Pharmacology Lecture (Med Sci, Spring 06)

Front 1

Definition of a drug

Back 1

any chemical agent that affects a physiologic process

Front 2

Routes of administration

Back 2

ENTERAL (using GI Tract)
- Oral (PO)
- Sublingual (SL)
- Rectal (PR)

PARENTERAL (NOT using GI tract)
- Intravenous (IV)
- Intramuscular (IM)
- Subcutaneous (SC)
- Topical
- Transdermal
- Inhalation

Front 3

Most important organ for drug excretion

Back 3

Kidneys

Front 4

Most common site for drug metabolism

Back 4

LIVER. (may also occur in kidneys, lungs, GI tract)

- Will convert an active form --> inactive form to allow its elimination.

- Will convert a "pro-drug" to its active form.

Front 5

Definition of pharmacokinetics

Back 5

the rate at which a drug is absorbed and eliminated.

Front 6

First Order Kinetics

Back 6

Drug is eliminated at a rate proportional to its concentration.

** most common rate of elimination**

Front 7

Considerations for dosing

Back 7

Goal = therapeutic dose that avoids side effects and toxicity.

- It takes 4-5 half-lives to achieve a steady-state situation of a drug concentration in first-order kinetics.

Onset = amount of time it takes a drug to start working.

Duration = length of time a drug is therapeutic.

Front 8

EC 50

Back 8

"effective concentration" - concentration of drug which induces a therapeutic effect in 50% of subjects to which it is administered.

Front 9

LD 50

Back 9

"lethal dose" -
concentration of a drug that is lethal in 50% of the subjects to which it is administered.

Front 10

Therapeutic index

Back 10

LD 50 / EC 50

Front 11

Margin of Safety

Back 11

Margin between therapeutic and lethal doses of a drug.

Front 12

Agonist

Back 12

drugs which alter the physiology of a cell by binding to its receptors.

response usually dependent on the percentage of receptors bound.

Front 13

Antagonist

Back 13

inhibits or blocks response caused by an agonist.

Competitive antagonist = competes with agonist for receptors.

Noncompetitive antagonist = binds to another site than the agonist, but causes a conformational change that prevents the agonist from binding.

Front 14

Tolerance

Back 14

= decreased response to a drug; must increase dose to acheive same effect.

- metabolic (increased rate)
- cellular (decreased # receptors)
- behavioral

Front 15

Dependence

Back 15

- patient needs drug to "function normally"
- cessation of drug will cause withdrawl symptoms
- may be physical or psychological

Front 16

Drug interaction equations

Back 16

Additive response: 1+1=2
Synergist response: 1+1=3
Potentiation response: 1+0=2
Antagonism response: 1+1=0

Front 17

NSAID v Acetaminophen

Back 17

NSAID = analgesic, antipyretic, anti-inflammatory,

Acetaminophen = analgesic, antipyretic, NO EFFECT ON INFLAMMATION.

Front 18

NSAIDs

Back 18

"Non-steroidal anti-inflammatory drugs."

- most widely prescribed class of medication in the US

- works by inhibiting cyclo-oxygenase activity in prostoglandin cascade.

Front 19

COX-2 Inhibitors

Back 19

(Celebrex, Vioxx, Bextra)
- Minimal GI side effects
- no platelet effects
- too much (too long/dose too high) leads to heart attacks.

Front 20

NSAID side effects

Back 20

- Gastric ulcers/distress (MOST COMMON)
- Platelet inhibition/bleeding
- Renal failure
- Hepatic dysfunction
- Hypertension
- peripheral edema
- tinnitus
- asthma exacerbations
- Extra risk for elderly, children, pregnant women.

Front 21

COX/NSAID Safety (2 points)

Back 21

1. Coxibs and nonselective NSAIDS are associated with increased hypertension and peripheral edema.

2. Coxibs provide better safety to GI tract than non-selective NSAIDs.
- but they're not any stronger.
- (?) destabilize vascular endothelium
- platelet effects

Front 22

Actions of Narcotics

Back 22

Narcotics mimic the effects of endogenous opioids: endorphin, enkephalin, dynorfins.

1. Pain relief
2. Euphoria
3. Anti-tussive
4. Decrease intestinal motility

Front 23

Narcotic Side Effects

Back 23

- Respiratory Depression
- Constipation
- Sedation
- Nausea/vomiting
- Confusion
- Hypotension
- Addiction/abuse
- Cholestasis (gall bladder attack)

Front 24

Mechanism of Sedatives/Hypnotics

Back 24

Enhances GABA's inhibitory action
- (GABA allows Cl- to enter, hyperpolarizing cell, making it harder to depolarize.)

Front 25

Sedative/Hypnotic Side Effects

Back 25

- Drowsiness
- Confusion
- Dysarthria (slow speech)
- Ataxia
- Memory loss (short term)
- Paradoxical stimulation
- Respiratory depression
- Behavioral disinhibition
- Addiction/abuse potential

Front 26

3 Principles of Homepathy

Back 26

1. Law of Similars: Substance may have opposite effects on health in different people.

2. Principle of Minimum Dose: By diluting a substance, its curative properties are enhanced and its side effects minimized.

3. Prescribing for the individual should take into account condition AND patient's temperament, personality, and emotional/psychological respose.

Front 27

6 Basic Philosophies of Naturopathy

Back 27

1. Body has an ability to heal itself.
2. Treat the whole person.
3. Do no harm.
4. Treat cause, not symptoms.
5. Prevention is best cure.
6. Physician as teacher.

Front 28

Creatine

Back 28

- Naturally occuring nitrogen compound (3 amino acid)
- Primarily located in skeletal muscle
- Provides phosphate group to ADP to make ATP

- Loading dose is expensive for the amount of drug that is just excreted.
- Naturally synthesized in liver (2 grams daily); stored in liver as creatine phosphate.

- May be helpful in exercises that require short or repeated bouts of energy expenditure.
- No utility in long-distance events.
- Increased muscle mass and strength
- Delays fatigue

Front 29

Creatine Side Effects

Back 29

- Weight gain from water retention.
- Muscle cramps.

- Renal injury from prolonged use in dehydrated state.

Front 30

Androstenedione

Back 30

= hormone produced by adrenals which is a precursor to estrogen and testosterone.

- anabolic steroid-like effect.
- Studies have shown oral andro does not increase seurm testosterone levels or enhance musculoskeletal adaptations.
- Notable increase in estradiol levels.

Front 31

Androstenedione Side Effects

Back 31

- Impotence
- Testicular Atrophy
- Elevated cholesterol levels (increased risk of CAD)
- Acne
- Prostatic hypertrophy

Front 32

Glucosamine/Chondroitin Sulfate

Back 32

- Promotes "joint health."
- Basic building blocks for joint cap cartilage
- mild antiinflammatory effect

- expensive, often not covered by insurance
- takes 3 months to see an effect
- wide variability in dosing and availability from mfg to mfg.

Front 33

Glucosamine/Chondroitin Sulfate Side Effects

Back 33

- Insulin resistance
- dyspepsia
- nausea/vomiting
- edema
- anorexia
- headache
- tachycardia

Front 34

Ephedra

Back 34

- Common supplement in weight reduction and energy pills
- medically used as treatment for asthma
- Similar to ingredients in OTC cold/sinus medication

Front 35

Ephedra Side Effects

Back 35

- Increases heart rate
- Constricts blood vessels
- Increases blood pressure
- Decreases ability of body to dissipate heat
- Banned in many sports organizations
- First supplement banned by FDA in recent era