Antihypertensives Flashcards
Desirable blood pressure?
115/75 or lower
Hypertensive urgency values
220/120
Secondary hypertension
We know what causes hypertension (5-10%) cocaine and oral contraceptives (increase BP) pheochromocytoma-tumor of adrenal gland
Primary hypertension
Cause is unknown
Malignant HT
220/120 or higher
Why hypertension kills
Stroke
MI
Left ventricular hypertrophy
Aneurysm
Renal failure
What controls our BP when we sit up suddenly
Neuronal-vascular control loop
What does Ca influx into vessels cause?
Contraction
What does K efflux into vessels cause?
Relaxation
Increase in cGMP in vessels causes?
Contraction
What does angiotensin II on vessels cause?
Contraction
What does DA influx into vessels cause?
Relaxation
What does endothelin receptor on vessels cause?
Contraction
When BP or Na levels in the kidney drop what happens
Renin is secreted
What controls our BP long term?
Kidney control loop (renin-angiotensin-aldosterone system)
What does renin do?
Angiotensinogen–>A1
What converts A1–>A2
Angiotensin converting enzyme (ACE)
What does ACE do?
A1–>A2
Bradykinin–>inactive product
What does bradykinin do?
Dilates arteries (drops BP)
Capillary leakage (edema) Activates sensory nerves-pain and itching
What does A2 do?
Vasoconstriction
Na retention
Aldosterone
One SE of all antihypertensives
Hypotension
Alpha-methyl DOPA
Central alpha-2 agonist
Prodrug: metabolized to alpha-methyl NE
SE:
Depression
Drowsiness
Dry mouth
Impaired Ejac.
Hepatic dysfunction
Clonidine
Central alpha-2 agonist
SE:
Depression
Drowsiness
Dry mouth
Impaired Ejac.
Unlabeled uses:
- Fibromyalgia-unspecified neuronal pain
- Insomnia
- Tourettes
- Opiate withdrawal
Propranolol
Tx of hypertension
Nonselective Beta blocker
Central and peripheral effects
Mech:
- Blocks B1 receptors on heart, prevents rise in HR
- Decreases renin secretion
- Renin converts Angiotensinogen→A1
SE:
- Into CNS→Depression
- Bradycardia→fatigue
- Impotence
- Lowers HDL, raises triglycerides
- Exacerbates asthma
Reserpine
Tx of HT
Central and peripheral effects/effector of post-ganglionic neuron
Causes depletion of post ganglionic neuron nt (NE)→ No vasoconstriction
SE: depression, drowsiness, diarrhea
alpha-methyl tyrosine
Tx of pheochromocytoma
Central and peripheral effects
Inhibits tyrosine kinase–preventing synthesis NE and epi
“Osin”s
Alpha 1 blockers
Blocks alpha 1 receptor on vascular smooth m
Tx of hypertension and some specifically treat BPH
Based on the drugs he gave us:
**If it ends in -azosin its for hypertension**
**If it ends in just -osin its used for BPH**
SE
- First dose effect-rapid drop in BP→orthostatic (postural) hypotension
- Do not confuse w/ first pass effect
More selective B blockers
Metoprolol
Acebutolol
Atenolol
Betaxolol
Nebivolol
SE:
- Fewer CNS effects
- Bradycardia
- Fatigue w/ exercise
Combined alpha and beta blockers
Block alpha1, beta1, and beta2
Labetalol
Carvedilol
SE:
- Postural hypotension
- Dry mouth
Angiotensin receptor blockers
“-Artan”s
SE:
- Decrease secretion of aldosterone
- Fetal abnormalities
- All agents that alter angiotensin system
- Pregnancy risk X
Endothelin blockers
“-entan”s
Tx of pulmonary arterial hypertension
SE:
- Fetal damage
- Testicular atrophy
- Hepatic toxicity
Minoxidil
Acts directly on smooth muscle
Prodrug
Opens K channels in arterial smooth m, increased efflux→hyperpolarization
Very refractory px
SE:
- Hypertrichosis-hair growth
- Rogaine
- Discontinuation→hair loss
- Edema and pericardial effusion→cardiac tamponade
- Fluid in sac around heart
Hydralazine
Act directly on smooth muscle
Arterial vasodilator
Increase in cGMP→relaxes smooth m
SE:
- Slow acetylators→lupus like syndrome
Diazoxide
Acts directly on smooth muscle
Opens K channels→hyperpolarization
SE:
- Decreased insulin secretion from beta cells in pancreas→hypoglycemia
Nitroprusside
Acts directly on smooth muscle
Drug of choice in hypertensive emergencies
Acts w/in seconds–given IV
Dilates art and veins→drop in BP
increases cGMP→relaxation
Rapidly degrades in soln into cyanide
Calcium channel blockers
“-ipine”s
Inhibit Ca influx into vascular smooth m
Prevent vasoconstriction
SE:
- Heartburn
- May worsen heart failure
ACE inhibitors
“-pril”s
ACE responsible for A1→A2
ACE responsible for bradykinin breakdown
Leads to decreased aldosterone secretion
SE:
- Rash
- Dry cough that cant be treated with suppressants
- Angioneurotic edema-swelling of nose, throat, resp tract
- Taste alteration
- Fetal damage
Aliskiren
Renin inhibitor
SE:
- Fetal damage
- Diarrhea
- Cough
- Angioedema
Fenoldopam
Activate D1 receptors
Given IV for HT emergencies
