Vasoactive and antiplatelet agents

shevyatiwari's version from 2015-04-25 00:30

Calcium Channel Blockers

Question Answer
Good oral absorptionT
Poorly protein boundF, largely protein bound
All are excreted predominantly by the kidneysF. Diltiazem is excreted via the faeces after extensive deacetylation
Amlodipine has the shortest half life and shortest peak plasma levelsF. Longest for both
Verapamil is a first choice Ca channel blocker in dermatologyF. Strong depressor of AV conduction
Nifedipine increases RBC deformity as well as show platelet anti aggregation activityT
Diltiazem is the drug of choice for Raynaud'sF, Nifedipine is superior to diltiazem
Diltiazem is the drug of choice for calcinosis cutisT
Nifedipine and amlodipine are drugs of choice for enhancing wound healingT
Verapamil may be used IL for keloidsT
Diltiazem and nifedipine can be used orally only for chronic anal fissuresF, can also use topical
First line drugs for cyclosporin induced HTNT, esp Isradipine and Nifedipine
Diltiazem has more severe adverse effects than nifedipineF. Diltiazem and amlodipine have less severe S/E than nifedipine
CaChBlockers can cause eczema in the elderlyT
Cat BF, C

B blockers

Question Answer
Propranolol, carvediolol and metoprolol are hydrophilic B blockersF. Lipophilic. Well absorbed, short half lives, distribute widely and cross BBB, cf, atenolol and sotalol which are hydrophilic
Labetalol and carvedilol are less likely to reduce BP than atenololF
Sotalol is the b blocker of choice in dermatologyF. Class III antiarrhythmic properties, increases risk of cardiac arrhyhmia
B2 blockade may be useful in treating woundsT
Selective B blockers are useful in the treatment of rosaceaF. Non selective such as propranolol, nadolol, carvedilol
Carvedilol is the best B blocker or flushingT
B blockers can cause lichenoid, eczematous and psorasiform eruptionsT
Cat BF. Sotalol, acebutolol and pindolol are B, others are C except for atenolol D


Question Answer
AKA monoacetylsalicylic acidF. Acetylsalicylic acid
Poorly absorbedF. Rapidly absorbed from stomach and small intestine
Peak plasma at 2 hoursT
Bound to albuminT, 80%
Bound drug is activeF. Free drug
ProteolysedF. metabolised by liver
Rate of metabolism depends on rate of urinary excretion which depends on urinary pHT
Acidic urine -> faster excretionF, alkaline urine -> faster excretion
Inhibits TXA2 and PGI2T. Higher doses are needed for inhibition of PGI2 cf TXA2
Hypersensitivity, PUD, GI bleeding are complicationsT
Shouldn't be taken with food/waterF
Cat DT
Higher doses cause reversal of the anti platelet effectT


Question Answer
Peak levels in 1.5 hoursT
Bound to PPT
ProteolysedF, metabolised in the liver
Excreted in the urineF. Bile
Interacts with TXA2 and PGI2 like aspirinT
VasoconstrictorF, dilator
Can be used post MIF, C/I
Combination with aspirin increases bleeding riskF, same risk
Hypotension, dizziness, headache, tachycardia, worsening of CAD are S/ET
Cat BT
No FDA approved dermatology indicationsT
Prolongs the survival of plateletsT


Question Answer
Methyl xanthine derivative, specific PDE inhibitorF, non specific
Poor oral absorptionF, well absorbed
No first pass hepatic metabolismF, significant first pass hepatic metbolism
Excreted in the kidneysT
Short half life of 4-6 hoursT
Increases erythrocyte and leucocyte deformabilityT
Enhances neutrophil adhesion and activationF, inhibits
Enhances platelet aggregation and activationF, reduces
Inhibits TNFaT
Intolerance of methyl xanthine is a C/IT
Nausea, GI disturbance dizziness, and headache are S/ET
Cat BF, C


Question Answer
Topical formulations have been used in Raynaud's and tineaT

PDE5 inhibitors

Question Answer
PDE5 inhibition -> increased cAMPF, cGMP
Sildenafil is metabolised by CYP2D6F, 3A4 > 2C9
Can be used with NO as an adjunctF, C/I
MI is a S/EF, C/I along with unstable angina, hypotension, hypertension, arrhythmias or other vascular conditions
Headache, flushing, dyspepsia and nasal congestion are S/ET


Question Answer
PGI1 analogueF, PGI2
Reduces connective tissue GFT
Used in Raynaud's and systemic sclerosisT


Question Answer
Chimeric mabF, human
Recognises VGEF receptors 1 and 2T
Anti angiogenic and antitumour activityT
Acts on perilesional keratinocytes in psoriasisF, lesional