Pharm angina drugs

B-blockers: target
B1 adrenergic receptors
B-blockers: pharm effects
reduced HR, contractility, BP (decrease cardiac work and myocardial O2 demand); decreased HR (longer coronary perfusion time, increases supply)
B-blockers: adverse effects
increased end diastolic ventricular volume (preload), increased ejection time (both increase myocardial work and O2 demand); bronchoconstriction, vasoconstriction, hypoglycemia
B-blockers: uses
angina pectoris, arrhythmias, HTN, MI
Sildenafil: target
phosphodiesterase 5
Sildenafil: mechanism
inhibition of PDE 5 increases cGMP concentration (decreases cGMP dephosphorylation to GMP), vasodilation of corpora cavernosa smooth muscle–>erection. Requires an intact parasympathetic function for the production of NO
Sildenafil: adverse effects
potentiates the action of organic nitrates–>hypotension and MI
Organic Nitrates: target
guanylyl cylcase via enzymatic generation of NO
Organic nitrates: PK
large 1st pass: give sub-lingual, patch or LARGE oral dose
Organic nitrates: pharm effects
cGMP enhances vascular smooth muscle relaxation–>venodilation reduces preload
Organic nitrates: uses
angina, CHF
Organic nitrates: adverse effects
postural hypotension, reflex sympathetic stimulation (palpitations), dilation of meningeal vessels (headache), interaction with sildenafil, tolerance (Monday disease)
Calcium Channel Blockers: tissues containing L-type Ca channels
cardiac and smooth muscle
Calcium Channel Blockers: pharm effects
decreased smooth muscle tone (BP), contractility, HR, SA and AV node conduction
Calcium Channel Blockers: uses
arrhythmias, angina, HTN
Calcium Channel Blockers: types
Nifedipine (vascular>cardiac), verapamil and diltiazem (vascular = cardiac)
Calcium Channel Blockers: target
L-type Ca channel
Calcium Channel Blockers: adverse effects
hypotension, refelx tachycardia (N), headache, myocardial depression (V/D), CHF, bradycardia, AV block, constipation
Beneficial combinations for angina
Nitrate + B-blocker (or verapamil), nifedipine + B-blocker (or verapamil)
Adverse drug combos for angina
nifedipine + nitrate (hypotension and MI); verapamil + b-blocker (depresses myocardium too much)