Annette Battersby Flashcards
Which type of drug is diamorphine?
Opioid agonist - heroin
Is diamorphine lipid soluble?
Yes
What are the central actions of diamoprhine?
- Reduce sympathetic vascular reflexes (vasocontriction)
- Veno and arteriolar dilation
- Euphoria and sedation
- Release histamine (vasodilator)
Preload and afterload reduced and therefore relieve heart failure
Unwanted side effects of diamorphine?
- Resp depression and sedation
- Hypotension
- Bronchospasm
- Nausea and vomiting
What are the therapeutic effects of loop diuretics in HF?
- Promotes Na+ & H20 excretion (reduces pre-load)
- May promote direct vasodilatation (reduce afterload)
- Increase excretion of K+, Mg2+, Ca2+; reduced urate
excretion
Desired Therapeutic Effects:
- Relief of heart failure symptoms (reduce pre-load)
- Treatment of Na+ and H2O overload
Unwanted side effects of loop diuretics?
- Hypovolaemia & hypotension
- Hypokalaemia; (Hypo –magnesaemia & -calcaemia)
- Hyperuricaemia
- Dose-related hearing loss (rarely) because same channels are in the inner ear
What are the functions of nitrates in HF?
Examples: Glyceryl trinitrate, Isosorbide mononitrate
Indirect nitric oxide (NO) donors
Activate Guanylate cyclase in vascular smooth
muscle cells → cGMP
Predominantly venoselective
Also inhibit platelet aggregation & endothelial
inflammation
Effect: Veno- and (vaso-) dilatation
Reduce preload and to a lesser extent afterload
What is the use of beta blockers in HF?
SA node: Decreases heart rate
Myocardium: Decreases contractility
Renal: Decreases renin release, RAAS activation,
vasoconstriction, fluid retention → Decrease blood
pressure
Saves energy and oxygen demand
Reduces Ca cycling and propensity for arrhythmias
Halts progression of the disease
Side effects of spironolactone?
- Hypotension
- Renal impairement
- K+ excess
MOA of digoxin?
Digoxin is negatively chronotropic (it reduces the heart rate) and
positively inotropic (it increases the force of contraction). In atrial
fibrillation and flutter its therapeutic effect arises mainly via an indirect
pathway involving increased vagal (parasympathetic) tone. This reduces
conduction at the atrioventricular (AV) node, preventing some impulses
from being transmitted to the ventricles, thereby reducing the ventricular
rate. In heart failure, it has a direct effect on myocytes through
inhibition of Na+/K+-ATPase pumps, causing Na+ to accumulate in
the cell. As cellular extrusion of Ca2+ requires low intracellular Na+
concentrations, elevation of intracellular Na+ causes Ca2+ to accumulate
in the cell, increasing contractile force.
Indications for digoxin
- In atrial fibrillation (AF) and atrial flutter, digoxin is used to reduce
the ventricular rate. However, a β-blocker or non-dihydropyridine calcium
channel blocker is usually more effective. - In severe heart failure, digoxin is used as a third-line treatment in
patients who are already taking an ACE inhibitor, β-blocker and either an
aldosterone antagonist or angiotensin receptor blocker. It is used at an earlier stage in patients with co-existing AF.
Compare the indications, mechanism of action and place in therapy of heparin and warfarin and novel oral anticoagulants.
See notes in drug book
Is aspirin effective in the prevention of stroke in a fib?
No- aspirin is not indicated for stroke prevention in A Fib
What is the care pathway in VTE?
Patient admitted to hospital»_space; assess risk of VTE»_space;> assess bleeding risk»_space;> balance risk of VTE and bleeding»_space;> offer VTE prophylaxis if approp. do not offer pharm VTE prophylaxis if pt. has any risk factor for bleeding and risk of bleeding outweighs the risk of VTE»_space;» Reassess risk of VTE and bleeding within 24 hours of admission and whenever clinical situation changes
What are the main differences between UFH and LMWH?
UFH: short half life and accelerates inhibition of Xa and thrombin
LMWH: longer half life and accelerates inhibition of Xa more than thrombin
