Pharm Pharacokinetics & Pharmacodynamics

UMSL School of Optometry Pharmacology Class (Dr. Dunden Lecture)

Increasing natural hormone

How can competitive inhibition be overcome?

inverse agonist (direct)

Agonist that produces less activity than baseline

drug C

Which drug(s) have the lowest potency?

increase

Drug binding the receptor may (increase/decrease) activity of receptor.

cranberry juice

Acidification by _______________ increases trapping of weak base.

sprays

Topical ophthalmic drug administration method used to administer mydriatic drops to closed eyes

ADME

What is the pneumonic to remember the varying pharmacokinetics of how the body acts on the medication?

1. Absorption
2. Distribution
3. Metabolism
4. Excretion

What are the 4 ways in which the body acts on medications?

absorption

Way in which the body acts on medication that involves entry of the drug into the body

distribution

Way in which the body acts on medication that involves the spreading of the drug throughout the body

metabolism

Way in which the body acts on medication that involves the transformation of a drug to a more active form & involves the modification of the drug for elimination

excretion

Way in which the body acts on medication that involves the removal of the drug via urine, feces, or bile

1. Enteral
2. Parenteral
3. Inhalation
4. Intrathecal/Intraventricular
5. Transdermal
6. Rectal
7. Topical

What are the 7 routes of drug administration?

enteral

Route of drug administration defined as either “by mouth” or “by using the GI tract”

1. Oral
2. Sublingual
3. Buccal

What are the 3 methods of enteral route drug administration?

oral

Enteral drug administration where the drug is swallowed by mouth

sublingual

Enteral drug administration where the drug is placed under the tongue

buccal

Enteral drug administration where the drug is placed between the cheek and gum

parenteral

What route of drug administration involves injection?

1. Intravenous (IV)
2. Intramuscular (IM)
3. Subcutaneous (SC)

What are the 3 parenteral types of injection drug administration?

intravenous (IV)

Which route of injection drug administration is very rapid & is completely absorbed?

intramuscular (IM)

What route of injection drug administration may either be rapidly or slowly absorbed?

subcutaneous (SC)

What route of injection drug administration is slower than IV absorption?

larger

A (smaller/larger) gauge indicates a smaller needle.

30-gauge

Ocular/intraocular injections are usually performed using what gauge of needle?

19-23 G

What gauge range of needle is used for intramuscular injections?

25-26 G

What gauge range of needle is used for subcutaneous injections?

25-28 G

What gauge range of needle is used for intravenous injections?

26-28G

What gauge range of needle is used for intradermal injections?

intrathecal/intraventricular

What route of drug administration involves direct administration into the brain?

transdermal

What route of drug administration involves patches being applied to the skin?

topical

What route of drug administration involves local application of medication, often on the skin?

inhalation

What route of drug administration involves oral or nasal drug administration, often with an inhaler?

topical

What route of drug administration is most used in optometry?

rectal

What route of drug administration is involved with suppository use?

oral

What is the safest & most common form of drug administration?

oral

What route of drug administration is susceptible to first pass metabolism (GI tract works on it)?

sublingual administration

What route of oral drug administration bypasses first pass metabolism?

intravenous (IV)

What route of injection drug administration involves direct insertion into the venous system, allowing full absorption into the vascular system?

intravenous (IV)

What route of injection drug administration has no absorption phase?

intramuscular (IM)

What route of injection drug administration has fast absorption, but has a slow, sustained release & works better for patient self administration?

intradermal (ID)

What route of injection drug administration is usually diagnostic & is involved with anesthetic drugs?

subcutaneous (SC)

What route of injection drug administration has a fast absorption & slow, sustained release & may cause local necrosis/inflammation?

subcutaneous (SC)

Insulin is a classic example of drug administration using what injection method?

transdermal

What route of drug administration is slow & sustained & bypasses first past metabolism?

transdermal

What route of drug administration is encompassed with motion sickness and nicotine patches?

inhalation

What route of drug administration has rapid absorption & may lead to systemic absorption?

inhalation

What route of drug administration is very effective for respiratory problems?

inhalation

What route of drug administration is the most addictive drug route?

topical

What route of drug administration has variable absorption, minimizes systemic absorption, and includes ophthalmic & otic?

epidural

What route of drug administration involves spinal injection?

ointment

Abbreviation “ung”

1. Topical
2. Periocular

What are the 2 main ophthalmic drug administration routes?

1. Subconjunctival
2. Sub-Tenon’s
3. Retrobulbar

What are the 3 types of periocular administration of drugs?

1. Sub-conjunctival
2. Sub-Tenon’s capsule
3. Retrobulbar

Identify the labeled methods of periocular drug administration in the figure.

RPE & photoreceptors

Between what 2 layers of the retina is a subretinal injection administered?

topical

What method of ophthalmic drug administration is convenient & has poor systemic absorption?

1. Solutions
2. Suspensions
3. Emulsions
4. Ointments
5. Gels
6. Lid scrubs
7. Sprays

What are the 7 types of topical ophthalmic drug administration methods?

suspensions

Topical ophthalmic drug administration that must be shaken before use and has a longer contact time

solutions

Topical ophthalmic drug administration method that has inconsistent deliver, short contact time, and risk of contamination

emulsions

Topical ophthalmic drug administration method that is not shaken and has a longer contact time

ointments

Topical ophthalmic drug administration method that dissolves quickly, has longer contact time, and an increased chance of blurred vision

Gels

Topical ophthalmic drug administration method that increases contact time but causes less bluirred vision

lid scrubs

Topical ophthalmic drug administration commonly used to treat eye lid infections

Gel/Ointments; solutions

What topical ophthalmic drug administration method has the greatest approximate contact time? Least contact time?

1. Paper strips
2. Cotton pledgets

What are 2 examples of solid delivery topical ophthalmic drug devices?

adenoviral infections

What type of infections are often treated with betadine flushing of the eye?

subconjunctival injections

What type of periocular ophthalmic drug administration has a high local concentration and is useful for cornea infections?

sub-Tenon’s injection

What periocular ophthalmic drug administration method has the greatest risk of causing glove perforation?

retrobulbar injection

What method of periocular drug administration is used for anesthetic delivery for ocular surgery and is contained within the muscle & fat cone?

peribulbar injections

What method of periocular drug administration is used for local injections of anesthetic around teh globe, is safer, and is injected outside the muscle & fat cone?

1. Intracameral
2. Intravitreal
3. Subretinal

What are the 3 types of intraocular ophthalmic drug administration?

intracameral injection

What intraocular ophthalmic drug administration route is injected directly into the anterior chamber and is used in cataract & glaucoma surgeries?

intravitreal injection

What intraocular ophthalmic drug administration route is injected directly into the vitreous body, is used for endophthalmitis (antibiotics), neovascularization treatments, macular edema treatments, and severe viral infection treatments?

subretinal injection

What intraocular ophthalmic drug administration route is more targeted than intravitreal injections & has a greater risk of complications?

1. Passive diffusion
2. Facilitated diffusion
3. Active transport
4. Endocytosis & exocytosis

What are the 4 mechanisms of drug absorption?

passive diffusion

What mechanism of drug absorption is concentration-based & will enter either through a channel or pore or by being lipid soluble?

facilitated diffusion

What mechanism of drug absorption moves with the concentration gradient and is drug/shape specific?

active transport

What mechanism of drug absorption requires ATP & moves against the concentration gradient?

endocytosis & exocytosis

What mechanism of drug absorption involves larger molecules and surrounded by plasma membrane?

1. pH
2. Blood flow
3. Total surface area
4. Contact time
5. P-glycoprotein

What 5 factors influence drug absorption?

a. Weak Acids

What pH is more effective with pH
a. Weak Acid

b. Weak Base

b. Weak Base

What pH is more effective with pH>pKa (deprotonated) drugs?

a. Weak Acid

b. Weak Base

uncharged

Drugs absorb best when (charged/uncharged).

Increased

(Increased/Decreased) blood flow increases drug absorption.

Increased

(Increased/Decreased) contact time results in greater absorption.

Gel/ointment

Of these options, which have the greatest contact time?

a. Solutions

b. Suspension/emulsion

c. Gel/ointment

P-glycoprotein

What factor influencing drug absorption forms a pore that increases absorption of some drugs?

Bioavailability

Amount of uncharged drug in the body

IV drugs

What type of drugs have 100% bioavailability?

liver

Where in the body are oral drugs metabolized?

1. First pass hepatic metabolism
2. Solubility of drug
3. Chemical stability
4. Drug formulation

What are the 4 influencing factors of bioavailability?

bioequivalent

Drugs are considered _______________ if they take the same amount of time to reach peak concentration.

therapeutically equivalent

Generic drugs are considered to be _________ ____________ drugs.

90

Generic drugs have a pKa within the ____% confidence interval of the name brand.

1. Blood flow
2. Capillary permeability
3. Binding of drugs to plasma proteins
4. Lipophilicity

What 4 factors influence drug distribution?

Lipid

(Water/Lipid) soluble drugs can cross cell membranes.

improves

Binding of drugs to plasma proteins (improves/impairs) transport.

1. Continuous
2. Fenestrated
3. Discontinuous

What are the 3 types of capillary permeability?

discontinuous

What type of capillary permeability has the best medication distribution?