Alpha- 1 Selective antagonists and Alpha 2 Agonists

Question 1

alpha 1 selective antagonists is

Answer 1

adrenergic

Question 2

alpha 1 selective antagonists (-zosins… doxyzosin, tamulosin, terezosin)

indications

Answer 2

often used for BPH, mild HTN,

Question 3

alpha 1 selective antagonists (-zosins… doxyzosin, tamulosin, terezosin) pharmacodynamics

Answer 3

htn- they competitively inhibit postsynaptic alpha-1 receptors, which result in vasodilation of veins and arterials, and a decrease in total peripheral resistance and blood pressure.

BPH- they competitively inhibit postsynaptic alpha-1 receptors in prostatic stromal and bladder neck tissues. This reduces the sympathetic tone-induced urethral stricture causing BPH symptoms.

Question 4

alpha 1 selective antagonists (-zosins… doxyzosin, tamulosin, terezosin) caution and contraindications

Answer 4

heart failure, mi, angina, 
renal and hepatic impairment,
caution in elderly,
beers list,
 limited pediatric data,
avoid in pregancy and lactation

Question 5

alpha 1 selective antagonists (-zosins… doxyzosin, tamulosin, terezosin) ADT

Answer 5

fluid retention, nasal congestion, blurred vision, dry mouth, constipation, impotence, urinary frequency, headache, dizziness, fatigue, priapism (rare) , allergic reaction (rare).

first dose orthostatic hyptension that may lead to syncope

Question 6

alpha 1 selective antagonists (-zosins… doxyzosin, tamulosin, terezosin)
patient education

Answer 6

take at nighttime

Question 7

alpha 2 agonists

Answer 7

Clonidine (catapres)

Question 8

Clonidine (catapres) indications and pharmacodynamics

Answer 8

HTN , ADHD

HTN: stimulates alpha 2 receptors in the brain stem, activating inhibitory neuron, resulting in reduced sympathetic outflow from CNS, decrease peripheral resistance, heart rate, BP

ADHD- moa unclear, regulated activity in the prefrontal cortex, responsible for emotions, attention and behaviors.

Question 9

Clonidine (catapres) patient education

Answer 9

do not stop abruptly.

due to down regulation of alpha 2 receptors.

Question 10

Clonidine (catapres) caution and contraindications

Answer 10

severe coronary insufficiency,
recent MI,
renal impairment,
cerebral vascular disease,
elderly(beers list),
approved in pediatrics,
caution in pregnancy, avoid in lactation.

Question 11

Clonidine (catapres) ADRs

Answer 11

drowsiness, bradycardia, constipation, impotence, nightmares

Question 12

methyldopa indications and pharmacodynamics

Answer 12

HTN

stimulation of the central alpha 2 receptors by methyldopa’s metabolite alpha methylnorepinephrine. produces a decrease in sympathetic outflow to the heart, kidneys and blood vessels.

Question 13

methyldopa ADRS

Answer 13

edema, sedation, bradycardia, hypotension, skin rash, myalgias, elevated LFT
Rare: hemolytic anemia, hepatotoxicity.

Question 14

methyldopa contraindications and cautions

Answer 14

severe coronary insufficienct,
histroy of bradycardia,
caution in renal impairment,
avoid in active liver disease ie cirrhosis or liver disease,
caution in cerebrovascular disease,
compatible for pregnancy, not 2st line.
avoid with bradycardia
avoid in lactation,
not recommended in pediatrics,
caution in elderly (beers list)