Intravenous*
•IntramuscularIntramuscular
•SubcutaneousSubcutaneous
•IntradermalIntradermal
•IntrathecalIntrathecal
•IntraarticularIntraarticular
*Fastest delivery into the blood circulation*Fastest delivery into the blood circulation

20. Pharmacokinetics: AbsorptionPharmacokinetics: Absorption
Topical RouteTopical Route
•Skin (including transdermal patches)Skin (including transdermal patches)
•EyesEyes
•EarsEars
•NoseNose
•Lungs (inhalation)Lungs (inhalation)
•VaginaVagina

21. Pharmacokinetics: DistributionPharmacokinetics: Distribution
The transport of a drug in the body by the The transport of a drug in the body by the
bloodstream to its site of action.bloodstream to its site of action.
•Protein-bindingProtein-binding
•Water soluble vs. fat solubleWater soluble vs. fat soluble
•Blood-brain barrierBlood-brain barrier
•Areas of rapid distribution: heart, liver, Areas of rapid distribution: heart, liver,
kidneys, brainkidneys, brain
•Areas of slow distribution: muscle, skin, fatAreas of slow distribution: muscle, skin, fat

22. Pharmacokinetics: MetabolismPharmacokinetics: Metabolism
(also known as Biotransformation)(also known as Biotransformation)
The biologic transformation of a drug into The biologic transformation of a drug into
an inactive metabolite, a more soluble an inactive metabolite, a more soluble
compound, or a more potent metabolite.compound, or a more potent metabolite.
•Liver (main organ)Liver (main organ)
•KidneysKidneys
•LungsLungs
•PlasmaPlasma
•Intestinal mucosaIntestinal mucosa

23. Pharmacokinetics: MetabolismPharmacokinetics: Metabolism
Factors that decrease metabolism:Factors that decrease metabolism:
•Cardiovascular dysfunctionCardiovascular dysfunction
•Renal insufficiencyRenal insufficiency
•StarvationStarvation
•Obstructive jaundiceObstructive jaundice
•Slow acetylatorSlow acetylator
•Erythromycin or ketoconazole drug therapyErythromycin or ketoconazole drug therapy

24. Pharmacokinetics: MetabolismPharmacokinetics: Metabolism
Factors that increase metabolism:Factors that increase metabolism:
•Fast acetylatorFast acetylator
•BarbituratesBarbiturates
•Rifampin therapyRifampin therapy

25. Pharmacokinetics: MetabolismPharmacokinetics: Metabolism
Delayed drug metabolism results in:Delayed drug metabolism results in:
•Accumulation of drugsAccumulation of drugs
•Prolonged action of the effects of the drugsProlonged action of the effects of the drugs
Stimulating drug metabolism causes:Stimulating drug metabolism causes:
•Diminished pharmacologic effectsDiminished pharmacologic effects

26. Pharmacokinetics: ExcretionPharmacokinetics: Excretion
The elimination of drugs from the bodyThe elimination of drugs from the body
•Kidneys (main organ)Kidneys (main organ)
•LiverLiver
•BowelBowel
–Biliary excretionBiliary excretion
–Enterohepatic circulationEnterohepatic circulation

27. PharmacokineticsPharmacokinetics
Half-LifeHalf-Life
•The time it takes for one half of the original amount The time it takes for one half of the original amount
of a drug in the body to be removed.of a drug in the body to be removed.
•A measure of the rate at which drugs are removed A measure of the rate at which drugs are removed
from the body.from the body.

28. PharmacodynamicsPharmacodynamics
Drug actions:Drug actions:
•The cellular processes involved in the drug and The cellular processes involved in the drug and
cell interactioncell interaction
Drug effect:Drug effect:
•The physiologic reaction of the body to the drugThe physiologic reaction of the body to the drug

29. PharmacodynamicsPharmacodynamics
OnsetOnset
•The time it takes for the drug to elicit a The time it takes for the drug to elicit a
therapeutic responsetherapeutic response
PeakPeak
•The time it takes for a drug to reach its maximum The time it takes for a drug to reach its maximum
therapeutic responsetherapeutic response

DurationDuration
•The time a drug concentration is sufficient to elicitThe time a drug concentration is sufficient to elicit
a therapeutic responsea therapeutic response

30. Pharmacodynamics: Pharmacodynamics:
Mechanisms of ActionMechanisms of Action
The ways by which drugs can produce The ways by which drugs can produce
therapeutic effects:therapeutic effects:
•Once the drug is at the site of action, it can modify Once the drug is at the site of action, it can modify
the rate (increase or decrease) at which the cells or the rate (increase or decrease) at which the cells or
tissues function.tissues function.
•A drug cannot make a cell or tissue perform a A drug cannot make a cell or tissue perform a
function it was not designed to perform.function it was not designed to perform.

31. Pharmacodynamics: Pharmacodynamics:
Mechanisms of ActionMechanisms of Action
•Receptor interactionReceptor interaction
•Enzyme interactionEnzyme interaction
•Nonspecific interactionsNonspecific interactions

32. Pharmacotherapeutics: Pharmacotherapeutics:
Types of TherapiesTypes of Therapies
•Acute therapyAcute therapy
•Maintenance therapyMaintenance therapy
•Supplemental therapySupplemental therapy
•Palliative therapyPalliative therapy
•Supportive therapySupportive therapy
•Prophylactic therapyProphylactic therapy

33. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
•The effectiveness of the drug therapy must The effectiveness of the drug therapy must
be evaluated.be evaluated.
•One must be familiar with the drug’sOne must be familiar with the drug’s
•intended therapeutic action (beneficial)intended therapeutic action (beneficial)
•and the drug’s unintended but potential side and the drug’s unintended but potential side
effects (predictable, adverse drug reactions).effects (predictable, adverse drug reactions).

34. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
•Therapeutic indexTherapeutic index
•Drug concentrationDrug concentration
•Patient’s conditionPatient’s condition
•Tolerance and dependenceTolerance and dependence
•InteractionsInteractions
•Side effects/adverse drug effectsSide effects/adverse drug effects

35. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
Therapeutic IndexTherapeutic Index
•The ratio between a drug’s therapeutic benefits The ratio between a drug’s therapeutic benefits
and its toxic effectsand its toxic effects

36. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
ToleranceTolerance
•A decreasing response to repetitive drug dosesA decreasing response to repetitive drug doses

37. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
DependenceDependence
•A physiologic or psychological need for a drugA physiologic or psychological need for a drug

38. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
Interactions may occur with other drugs or foodInteractions may occur with other drugs or food
•Drug interactions: the alteration of action of Drug interactions: the alteration of action of
a drug by:a drug by:
–Other prescribed drugsOther prescribed drugs
–Over-the-counter medicationsOver-the-counter medications
–Herbal therapiesHerbal therapies

39. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
InteractionsInteractions
•Additive effectAdditive effect
•Synergistic effectSynergistic effect
•Antagonistic effectAntagonistic effect
•IncompatibilityIncompatibility

40. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
Medication MisadventuresMedication Misadventures
Adverse drug eventsAdverse drug events
•ALL are preventableALL are preventable
•Medication errors that result in patient harmMedication errors that result in patient harm
Adverse drug reactionsAdverse drug reactions
•Inherent, not preventable event occurring in the Inherent, not preventable event occurring in the
normal therapeutic use of a drugnormal therapeutic use of a drug
•Any reaction that is unexpected, undesirable, and Any reaction that is unexpected, undesirable, and
occurs at doses normally usedoccurs at doses normally used

41. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
Some adverse drug reactions are classified as Some adverse drug reactions are classified as
side effects.side effects.
•Expected, well-known reactions that result in little Expected, well-known reactions that result in little
or no change in patient managementor no change in patient management
•Predictable frequencyPredictable frequency
•The effect’s intensity and occurrence is related to The effect’s intensity and occurrence is related to
the size of the dosethe size of the dose

42. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
Adverse Drug ReactionAdverse Drug Reaction
An undesirable response to drug therapyAn undesirable response to drug therapy
•IdiosyncraticIdiosyncratic
•Hypersensitivity reactionsHypersensitivity reactions
•Drug interactionsDrug interactions

43. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
Iatrogenic ResponsesIatrogenic Responses
Unintentional adverse effects that are Unintentional adverse effects that are
treatment-inducedtreatment-induced
•DermatologicDermatologic
•Renal damageRenal damage
•Blood dyscrasiasBlood dyscrasias
•Hepatic toxicityHepatic toxicity

44. Pharmacotherapeutics: MonitoringPharmacotherapeutics: Monitoring
Other Drug-Related EffectsOther Drug-Related Effects
•TeratogenicTeratogenic
•MutagenicMutagenic
•CarcinogenicCarcinogenic