What drug based on MoA? _Dilates Arterioles_ no vein effect Metabolite: _opens K+ channels in smooth muscle_ of arterioles Topical

_MINOXIDIL_ Vasodilator Used for HAIR GROWTH = Rogaine may provoke _ANGINA_ Headache / Sweating / Hirsutism

_CARDIAC DEPRESSION_ Greater in Non-DHP's (Verapamil/Diltiazem) \> DHP's (amlodipine) BradyCardia / AV block / HF Short Acting Nifedipine = ↑risk of MI --\> use LONG ACTING Dizziness / Constipation / Peripheral Edema FLushing / Nausea

similar to ACE-inhibitors EXCEPT FOR: _COUGH_ & _ANGIOEDEMA_

What drug based on MOA? Direct agonist of a-adrenoreceptors @medulla: ↓sympathetic outflow / ↓BP / ↓ Bradycardia ↑ParaSympathetic Tone Initially, ↑BP - \> due to stimulation of peripheral a-receptors on arterioles when given IV = transient vasoconstriction

_CLONIDINE_ Guanzbenz & Guanfacine CNS-Acting Sympathoplegics

8 - Pharmacology of AntiHT's Flashcards by Karlo Sison

What drug based on MOA?

Selectively block a1-adrenoreceptors
@arterioles & venules

↓Arterial pressure
by dilation of resistance/capacitance BVs

Vasodilation –> HypoTensive effect

*a1-adrenoceptor Antagonists**
*Prazosin / Terazosin / Doxazosin**

orthostatic hypotension

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What drug based on MOA?

**Inhibit NaCl Reabsorption in the DCT**
in luminal (urine-side) epithelium

Direct effect:
Block Na+/Cl- Transporter

Enhances Ca2+ Reabsorption

THIAZIDES
Chlorthiazide / HCTZ / Methylclothiazide

Non-thiazide Sulfonamide:
Chlorthalidone / Indapamide / Metolazone

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Fenoldopam

Class / MoA / ADR

Parenteral Vasodilator

*Dilates Arterioles**
not veins*

D1 Agonist –> also produces natriuresis

↑Intraocular pressure = do NOT use in GLAUCOMA pts

ADRs:
TachyCardia & Provokes ANGINA

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What drug based on MoA?

*Dilates Arterioles**
no vein effect*

TachyPhalaxis
develops rapidly, limits use in MONOtherapy

Usually used for:
Combination Therapy for Severe HTN

HYDRALAZINE
Oral Vasodilator

may provoke ANGINA

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Which Beta Blockers have

Intrinsic Sympathomimetic Activity = ISA

Partial AGONIST @ B2-Ne Receptors
but is overidden by:
B1-NE blockade

ISA BB’s = PAP

Pindolol / Acebutolol / Penbutolol

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What drug based on MoA?

*Dilates Arterioles**
no vein effect*

Metabolite: opens K+ channels in smooth muscle
of arterioles

Topical

*MINOXIDIL**
*Vasodilator**

Used for HAIR GROWTH = Rogaine

may provoke ANGINA*
*Headache / Sweating / Hirsutism**

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What drug based on MoA?

*Blocks AT2 Effects**
antagonism of* AT2 type 1 receptor

*ARBS**
artans

NO COUGH, NO EFFECT ON BRADYKININ

clinically similar effects to ACE-i’s

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*ADR’s of BETA BLOCKERS**
olols

BradyCardia / ↓cardiac contractility & excitibility

CNS = sedation / depression / sleep disturbance

REBOUND SYMPATHETIC STIMULATION
upon abrupt withdrawal = nervousness / tachycardia / HTN

HYPOGLYCEMIA
may exacerbate hypoglycemic episodes in insulin dependent diabetics
BetaBlockers may MASK hypoglycemia in diabetic pts

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CCB ADR’s

*CARDIAC DEPRESSION**
*Greater in Non-DHP’s (Verapamil/Diltiazem)** > DHP’s (amlodipine)
*BradyCardia / AV block / HF**

Short Acting Nifedipine = ↑risk of MI –> use LONG ACTING

Dizziness / Constipation / Peripheral Edema

FLushing / Nausea

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Diazoxide

Class / MoA / ADR

Parenteral Vasodilator

*Dilates Arterioles**
not veins*

Opens K+ channels = stabilize smooth muscle membranes of arterioles

ADRs:
TachyCardia & Provokes ANGINA

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Which Beta Blockers have

a-NE-blocking Activity

Stereoisomers have BOTH:
B-NE & a-NE antagonist activity

LABETOLOL

CARVEDILOL

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What drug based on MOA?

Inhibits synthesis of AT2
↓vasoconstrictor activity
↓aldosterone release –> Na+ & H2O Retension

Blocks breakdown of BRADYKININ
↑bradykinin = vasoDilation

↓PVR

ACE INHIBITORS

↓BP by ↓PVR

CO & HR are UNCHANGED

no reflex tachycardia

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ADRs of ARBS

*similar to ACE-inhibitors**
EXCEPT FOR:*
*COUGH_ & _ANGIOEDEMA**

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What drug based on MOA?

Direct agonist of a-adrenoreceptors @medulla:
↓sympathetic outflow / ↓BP / ↓Bradycardia
↑ParaSympathetic Tone

Initially, ↑BP

> due to stimulation of peripheral a-receptors on arterioles
when given IV = transient vasoconstriction*

*CLONIDINE**
*Guanzbenz** & Guanfacine

CNS-Acting Sympathoplegics

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Special Uses for
BETA BLOCKERS w/ ISA

ISA BB’s = PAP

Pindolol / Acebutolol / Penbutolol

↓PVR –> ↓BP

LESS depression of CO & HR
due to greater B2 agonist > B2 antagonist activity

Useful in pts with:
Bradyarrhythmias & Peripheral Vascular Disease

do NOT use in patients with ANGINA

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What drug based on MOA?

In brain:
a-methyl-NE –> stimulates post-synaptic a-adrenoreceptors
↓PVR ~↓CO

↓Sympathetic Outflow

in periphery:*
*a-methyl-NE replaces NE stores** as false transmitter
not responsible for antiHTN action*

METHYLDOPA
CNS-acting Sympathoplegics

What drug based on MOA?

Taken up into pre-synaptic NE vesicles –> REPLACES NE

_*Inhibits release of* NE_
@ postganglionic sympathetic effector site on BV

= VASODILATION

*Guanethidine**
*Adrenergic Neuron Blocker**

more potent vs Reserpine

*SEVERE HTN**
many drug interations*

Impairs baroreceptor reflex –> orthostatic hypotension

ADR’s

THIAZIDES
Chlorthiazide / HCTZ / Methylclothiazide

Non-thiazide Sulfonamide:
Chlorthalidone / Indapamide / Metolazone

HypoKALEMIA

HyperUricemia
gout

HyperGlycemia & HyperLipidemia
<15% increase in serum cholesterol & LDL

ADR’s

CNS-Acting Sympathoplegics
Methyldopa / Clonidine

Guanfacine / Guanabenz

Dry Mouth + Sedation

SUDDEN WITHDRAWAL –> SEVERE HTN CRISIS
if after chronic use
Due to: Rebound sympathetic activity
dose should be TAPERED OFF

Compelling Indications for

ACE INHIBITORS

HF** / **Recent Strole
use with DIURETICS

Post - MI

Diabetes

CKD

What drug based on MOA?

INHIBITION of CA++ Influx
into smooth muscle of arterioles

↓PVR

More Cardiac Depressant activity vs counterpart

↓Conduction thru AV Node

↓HR –> ↓Cardiac Output

Negative Inotropic Effect

*Non-DHP Calcium Channel Blockers**
*Verapamil > Diltiazem**

Vasodilator

More cardiac deppressant vs DHP’s

Sodium Nitroprusside

Class / MoA / ADR

Parenteral Vasodilator

Dilates Arterioles & VEINS

Potent –> used for HYPERTENSIVE EMERGENCIES

ADRs:
Accumulation of CYANIDE

TachyCardia & Provokes ANGINA

What drug based on MOA?

Blocks uptake of: NE / DA / 5-HT into pre-synaptic vasicles

depletion of NE stores –> inhibit release of NE
@ post ganglionic sympathetic effector site on BVs

= VASODILATION

*RESERPINE**
*Adrenergic Neuron Blocker**

Mild-Moderate HTN

may cause PARKINSONISM = DA depletion

Impairs baroreceptor reflex –> orthostatic hypotension

Ace Inhibitor ADRs

Acute RENAL failure

HYPERkalemia
more likely w/ renal insufficiency / diabetes
due to inhibitory action on aldosterone secretion

AngioEdema

DRY COUGH

*ASPIRIN + NSAIDS**
may diminish HypoTensive response*
*PREGNANCY WARNING**
contraindicated during 2nd & 3rd trimesters*

**What drug based on MOA?** _**Primarily: ↓****CO**_ Kidneys: **antagonize renin production** Peripheral sympathetic neurons on BVs: **antagonize pre-synaptic B-adrenoceptors** = **vasodilation** *unlikely brain effects:*

* *_BETA BLOCKERS_** * *-OLOLS** Non Selective = NPC Propranolol / Naldolol / Carteolol Selective B1 = BBEAM Bisoprolol / Betaxolol / Esmolol (IV) / **Atenolol** / **Metoprolol**

What drug based on MOA? **Inhibition of Na+ influx through ion channels** **@late DCT & collecting tubule** (luminal = urine-side)

**_K+-Sparing Diuretic_** inhibit Na+ influx in distal & collecting tubules **Triamterene + Amiloride** *avoids K+ depletion, of Thiazides* ENHANCES natriuretic effect of other diuretics

**CNS-Acting Sympathoplegics USES** Methyldopa / Clonidine Guanfacine / Guanabenz

↓**Sympathetic nervous system OUTFLOW** from brain **Moderate HTN** **_Intact barorecetor reflex_** advantage = ***_low orthostatic HTN_***

**What drug based on MOA?** **_INHIBITION of CA++ Influx_** into smooth muscle of arterioles ↓**PVR** **Reflex sympathetic Activation** --\> **TachyCardia** ↑**HR** --\> **↑CO**

* *_DHP Calcium Channel Blockers_** * *Amlodipine / Nifedipine / Felodipine** **Vasodilator** ***less cardiac depression*** vs NON-DHP's

What drug based on MOA? **Block Aldosterone receptors** @ **late DCT**

* *_K+-Sparing Diuretic_** * *ALDOSTERONE ANTAGONIST** **Spironolactone + Eplernone** *avoids K+ depletion, of Thiazides* ENHANCES natriuretic effect of other diuretics

**Thiazide Uses** Chlorthiazide / HCTZ / Methylclothiazide Non-thiazide Sulfonamide: Chlorthalidone / Indapamide / Metolazone

Most Frequently prescribed diuretic class **_Mild-Moderate Essential HTN_** w/ normal cardiac & renal fxn ***Lower Doses*** = **similar antiHT action vs higher doses** **Higher doses = MORE NATRIURETIC effect**

**Which drug have a COMPELLING INDICATION for:** **_POST MI_** **HIGH CORONARY RISK** **HEART FAILURE**

* *_BETA BLOCKERS_** - olols

**What Drug based on MOA?** **_*Inhibits action of* RENIN_** Angiotensinogen --/--\> Angiotensin 1 ↓**AT1** ↓**AT2** **↓Aldosterone**

**_Direct RENIN Inhibitors_** **ALISKIREN / REMIKIREN**

**Diuretics as AntiHypertensives Clinical Effects** Thiazide + K-sparing Diuretics

* *BP = CO** x **PVR****CO = HR x SV** * *P**eripheral **V**ascular **R**esitance Initially diuretics (ACUTE): ↓**Blood Volume** ↓**CO** , while ↓**Na+ stores**, ↑**PVR** *may increase* After 6-8 weeks: **Na+ depletion --\> ↓PVR** and **CO returns to NORMAL**

**Compelling Indications for ARBS**

**_CKD_** **_DIABETES_**