General Principles Of Pharmacology Flashcards
What is the nature of a drug?
In general drugs are chemical substances that bind to the receptors of agonist and antagonist regulatory molecules of the biological systems.
What are chemical antagonists ?
Chemical antagonists are drugs that interact directly with other drugs.
What are osmotic agents?
Osmotic agents are drugs that interact exclusively with water molecules.
What are the requirements for a drug to bind to it’s receptors?
The drug molecule must have the appropriate size, electrical charge,shape and atomic composition.
What is the molecular weight limit of most drugs?
Upper = 1000 MW
Lower= 100 MW
What are the three chemical bonds that mediate drug-receptor interactions ?
The covalent, electrostatic, and hydrophobic forces.
How does aspirin ( acetylsalicylic acid )block platelet aggregation?
It binds to the enzyme target cyclooxygenase in platelets to prevent platelet aggregation by covalent bonding.
How long the platelet aggregation blocking effect of aspirin last after free acetylsalicylic acid disappear from the blood stream?
15 min .
The weak hydrophobic bonds are important.why?
Hydrophobic bonds can prevent potential interaction of highly lipid soluble drugs with the lipids of cell membranes and with lipophilic walls of receptors
Drugs that bind to their receptors through weak bonds are more selective and specific than drugs that bind through strong bonds. Why ?
This is because weak bonds require very precise fit of the drug to it’s receptors. This kind of Bonding is the choice of manufacturing highly selective short acting drugs.
