1

Chapter 3Chapter 3

Methods of Drug Delivery

2

Delivery of DrugsDelivery of Drugs

Enteral – digestive tractParenteral – major route; Given into the

cardiovascular circulationTopical – by application onto the skin or

associated membranes

3

Process of Drug DeliveryProcess of Drug Delivery

Drug Administration Phase – depends on form of med, speed medication action is needed, desired location

Enteral Parenteral Topical

4

Process of Drug DeliveryProcess of Drug Delivery

Pharmacokinetic Phase – movement of drugs throughout the body to various targets

Absorption Distribution Metabolism Excretion

5

Process of Drug DeliveryProcess of Drug Delivery

Pharmacodynamic Phase – drugs produce a change or an effect at a specific target (receptor)

Efficacy Potency

6

Physical PropertiesPhysical Properties

Influence how medications enter and move throughout the body

7

Physical PropertiesPhysical Properties

Solids – most effective via a body opening, need to dissolve first to become active, which slows the process

8

Physical PropertiesPhysical Properties

Liquids- move quicker through the body but need to penetrate the cellular membrane, viscosity can make it more difficult if it is higher, solubility the ability to dissolve will affect how easily it passes across the membrane

9

Physical PropertiesPhysical Properties

Hydrophobic- dissolve in lipids, work better penetrating body membranes

10

Physical PropertiesPhysical Properties

Hydrophilic – dissolve in water, work better in the bloodstream

11

Physical PropertiesPhysical Properties

Gas Fast absorption, moves quicker to target

area and action is in seconds

12

Oral RouteOral Route

By mouth Can be chewed, swallowed, or dissolved in

the mouthTablets, capsules, powders, solutions,

suspensionsDissolution delays the onset of action, water

is needed or may be taken with food

13

SublingualSublingual

Absorbed quickly into the bloodstreamAvoid the first- pass effect –intestinal

absorption into the portal circulation to the liver to be metabolized by the liver

14

RectalRectal

Use with unconscious patients, patients with N/V, infants not able to swallow pills

Rapid onset of action due to blood supply

15

Injection Into the Blood Injection Into the Blood VesselsVessels

IVBolusInfusionBypasses destructive enzymes of GI tract

and the liver

Fluid overload, infection

16

InjectionsInjections

Intradermal dermis easily absorbed

Subcutaneous hypodermis Intramuscular muscles faster onset of action

17

InjectionsInjections

Advantage IM and subcutaneousConcentration of drug is predictableConfined to a precise locationMay be given to unconscious patients and

childrenDisadvantage IM and subcutaneousPain, swelling, tissue damage, infection

18

InjectionsInjections

Intrathecal directly in spinal subarachnoid space(dorsal spine spinal cavity beneath a sheath surrounding the spinal cord called the anrachnoid mater) spinal anesthetics or medications that might enter the cerebral spinal fluid

19

InjectionsInjections

Epidural directly into a space overlying the dura mater (most superficial layer of that protects the CNS)

20

InjectionsInjections

Intraperitoneal directly into the abdominal cavity

21

InjectionsInjections

Into the joint spaces (analgesics and anti- inflammatory drugs)

22

TopicalTopical

Skin EyesEars Nasal membranes Reproductive openingsEffect is systemic or local

23

Transmucosal DrugsTransmucosal Drugs

Cross membrane liningRespiratoryReproductive tractsEffect: systemic or localForms: suppositories, sprays, mists, foams,

aerosols, volatile agentsExamples: asthma, vaginal infections

24

Ears and EyesEars and Eyes

Eyes Effect: to lubricate, prevent inflammation or

treat infections of the corneaForms: ointments, salves, or dropsEarsEffect: to treat infections, cerumen buildupForms: drops ( need to penetrate the ear

canal and middle ear to be effective)

25

Client TeachingClient Teaching

Oral: take with water or food to reduce nausea

Establish a routineFollow dosing times, do not play catch upStore medication in a dry safe placeDiscard outdated medicationsTake medications with calibrated insert

provided

26

EndEnd