Chapter 9- Acids & Bases

Question 1

Acid

Answer 1

A chemical substance that donates a H+ to a solution

Question 2

Base

Answer 2

Accepts H+ in a solution

Question 3

Weak acid/base vs strong acid/base

Answer 3

Weak- partially dissociates when dissolved in water (less effect on pH)

Strong- completely 100% dissociates when dissolved in water (big impact on pH)

Question 4

Weak acids

Answer 4

Thiopental
Barbiturates
Phenobarbital 
Methotrexate
TCAs
Aspirin

Question 5

Weak bases

Answer 5

Local anesthetics:
Lidocaine
Amphetamine
Morphine

Question 6

Ionized form

Answer 6

Water soluble (lipid insoluble)

Cannot cross cell membrane

Question 7

Non-ionized form

Answer 7

Lipid soluble (water insoluble)

Can cross cell membrane

Question 8

pKa

Answer 8

The pH at which 50% of drug is ionized and 50% is non-ionized (1:1)

Question 9

When pH is less than pKa…

Answer 9

Increased HA (non-ionized form of acid) and BH+ (ionized form of base) predominate

Question 10

When pH is greater than pKa…

Answer 10

Increased A- (ionized for of acid) and B (non-ionized form of base) predominate

Question 11

Acidic drug + acidic media =?

Answer 11

Non-ionized form (lipid soluble)

Question 12

Acidic drug + basic media =?

Answer 12

Ionized form (water soluble)

Question 13

Basic drug + basic media =?

Answer 13

Non-ionized form (lipid soluble)

Question 14

Basic drug + acidic media =?

Answer 14

Ionized form (water soluble)

Question 15

Weak acid is stored in what?

Answer 15

High pH solution

Ionized form will not precipitate

Question 16

Weak base is mixed and stored in what?

Answer 16

Low pH solution

Ionized form will not precipitate

Question 17

State of equilibrium

Answer 17

When there is balance b/w reactants and products

Question 18

Le Châtelier’s Principle

Law of Equilibrium

Answer 18

When a system in a state of dynamic equilibrium is disturbed, it will react to re-establish the equilibrium condition

(Compensation)

Question 19

“Ion trapping” drug elimination

Answer 19

Ionized species get trapped and cannot transport back to blood ➡️
Excreted in urine

Question 20

Treatment of aspirin overdose

Answer 20

Alkalinize the urine (increasing urinary pH) with NaHCO3

Ionized form will predominate and excrete in urine

Question 21

Most important ECF buffer

Answer 21

Bicarbonate

Question 22

Important renal tubular buffers?

Answer 22

Phosphate (HPO4-)

Ammonia (NH3 + H+= NH4+)

Question 23

Important intracellular buffers

Answer 23

Proteins

60-70% of buffering is done in the cells

Question 24

Treatment of amphetamine overdose

Answer 24

Acidify urine with ammonium chloride (NH4Cl)

Question 25

How do you get rid of NH3 in hepatic encephalopathy

Answer 25

I’m cirrhosis, lover unable to metabolize NH3 (base)

Give lactulose, will convert into lactic acid

Acid+base= ionized form (NH4+)
Cannot reabsorb so gets excreted from gut