Pharmacology Flashcards
Define E50
The concentration of a drug that gives half the maximal response
Define Emax (Efficacy)
The maximum response of a drug achievable
Why might a certain drug be ineffective? (4)
- Dose too low
- Administration failure
- Destroyed in the stomach
- Tachyphylaxis
Why is drug monitoring and combined treatments important in some conditions? (5)
- May be side effects
- Rarely a standard dose, may be given too little and needs more
- Regular blood chemistry
- May need weighing
- May need another investigation
State the non-specific mechanisms by which heart failure can be managed and the drugs that can be used (5)
- Increase contractility - Positive inotropes
- Removal of oedema - diuretics
- Slow down heart rate, remove dysrhythmia - Beta blockers
- Decrease blood pressure - vasodilators or calcium channel blockers
How can hydrophobic drugs or hormones act inside a cell? (5)
- Transported through the blood by a protein
- Released by the cell membrane that they act on
- Lipid soluble so can cross the membrane
- Binds to an intracellular receptor forming a hormone-receptor complex which transports it to the nucleus
- Signalling factor binds to DNA allowing transcription of a new protein
Define receptor selectivity
A drugs ability to target a selective population
Define affinity
The tendency of a drug to bind to a receptor
State 4 methods of inhaled drug delivery
- Dry powder inhaler
- Jet nebuliser
- Spacer device’s
- ultrasonic nebuliser
Define recepter specificity
A drugs ability to cause a particular action in a population
State 5 classes of drugs that can act on the respiratory system?
- Antihistamine
- Glucocorticoids/steroids
- Respiratory stimulants
- mucolytics
- cough suppressants
Give an example of a respiratory stimulant and the broad mechanism by which it works
doxapram stimulates peripheral chemoreceptors to activate the sympathetic nervous system
Give an example of a cough suppressant and the means by which it works
opioids inhibit the cough centre in the medulla
