Week 8 Flashcards
What type of drug at atenolol?
Beta 1 receptor antagonist (beta blocker)
What are beta 1 blockers used for?
- Angina
- post MI
- coronary artery disease
What are the contraindications of beta blockers
Remember DAC!!
- diabetes
- asthma
- COPD
- heart block
Why are beta blockers contraindicated asthmatics/people with CoPD?
Beta antagonists would cause bronchospasms which is a problem for asthmatics. There beta blockers are dangerous for this group of people
Mrs. tibble had been on beta blockers for 4 weeks to help with her palpitations. Why did the doctor suggest her easing off the medication gradually rather than stopping immediately?
B adrenorecptors have proliferated during the course of Mrs Tibble taking her medication. As Mrs Tibble would have more adrenoreceptors that pre-medication, if she stopped suddenly TACHCARDIA and HYPERTENSION would arise
What type of drug is verapimil?
They are a class 4 drug; calcium voltage gated channel blocker
What is the mechanism of action of verapimil?
Lipid soluble enters cell, Ca2+ channels at pacemaker cells are blocked, impulse conduction decreases, vasodilation
What are the adverse reactions of verapimil!?
Odema, Constipation, dizziness
Why does peripheral oedema occur with taking verapimil or calcium channel blocker drugs?
1) Decrease in arterial resistance
2) not matched by venous return
3) increased hydrostatic pressure so you get fluid shift to interstitial compartment
What conditions are managed by calcium channel blockers?
- High blood pressure (less contraction, less blood, less resistance)
- Angina (decrease in arterial pressure)
What is the mechanism of action of adrenaline?
Increases heart rate and increases contractility of heart
Where will adrenaline have more of an effect within the heart?
SAN as more B 1 adrenoreceptors are found here
What are the adverse drug reactions associated with adrenaline?
Too much causes chest pain as more constriction, palpitations and hypertension
What are the four classes of drugs according to vaughan williams
Classes ….
1) sodium voltage gated channel blockers
2) Beta adrenoreceptor blockers
3) K+ v gated channel blockers
4) Ca2+ gated channel blockers
