general info

Question 1

Agonist

Answer 1

A chemical substance that binds to and activates certain receptors on cells, causing a biological response.

Oxycodone, morphine, heroin, fentanyl, methadone, and endorphins are all examples of opioid receptor agonists.

Question 2

Antagonist

Answer 2

A chemical substance that binds to and blocks the activation of certain receptors on cells, preventing a biological response.

Naloxone is an example of an opioid receptor antagonist

Question 3

Elderly Population General Rules

Answer 3

-longer elimination time generally from aging changes such as decreased liver enzymes —> lower doses are just as effective.

antipsychotics: risk of increased mortality (strokes) + also increased morbidity of worsening cognitive decline

Sedative-hypnotic drugs (esp. long-half-life benzos, can cause marked and prolonged cognitive impairment presenting as memory deficiencies.

Question 4

The therapeutic index (TI)

Answer 4

narrow therapeutic index (NTI) = small changes in dose could cause toxic results (lithium).
The larger the TI, the safer the drug
Ex- TI of 50 = need 50x the therapeutic dose to be in danger of OD

Question 5

DAT, SERT, NET

Answer 5

DAT (dopamine transporter), SERT (serotonin transporter), NET (norephinephrine transporter) - reuptake mechanism

Prozac blocks the activity of the SERT so that serotonin stays for longer period of time

Question 6

Pharmacodynamics

Answer 6

When a drug binds to its target, what is the effect?

effects –> drug interaction with receptors.

depends on:
(1) Different mechanisms at receptor (blocking vs increasing etc)
(2) Lipid solubility
affects how quickly the drug reaches it’s target
(3) Affinity for site of action
The higher the affinity, the lower dose you need

Question 7

PHARMACOKINETICS

Answer 7

ADME
How does a drug get to its target, and how much of it actually gets there?

ABSORPTION: How does a drug get into the bloodstream?
Route of administration (ROA)
-Oral, Rectal, Parentarel (Injection, Inhalation, Topical, Mucousal/Sublingual - gums, under tongue)

DISTRIBUTION
drug travels throughout the body until reaches its target (receptor)
Drugs that are lipid (fat) soluble get to their targets faster

METABOLISM
Breakdown of the drug by enzymes into metabolites (by-products or waste products) that no longer exert effects

ELIMINATION
most commonly in kidneys and liver

Question 8

First-pass metabolism

Answer 8

when drug-metabolizing enzymes in either GI tract or liver reduce the amount of drug that reaches the bloodstream

Question 9

Drugs taken orally are:

Answer 9

absorbed in either stomach or small intestine

Question 10

Cmax

Answer 10

highest level of concentration in blood

Question 11

Volume of distribution (Vd)

Answer 11

dose of the drug divided by concentration of the drug in plasma

Question 12

Half-life calculations

Answer 12

1 hl: 50% remaining
2 hl: 25% remaining
3 hl: 12.5% remaining
Steady-state can occur after 4 - 6 half-lives (independent of dosage)
6th half-life = 98.44% in the body

Question 13

The blood-brain barrier is most permeable to:

Answer 13

small, lipid-soluble molecules.

Question 14

Monoamines

Answer 14

Dopamine
Norepinephrine
Epinephrine
Serotonin

Question 15

monoamine theory of depression

Answer 15

depression is due to deficiency of monoamines

Antidepressants increase monoaminergic tone within hours, but therapeutic effects do not appear for weeks
→ believed it may change the sensitivity of receptors instead

Question 16

Monoamines TLDR

Answer 16

Dopamine - yes do that again!
Serotonin (5 - HT) - i like this. This is good (content, not motivated to chase)
NE - pay attention, something is happening!
E - Lets goooo!! muscular activation ie lets move our bodies

Question 17

Neurogenic theory of depression

Answer 17

The death of monoaminergic concentrations → less monoamines → less monoamine signaling → less ability to repair or create new neurons

Depression shares many cellular characteristics/markers with other neurodegenerative diseases (parkinsons, Alzheimers)
Antidepressant drugs increase the brain’s ability to protect neurons (both old and new)

Question 18

ED50

Answer 18

dose that produces the desired effect in 50% of pxts

Question 19

LD50

Answer 19

lethal dose for 50% of pxts