Cardiac downers Flashcards
(6 cards)
What equations pertain to BP?
MAP = CO x SVR
CO = CV x HR
Classify the antihypertensives?
Heart: BB, atenolol, metoprolol and esmolol are cardioselective.
Blood vessels:
Direct (NO): sodium nitroprusside and hydralazine, GTN and isosorbide
Indirect: CCB, alpha, K channel activators and mg
Kidneys diuretics and RAAS agentsCnS: centrally acting e.g. clonidine and methylodopa and and ganglion
What are different CC anatogonists and some common effects?
Special mentions?
Nimodipine and nifedipine
Decrease influx of Ca into cells
Both reduce SVR and BP
Common: good oral, significant first pass, PB over 95%
Nim = sub arach spasm and migraine, large increase in CBF = headache and vertigo
Nif: increased HR but decreased contractility, less cerebral. Angina, Reduced coronary spasm in PCI and Reynard
What are some special features of sodium nitroprusside?
Red brown powder, only IV
RBC and plasma protein hydrolysis
Broken down to cyanomethaemablobin so can cause cyanide poisoning (inhibits cytochrome system e.g. tachy, high RR, sweating, metabolic acidosis)
Arterial and veno and inhibits HPV
Tell me about clonidine?
Presynaptic A2 agonist used for BP, pain and sedation
100 oral BA
Urine, 50% unchanged
Increase release of endogenous opiates in cord
Discuss methyldopa?
Tablets and solution, variable oral, hepatic to @ methyl noradrenaline which is an @2 agonist. Taken up into CNS nerve terminals and decreases SNS tone when released.
CNS: sedation, vertigo and depression
Dark urine on standing
Constipation and deranged LFT’s
Haemolytic anaemia
