Flashcards in Pharmacology: Katzung Drugs used in Hypertension Deck (73)
What diuretics are used to treat hypertension?
What is the MOA and clinical applications for hyrochlorothiazide and chlorothalidone?
They block the Na/Cl transporter in the distal convoluted tubule and are used for
(2) mild edema
What is the MOA and clinical application for Furosemide?
Furosemide blocks the Na/K/2Cl transporter in the TALH. It is used for
(2) Heart failure
What adverse effects are associated with Hydrochlorothiazide and chlorothalidone?
(2) metabolic alkalosis
What are the adverse effects associated with Furosemide?
Why are diuretics used to treat hypertension?
Because diuretics will decrease blood volume and this will decrease the systemic blood pressure.
What are sympathoplegics?
Sympathoplegics are durgs that interfere with sympathetic control of cardiovascular function
Why are sypathoplegics used to treat hypertension?
Because they can decrease venous tone, HR, contractile force, cardiac output, and total peripheral resistance. Altogether this will decrease the blood pressure.
What centrally acting sympathoplegics are used to treat hypertension?
What is the MOA of clonidine?
clonidine is an alpha 2 agonist that decreases sympathetic outflow
What are the adverse effects associated with clonidine?
(2) Danger of rebound hypertension if drug is stopped.
(3) dry mouth
What is the MOA for methyldopa?
Methyldopa is a prodrug that is converted to methylnorepinephrine in the CNS with results like clonidine.
What are the adverse effects associated with methyldopa?
(2) hemolytic antibodies (positive coombs test)
What are the ganglion blocking drugs that can be used to treat hypertension?
(1) Hexamthonium (obsolete)
What is trimethaphan used for?
Trimethaphan is used as a short acting ganglion blocker in hypertensive emergencies. Creates controlled hypotension.
What is mecamylamine and what is it used for?
Mecamylamine is an oral ganglion blocker with a duration of several hours which is under investigation for use in smoking cessation.
What is the major compensatory response to ganglion blockers?
What toxicities are associated with ganglion blockers?
(1) blurred vision
(3) urinary hesitancy
(4) sexual dysfunction (sympathetic blockade)
(5) orthostatic hypotension (sympathetic blockade
Which post ganglionic neuron blockers are used to treat hypertension?
What are the clinical applications and MOA of reserpine?
reserpine blocks the loading of vesicles with catecholamines. It is used to treat
(2) Huntington's disease
What are the adverse effects associated with reserpine?
(2) severe psychiatric depression (at high doses)
What are the adverse effects and MOA of Guanethidine?
Guanethidine blocks re-uptake of norepinephrine. However, it causes severe orthostatic hypertension and is therefore no longer used.
Why are post ganglionic blockers used to treat hypertension?
Because they deplete stores of catcholamines thus inhibiting sympathetic activity. This decreases cardiac output and TPR.
What is the compensatory response to post ganglion blockers?
salt and water retention
Which alpha blockers are used to treat hypertension?
What is the mechanism of action for alpha blockers?
The alpha blockers
(1) reduce TPR
(2) reduce prostatic smooth muscle tone
What is prazosin used for?
(1) mild hypertension
(2) benign prostatic hyperplasia.
What adverse effects are associated with prazosin?
First dose orthostatic hypertension.
What differentiates doxazosin and terazosin from prazosin?
doxazosin and terazosin have a longer duration of action.