Applied Therapeutics/Fundamentals Of Pharmacology

Question 1

How many half lives does it take for 97% of drug to be eliminated?

Answer 1

5 half lives

Question 2

Increasing the concentration of an agonist increases its effect when in competition with a competitive antagonist. True/false?

Answer 2

True

Question 3

Name 5 drugs that require extra care when switching between liquid and tablet/capsule formulations.

Answer 3

Alfacalcidol
Carbamazepine
Chloral hydrate
Citalopram
Clomethiazole
Clozapine
Co-amoxiclav
Digoxin
Emtricitabine
Fusidic acid
Itraconazole
Lithium
Mebeverine
Mercaptopurine
Metronidazole
Mycophenolate
Phenytoin
Posaconazole
Raltegravir
Selegiline
Sirolomus
Tenofovir disoproxil
Tipranavir
Valproate
Vardenafil
Vitamin E and vitamin K

Question 4

What is the relationship between dose rate, clearance (Cl) and plasma concentration (Cp) in terms of an equation?

Answer 4

Dose rate = Cl * Cp
Or
Cp = dose rate / Cl

Question 5

What is the relationship between dose, volume of distribution (Vd) and plasma concentration (Cp)?

Answer 5

Vd = dose / Cp

Question 6

Which two variables is half life dependent on?

Answer 6

Clearance and volume of distribution

Question 7

Which body weight should used when calculating a gentamicin dose?

Answer 7

Use CBW

Ideal body weight (IBW) = 50 + (2.3 x no. of inches over 5 feet)
(NB use 45.4 if female)

Corrected body weight (CBW) = IBW + 0.4(ABW-IBW)

[ABW is Actual body weight]