Basic Phamacology ( chap 1 )

Question 1

What is a drug

Answer 1

• substance that alters physical state

- chem+empiracle+generic+trade name

Question 2

dose description

Answer 2

• mg/kg
• dose response curve ( Effective Dose 50%/Lethal Dosd 50%)
• Therapeutic index(TI) = LD50/ED50
• -> larger TI = safer drug

Question 3

Potency

Answer 3

• comparing two drugs w/ same effects but different ED50

- lower ED50= higher potency

Question 4

Effectiveness

Answer 4

dif in max effect between two drugs at any dose

Question 5

Primary vs . side effects

Answer 5

-effect for which the drug was taken
vs
-additional effect

Question 6

Drug interactions :

• type
• use

Answer 6

• antagonism(shirt curve right)
  additive effect(shift left)
  superadditive/potentiation( effect of A shifts B DRC further then predicted)

Question 7

Pharmacokinetics

Answer 7

way the body metabolizes, excretes and move drugs

Question 8

Routes of administration (parenteral sites)

Answer 8

• parenteral (skin)
• Vehicle (physiological saline)
• Subcutaneous (rely on absorbance below the skin and rate to reach b.s.)
• Intramuscular (rely on absorbance in muscle and rate to reach blood stream)
• Intraperitoneal (rely on absorbance in body cavity to reach b.s.)
• Intravenous (directly through blood stream)

Question 9

Absorption from:

• parenteral sites
• Transdermal site

Answer 9

• capillary-> heart-> artery -> capillary-> vein
• single layer of cells w/ pores(nutrients, waste, drugs pass freely)
• more in peritoneum>muscle>skin
• diffusion: movement from [higher] to [lower]
• depot injection: last 4 weeks (antipsycholics : [high] in OIL often intramusclar )
• Epidermis

Question 10

Inhalation of Gases:

-routes and processes

Answer 10

Lungs:
-drug absorption /higher efficient + diffusion is bilateral + fast (bypass liver metabolism) == delivered with precision
- smoke+solid are dissolved in moist lungs and unidirectional== metabolized
Intranasal:
-nasal+lung+ digestive absorption

Question 11

Oral absorption

Answer 11

• Peroral

- Suppository

Question 12

Processing of Drugs

Answer 12

1. ) Absorption (rate of dissolution: blood flow+Surface Area +Lipid solubility {higher LS=higher absorbance} @ admin site)
2. )Distribution (pH partitioning: drug that ionize in blood and NOT @ admin site= increase absorbance)
3. )Metabolism:(biotransformation) enzymatic alterations of drug structure
4. )Excretion: removal of drug from body
   * ** increase dissolution= increased absorption= increased effect

Question 13

Crossing the Phospholipid bilayer

Answer 13

1. ) membrane channel/pores (small molec)
2. ) Transport proteins ( selective carriers)
3. ) Direct diffusion (‘like’ dissolves ‘ like’)

Question 14

pH dependent ionization

Answer 14

• acid+acid solution => LS
  acid + alkaline solution => Ionize
• base +acidic solution=> Ionize
  base+alkaline solution=> LS

Question 15

Digestive System

Answer 15

• intestine wall lipid bilayer (pH=3.5)
• dependent on LS + oil partition coefficient
• -> pKa rate of movement across membrane

Question 16

pKa

Answer 16

pH @which 50% ionized and 50% LS where drug can diffuse through membrane

Question 17

pH partitioning/ Ion trapping

Answer 17

• drug accumulates on ionization side of membrane

- pH dependent ionization predict at which environment/pH the drug will accumulate

Question 18

Obstacles for drug absorption

Answer 18

• BBB: made of PB +influx pumps(deliver nutrients from capillarity to brain and vice versa {OATP2})+efflux(mutli drug resis. pump–> move drugs OUT){lipisomes overload and modify for OATP2}
• Lipid Bilayer(PB): permiable to small or LS molec

Question 19

Distribution routes

Answer 19

-Liver: (major metabolic enzyme)
–> Alcohol dehydrogenase(remove H+ and increases with the amount of consumption = enzyme induction)=into metabolites(increase usefulness or decrease toxitiy of material==> increase ionization)
=>detoxification
-Kidney:(filters everything out then reabsorbs)
–> Nephron (long tubes: mil per kidney)+ Bowman’s Capsule(glomerulus which are clumps of capillaries)
–> diffusion from blood to glomerulus then back if needed
–> Passive or Active Transport back into blood, if no the excreted

Question 20

Disulfiram

Answer 20

absorbed through digestive track and last 2 weeks

-in combination with alcohol and negative reaction (detour alcholism )

Question 21

First-Pass Metabolism

Answer 21

• rate of excretion/half life
• decrease effectiveness of kidney with decreased [drug]
• negative exponential curve ( % / min )

Question 22

Factors that alter drug metabolism

Answer 22

= stimulants of enzyme system

=depressants of enzyme system

Question 23

Therapeutic Window

Answer 23

• below toxic level+ above therapeutic level

- optimal dosage for ideal effecets