Drug Excretion Flashcards
The irreversible elimination of unchanged parent drugs or their metabolites from the body via various organs of excretion is called?
Drug excretion
Mention 7 organs of excretion
Skin
Hair
Breast
Kidneys
Intestine
Eyes
Tongue
Lungs
Examples of drugs excreted via the Large intestine are?
Vincristine, vancomycin
Examples of drugs excreted via the tongue are?
Phenytoin
Diazepam
Lithium
Caffeine
Theophylline
Examples of drugs excreted via the eyes?
Cytarabine
Variations in tear pH affects movements of unbound drugs between plasma and tear. T/F
True
Excretion by the tongue and eyes occur through what mode of molecule movements?
Passive diffusion
Examples of drugs/ substances excreted via the skin?
Antipyrine
Alcohol
Benzoic acid
Cocaine
Salicyclic acid
Lead
Mercury
Examples of drugs excreted via the breast?
Aspirin
Examples of drugs excreted via the hair?
Phenobarbital, methoxyphemenamine methamphetamine
Functional unit of the kidney?
What’s it made up of?
Nephron
Glomerulus and tubules
Renal excretion equals?
Glomerular filtration—tubular reabsorption +tubular secretion
Small molecules less that 30000 can be filtered such as water, sugar, salt, unbound drugs via pores at the base of the glomerulus
False! It’s less than 20000. The other statements are correct
How does tubular reabsorption occur?
Passive diffusion from tubules to peri tubular capillaries. Requires lipid solubility
Tubular secretion occurs how?
Carrier mediation, independent of size not protein binding
Tubular secretion excretes most drugs(80%). T/F?
Occurs where
T
Proximal and distal convoluted tubules
What happens to drugs with high molecular weight such as heparin, albumin
They are not excreted by GF
Water, soluble drugs and other soluble lipid substances are reabsorbed where and how?
Distal CT
by diffusion across renal tubule into the blood stream
Water and lipid soluble substances are readily excreted via the urine. T/F
F. Poorly excreted
The volume of plasma containing the amount of substance that is excreted by the kidney per unit time is known as ?
Renal clearance
Formulae for CLr?
CLr=Cu/Cp x Vu
What are the two types of half life?
Biological and plasma t1/2
What is biological t1/2
It is the time taken to lose half of its physiological, pharmacological or radioactive activity
What is plasma t1/2
The time taken for the plasma conc of a drug to be reduced to half
Plasma t1/2 administration on noradrenaline is how long?
2 mins
Plasma t1/2 administration on methadone is how long?
15hrs
Plasma t1/2 administration on fluoxetine is how long?
6 days
