exam graded A+ 2024/2025
What is the pKa of a drug? - ✔️✔️The pH at which the drug is 50% ionized and 50% non-
iodized (aka equal deprotonated and protonated forms of the drug)
For drugs to be absorbed, do we want them charged or uncharged? - ✔️✔️Uncharged
What is the pH of the stomach vs. the small intestine? - ✔️✔️Stomach: pH around 1
Small intestine: neutral pH around 7
You develop a drug and decide to name it BLACKPINK. BLACKPINK has a pKa of 3.
Would it be better absorbed in the stomach or small intestine? - ✔️✔️It would be better
absorbed in the stomach because the stomach has a pKa of 1 and so we would have
100X more HA than A-. Remember that non-charged drugs are better absorbed.
You develop a drug and decide to name it LOONA. LOONA has a pKa of 10 (because
the LOONA girls are 10/10). Is it better absorbed in the stomach or small intestine? -
✔️✔️It is better absorbed in the small intestine because more of it will be the in
uncharged state.
Note: bases higher than the environment pH still have more charged compounds than
uncharged
What percentage of intravenously administered drugs are bioavailable? - ✔️✔️100%
baby
What is the difference between a LOW volume of distribution and a HIGH volume of
distribution? - ✔️✔️Low Vd: drug is highly contained in the vascular compartment
High Vd: drug is not highly contained in the vascular compartment lol
Describe the difference between drugs with a Vd of around 42 and those with Vd higher
than 42 - ✔️✔️~42: suggests the drug reaches the intracellular fluid
Greater than 42: suggests the drug is concentrated intracellularly
What is the first pass effect? - ✔️✔️After oral administration, many drugs are absorbed
intact from the small intestine and transported first via the portal system to the liver,
where they undergo extensive metabolism, therefore usually decreasing the
bioavailability of certain oral medications.
You can try sublingual or up the bum to reduce this effect
, Describe the difference between zero order kinetics and first order kinetics when it
comes to elimination - ✔️✔️Zero order kinetics: linear (ex. loss of 5 mmol/L every hour)
First order kinetics: half life (ex. 50% of the drug remaining after 1 hour)
A number of protein pumps exist in this section of the nephron to help eliminate drugs -
✔️✔️Proximal tubule
This site of the nephron allows passive transfer of drugs that are lipid soluble - ✔️✔️Distal
tubule
When it comes to potency, what is the ED50? - ✔️✔️The concentration of the drug that
produces a response in 50% of individuals
When it comes to potency, describe what the dissociation constant (Kd) is. - ✔️✔️The
dissociation constant (Kd) is the drug concentration required to saturate 50% of its
receptors
The lower the Kd, the greater the drug's affinity to the receptor
(Low Kd means less drug is required to fill receptors and therefore means more affinity)
What is one way you can overcome a competitive inhibitor? - ✔️✔️Add more of the drug
Does a super safe drug have a low or high therapeutic index? - ✔️✔️Higher than a kite
The certain safety factor is a ratio of what? - ✔️✔️Ratio of LD1 and ED99 (LD1/ED99)
-Higher CSF = safer drug!
Name some changes that may affect drug responses in the elderly - ✔️✔️1. Less albumin
2. Decreased lean body mass
3. Liver weight decreases
4. Changes to CYP450
5. Kidney function decreases (lower GFR)
Name some changes that may affect drug responses in pregnant women - ✔️✔️1.
Concentration of albumin reduced due to increased total blood volume
2. Cardiac output increased resulting in increased renal blood flow
3. Placental barrier may heavily metabolize some drugs (ex. prednisone)
This drug is a lipid lowering drug and is the only drug approved for primary prevention of
cardiovascular disease - ✔️✔️Atorvastatin
Explain how statins inhibit the cholesterol synthesis pathway - ✔️✔️The rate limiting step
of cholesterol synthesis occurs when HMG CoA reductase converts HMG CoA to