Pharmacology Flashcards
What are the goals of Phase I to IV studies?
What are the approximate numbers of such studies?
I - safety and dose finding (n=20)
II - safety and preliminary efficacy (n=100)
III - safety and mostly efficacy (n=500)
IV - post-marketing surveillance / AEs (n=1000s)
What is the most common toxic effect of quinine (anti-malarial drug)?
Blindess - directly affects optic nerve and also causes vasoconstriction and spasm of retinal artery.
Tinnitus/Deafness - directly affect auditory nerve
What are 4 drugs that induce CYP3A4?
SCRaP inducers:
St John’t Wort
Carbamazepine
Rifampicin
Phenytoin
For the 2 following substances, which causes an increase vs a decrease in INR?
What is the mechanism?
- Cranberry juice
- St John’s Wort
- Cranberry juice inhibits cytochrome p450 and therefore INCREASES INR
- St John’s Wort induces cytochrome p450 and therefore DECREASES INR
Give 3 drugs that cause gingival hyperplasia
Cyclosporin
Nifedipine
Pheytoin
With gingival hyperplasia you Can Not Pout (CNP)!
Which of the following pharmacokinetic parameters has the greatest effect on LOADING DOSE?
- Clearance
- Half-life
- Volume of distribution
- Protein binding
- Lean body mass
- Volume of distribution
Phenytoin has a variable half-life at therapeutic doses, why is this?
It follows zero-order elimination kinetics
With which genotype will Carbamazepine trigger Stevens-Johnson syndrome or toxic epidermal necrolysis?
HLA-B*1502
With which genotype will Allopurinol trigger Stevens-Johnson syndrome or toxic epidermal necrolysis?
HLA-B*5801 (especially asians)
T/F: normograms should be used for measuring drug levels in patients with renal impairment.
False - normograms are for healthy controls.
What is the formula for calculating Cl, given Vd and t1/2?
Cl = [Vd x 0.69] / t 1/2
What is good rough estimate for the breakthrough dose for an opioid analgesia?
1/6 of the daily dose (5-20%)
