NR565 midterm QUESTIONS AND VERIFIED SOLUTIONS 3
Alpha 2 Agonist - ✔✔Clonidine Methydopa Guanabenz Guanfacine Alpha 2 Agonist
Pharmacodynamics - ✔✔inhibit cardiac acceleration and vasoconstriction centers in the
brain-> decrease in peripheral resistance, renal vascular resistance, HR, and BP May lead
to Na+ retention (increase blood volume-> increase BP) give with a diuretic if this occurs
Clonidine adverse reactions - ✔✔DRY MOUTH, REBOUND HTN, GYNECOMASTIA,
bradycardia, AV block, palpitations, tachycardia, hallucinations, sleep disorders, contact
dermatitis, OH, constipation, nausea, urinary retention, decreased sexual activity, wt gain,
leg cramps, thrombocytopenia Guanabenz and Guanfacine adverse reactions - ✔✔OH
with standing, somnolence, fatigue, nausea, lethargy, hypotension, insomnia, dizziness,
abdominal pain Methydopa adverse reactions - ✔✔Hemolytic anemia, positive coombs
after 6 months of therapy Clonidine Metabolism & Excretion - ✔✔Easily absorbed in GI
tract and skin Lipid-Soluble- enter Brain (CNS) from circulation rapidly Crosses the
placenta and found in breast milk 50% hepatically metabolized 50% excreted in urine
Guanabenz & Guanfacine Metabolism and Excretion - ✔✔Metabolized by CYP3A4 in liver
and excreted by the kidneys- 50% eliminated in urine Guanabenz- <1% unchanged in urine
Methydopa Metabolism and Excretion - ✔✔Not completely absorbed in the gut Absorbed
via aromatic amino acid transport system Crosses placenta and found in breast milk 20%
of drug in plasma 70% excreted in urine Clonidine Contraindications and Precautions -
✔✔Caution with cerebrovascular disease, depression, Hx of bradycardia Pregnancy
Category Class C Methydopa Contraindications and Precautions - ✔✔Caution with
cerebrovascular disease Pregnancy Category B- pass to breast milk REBOUND HTN if
given with Beta-Blocker Coombs Hemolytic anemia Guanabenz & Guanfacine
Contraindications and Precautions - ✔✔Guanabenz- Pregnancy Category C may cause
gynecomastia Guanfacine- Pregnancy Category B Clonidine Drug Interactions - ✔✔Beta-
Blockers -> Rebound HTN * may be prescribed together for MI prophylaxis - taper Beta-
Blocker first TCA- decrease antihypertensive effects- may need a higher dose Methydopa
Drug Interactions - ✔✔TCA- Decrease the antihypertensive effects Beta-Blockers-
Rebound HTN Clonidine Clinical Use and Dosing - ✔✔Methyldopa and Clonidine with a
diuretic (2nd line) Increase dose at weekly intervals Divide doses BID to decrease sedation
smaller doses for renal impaired- give guanfacine used to treat ETOH, heroin, nicotine
withdrawl ADHD available in pediatric doses caution with elderly due to Na+ retention and
OH Methyldopa Clinical Use and Dosing - ✔✔Methyldopa- Ist line when pregnant
Methyldopa and Clonidine with a diuretic (2nd line) to treat HTN Increase dose at weekly
intervals Divide doses BID to decrease sedation smaller doses for renal impaired- give
, guanfacine pediatric dose available caution with elderly due to Na+ retention and OH
Alpha 2 Agonist Monitoring - ✔✔Monitor BP, WT, fluid status renal status- cret prior to tx
and at regular intervals liver function- prior to tx and 6-12 months Selective Alpha 1
Antagonist - ✔✔Doxazosin Prazosin Terazosin Tamsulosin Alfuzosin Silodosin Selective
Alpha 1 Antagonist Pharmacodynamics - ✔✔Block catecholamine in vascular smooth
muscle, bladder, and prostate block postsynaptic alpha 1 receptors in vasculature ->
decrease in arterial and venous vasoconstriction-> decrease peripheral resistance and BP
(diastolic Doxazosin Metabolism and Excretion - ✔✔1st pass metabolism in liver excreted
in feces Prazosin Metabolism and Excretion - ✔✔Demethylation and conjugation in the
liver and excreted in the feces Terazosin Metabolism and Excretion - ✔✔minimal hepatic
1st pass metabolized by CYP450 enzymes eliminated in urine Alfuzosin Metabolism and
Excretion - ✔✔metabolized to inactive metabolites via CYP3A4 eliminated in feces
Silodosin Metabolism and Excretion - ✔✔Metabolized by hepatic CYP3A4 and
glucuronidation and alcohol Active Metabolite 1/2 life of 24 hours Selective Alpha 1
Antagonist Contraindications and Precautions - ✔✔"azosin" contraindicated in volume
depletion due to peripheral vasodilation causing decreased venous return to the heart
leading to HF Alfuzosin Contraindications and Precautions - ✔✔Don't give to patients with
mild to moderate hepatic impairment Silodosin Contraindications and Precautions -
✔✔Don't give to patients with SEVERE hepatic impairment CrCL 30-49- 1/2 the dose CrCL
<30- don't give CrCL- >50 no change to dose needed Doxazosin, Prazosin, and Terazosin
Contraindications and Precautions - ✔✔Pregnancy Category C Teratogenicity and reduced
fertility excessive found in breast milk Metabolized in liver- start dosing slow enterohepatic
recycling ?- Doxazosin Selective Alpha 1 Antagonist Adverse Drug Reactions - ✔✔1st dose
orthostatic hypotension- syncope 30-90 min after initial dose- start with 1mg dose and
slowly increase the dose in 2 wk interval Terazosin (most common) Prazosin (moderate)
Doxazosin (least common) Fluid Retention- give with diuretic nasal congestion, blurred
vision, dry mouth, constipation, impotence, urinary frequency, dizziness, HA, fatigue,
tachycardia, nausea Selective Alpha 1 Antagonist Drug Interactions - ✔✔ETOH,
antihypertensives, nitrates- Postural Hypotension Doxazosin- fewest interactions
Prazosin- most interactions Cimetidine with Tamsulosin- decreases tamsulosin effects
Selective Alpha 1 Antagonists HTN - ✔✔Doxazosin drug of choice to treat HTN and BPH in
men because it may lower LDL, Increase insulin and regress Left ventricular HF Long
acting: 1 daily dose- monitor BP 2-6 hours after dose pills are scored by 1/2 dosing
Parazosin- 2-3x day- monitor BP 2-3 hours after dose. No tachycardia seen terazosin- 1-2 x
day- monitor BP 2-3 hours after dose may treat BPH too If diuretic added decreased dose
for 2-3 days and then retitrate Selective Alpha 1 Antagonist BPH - ✔✔Tamsulosin 0.4mg
Alpha 2 Agonist - ✔✔Clonidine Methydopa Guanabenz Guanfacine Alpha 2 Agonist
Pharmacodynamics - ✔✔inhibit cardiac acceleration and vasoconstriction centers in the
brain-> decrease in peripheral resistance, renal vascular resistance, HR, and BP May lead
to Na+ retention (increase blood volume-> increase BP) give with a diuretic if this occurs
Clonidine adverse reactions - ✔✔DRY MOUTH, REBOUND HTN, GYNECOMASTIA,
bradycardia, AV block, palpitations, tachycardia, hallucinations, sleep disorders, contact
dermatitis, OH, constipation, nausea, urinary retention, decreased sexual activity, wt gain,
leg cramps, thrombocytopenia Guanabenz and Guanfacine adverse reactions - ✔✔OH
with standing, somnolence, fatigue, nausea, lethargy, hypotension, insomnia, dizziness,
abdominal pain Methydopa adverse reactions - ✔✔Hemolytic anemia, positive coombs
after 6 months of therapy Clonidine Metabolism & Excretion - ✔✔Easily absorbed in GI
tract and skin Lipid-Soluble- enter Brain (CNS) from circulation rapidly Crosses the
placenta and found in breast milk 50% hepatically metabolized 50% excreted in urine
Guanabenz & Guanfacine Metabolism and Excretion - ✔✔Metabolized by CYP3A4 in liver
and excreted by the kidneys- 50% eliminated in urine Guanabenz- <1% unchanged in urine
Methydopa Metabolism and Excretion - ✔✔Not completely absorbed in the gut Absorbed
via aromatic amino acid transport system Crosses placenta and found in breast milk 20%
of drug in plasma 70% excreted in urine Clonidine Contraindications and Precautions -
✔✔Caution with cerebrovascular disease, depression, Hx of bradycardia Pregnancy
Category Class C Methydopa Contraindications and Precautions - ✔✔Caution with
cerebrovascular disease Pregnancy Category B- pass to breast milk REBOUND HTN if
given with Beta-Blocker Coombs Hemolytic anemia Guanabenz & Guanfacine
Contraindications and Precautions - ✔✔Guanabenz- Pregnancy Category C may cause
gynecomastia Guanfacine- Pregnancy Category B Clonidine Drug Interactions - ✔✔Beta-
Blockers -> Rebound HTN * may be prescribed together for MI prophylaxis - taper Beta-
Blocker first TCA- decrease antihypertensive effects- may need a higher dose Methydopa
Drug Interactions - ✔✔TCA- Decrease the antihypertensive effects Beta-Blockers-
Rebound HTN Clonidine Clinical Use and Dosing - ✔✔Methyldopa and Clonidine with a
diuretic (2nd line) Increase dose at weekly intervals Divide doses BID to decrease sedation
smaller doses for renal impaired- give guanfacine used to treat ETOH, heroin, nicotine
withdrawl ADHD available in pediatric doses caution with elderly due to Na+ retention and
OH Methyldopa Clinical Use and Dosing - ✔✔Methyldopa- Ist line when pregnant
Methyldopa and Clonidine with a diuretic (2nd line) to treat HTN Increase dose at weekly
intervals Divide doses BID to decrease sedation smaller doses for renal impaired- give
, guanfacine pediatric dose available caution with elderly due to Na+ retention and OH
Alpha 2 Agonist Monitoring - ✔✔Monitor BP, WT, fluid status renal status- cret prior to tx
and at regular intervals liver function- prior to tx and 6-12 months Selective Alpha 1
Antagonist - ✔✔Doxazosin Prazosin Terazosin Tamsulosin Alfuzosin Silodosin Selective
Alpha 1 Antagonist Pharmacodynamics - ✔✔Block catecholamine in vascular smooth
muscle, bladder, and prostate block postsynaptic alpha 1 receptors in vasculature ->
decrease in arterial and venous vasoconstriction-> decrease peripheral resistance and BP
(diastolic Doxazosin Metabolism and Excretion - ✔✔1st pass metabolism in liver excreted
in feces Prazosin Metabolism and Excretion - ✔✔Demethylation and conjugation in the
liver and excreted in the feces Terazosin Metabolism and Excretion - ✔✔minimal hepatic
1st pass metabolized by CYP450 enzymes eliminated in urine Alfuzosin Metabolism and
Excretion - ✔✔metabolized to inactive metabolites via CYP3A4 eliminated in feces
Silodosin Metabolism and Excretion - ✔✔Metabolized by hepatic CYP3A4 and
glucuronidation and alcohol Active Metabolite 1/2 life of 24 hours Selective Alpha 1
Antagonist Contraindications and Precautions - ✔✔"azosin" contraindicated in volume
depletion due to peripheral vasodilation causing decreased venous return to the heart
leading to HF Alfuzosin Contraindications and Precautions - ✔✔Don't give to patients with
mild to moderate hepatic impairment Silodosin Contraindications and Precautions -
✔✔Don't give to patients with SEVERE hepatic impairment CrCL 30-49- 1/2 the dose CrCL
<30- don't give CrCL- >50 no change to dose needed Doxazosin, Prazosin, and Terazosin
Contraindications and Precautions - ✔✔Pregnancy Category C Teratogenicity and reduced
fertility excessive found in breast milk Metabolized in liver- start dosing slow enterohepatic
recycling ?- Doxazosin Selective Alpha 1 Antagonist Adverse Drug Reactions - ✔✔1st dose
orthostatic hypotension- syncope 30-90 min after initial dose- start with 1mg dose and
slowly increase the dose in 2 wk interval Terazosin (most common) Prazosin (moderate)
Doxazosin (least common) Fluid Retention- give with diuretic nasal congestion, blurred
vision, dry mouth, constipation, impotence, urinary frequency, dizziness, HA, fatigue,
tachycardia, nausea Selective Alpha 1 Antagonist Drug Interactions - ✔✔ETOH,
antihypertensives, nitrates- Postural Hypotension Doxazosin- fewest interactions
Prazosin- most interactions Cimetidine with Tamsulosin- decreases tamsulosin effects
Selective Alpha 1 Antagonists HTN - ✔✔Doxazosin drug of choice to treat HTN and BPH in
men because it may lower LDL, Increase insulin and regress Left ventricular HF Long
acting: 1 daily dose- monitor BP 2-6 hours after dose pills are scored by 1/2 dosing
Parazosin- 2-3x day- monitor BP 2-3 hours after dose. No tachycardia seen terazosin- 1-2 x
day- monitor BP 2-3 hours after dose may treat BPH too If diuretic added decreased dose
for 2-3 days and then retitrate Selective Alpha 1 Antagonist BPH - ✔✔Tamsulosin 0.4mg
