Page 30 - Pharmacology Mnemonics and Short Notes

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Drug Excretion and elimination

Drugs are eliminated from the body
either unchanged or as metabolites.
 Kidney is the major organ for drug

excretion
• Kidney

 Acidic urine  Excretion of basic drugs
 Alkaline urine  excretion of acidic Drugs
First order kinetics
A constant fraction of drug is eliminated per

unit of time.
When drug concentration is high, rate of disappearance is high.

Zero order kinetics

Rate of elimination is constant and is independent of concentration

Example  Alcohol

•Other routs of drug excretion include: Bile, Stool, Stomach (Morphine),
Saliva (Iodides), Sweat (rifampicin), Milk (amphetamine) and Lungs

(nitrous oxide).

Other pharmacokinetic Properties
Clearance

Contents Volume of blood or plasma that can be freed of a drug in a specific time is
called clearance

Pharmacology Mnemonics and Short Notes By Muhammad Ramzan Ul Rehman