Antihypertensives Flashcards
1
Q
Hydrochlorothiazide: Brand name, others in class
A
HydroDiuril
Chlorthalidone, 5 others
2
Q
Hydrochlorothiazide: Drug class
A
Pharmacologic: thiazide diuretic
Therapeutic: diuretic, antihypertensive
3
Q
Hydrochlorothiazide: Pharmacodynamics (5)
A
Block reuptake of CL and NA fron tubular fluid after glomerular filtration
Appears to cause decrease in SVR via unclear mechanism
Lowers BP up to 10-15mmHg in many pts
Useful as monotherapy or in combinations
Chlorthaladone may be slightly better
4
Q
Hydrochlorothiazide: Pharmacokinetics (5)
A
F ~70% Excreted unchanged in urine Short half life (hours) Not available in IV formulation Onset 2h, peak 5h, duration 10h
5
Q
Hydrochlorothiazide: Toxicity (5)
A
Allergy to sulfa Abx Cause K and Mg depletion Cause Na and Cl depletion, metabolic alkalosis Volume depletion Worsen hyperuricemia
6
Q
Hydrochlorothiazide: Interactions
A
Additive effects with most other antihypertensives
7
Q
Hydrochlorothiazide: Special considerations (3)
A
More side effects in geriatric patients
Pregnancy Class D
Much less effective in pts with reduced GFR
8
Q
Hydrochlorothiazide: Indications/dose/route (2)
A
12.5mg or 25mg po every morning
Little benefit, more toxicity when given in higher doses
9
Q
Hydrochlorothiazide: Monitor (7)
A
BP, weight, edema, K, Mg, BUN, creatinine
10
Q
Lisinopril: Brand name (2), others in class (3)
A
Prinivil, Zestril
Captopril, enalapril, ramipril (total of 10)
11
Q
Lisinopril: Drug class (6)
A
Pharmacologic: ACE inhibitor
Therapeutic: antihypertensive, treatment of CHF, preserving renal function, preserving LV function after MI, acute management of MI
12
Q
Lisinopril: Pharmacodynamics (2)
A
Inhibits conversion of AT I to AT II by ACE
Diminishes both vasoconstriction and stimulation of aldosterone secretion by AT II
13
Q
Lisinopril: Pharmacokinetics (4)
A
Well absorbed
Onset 1h, peak 6h, duration 24hr
Once a day is fine
Excreted primarily in urine as unchanged drug
14
Q
Lisinopril: Toxicity (5)
A
Orthostatic hypotension
Use with caution in pts with impaired renal function or RAS (dilates efferent arteriole!)
Caution in pts on diuretics or with aortic stenosis
Angioedema, cough
Acute renal failure
15
Q
Lisinopril: Interactions (3)
A
Additive effects with most other antihypertensives
NSAIDs may reduce ability to lower BP
Hyperkalemia with KCl, others
16
Q
Lisinopril: Special considerations (2)
A
Often discontinue diuretics prior to beginning use to reduce hypotension
Category C/D in pregnancy, abnormal cartilage development
17
Q
Lisinopril: Indications/dose/route
A
Begin 10mg/day, titrate slowly up to 40mg/day max
18
Q
Lisinopril: Monitor (6)
A
BP, weight, edema, K, BUN, creatinine
19
Q
Losartan: Brand name
A
CoZaar
7 others in class
20
Q
Losartan: Drug class (4)
A
Pharmacologic: angiotensin-1 receptor blocker (ARB)
Therapeutic: Antihypertensive, preserve renal function, treatment of CHF
21
Q
Losartan: Pharmacodynamics
A
Block stimulation of ATI receptor by ATII, thereby reducing vasoconstriction and production of aldosterone
22
Q
Losartan: Pharmacokinetics (4)
A
F ~30%
Onset 6h
Extensive first pass effect
Active metabolite 40x more potent, much longer half-life
23
Q
Losartan: Toxicity (3)
A
Dizziness
Orthostatic hypotension
Worsening of renal failure
24
Q
Losartan: Interactions
A
Additive effects with most other antihypertensives
25
Losartan: Special Considerations (2)
```
Pregnancy class C/D
Use care in pts on diuretics, with RAS, or mitral or aortic stenosis
```
26
Losartan: Indications/dose/route
For HTN, daily doses 25-100mg q day
27
Losartan: Monitor (6)
BP, weight, edema, electrolytes, BUN, creatinine
28
Nitroprusside: brand name (2)
Nipride, Nitropress
29
Nitroprusside: Drug class (5)
Pharmacologic: vasodilator
Therapeutic: antihypertensive, management of severe CHF, management of pulmonary HTN, produce controlled hypotension to reduce bleeding during surgery
30
Nitroprusside: Pharmacodynamics (3)
Acts directly on vascular SM to cause dilation of both veins and arterioles
Metabolized to release CN- and NO, which -> guanylate cyclase -> production of cGMP from GTP -> vasodilation
cGMP then hydrolyzed to GMP by PDE
31
Nitroprusside: Pharmacokinetics (4)
Only route is IV
Rapid onset and cessation (minutes) -> minute-to-minute titration
CN- metabolite converted to SCN in liver, then excreted in urine
Must be given by continuous infusion, no longer than 24 hours
32
Nitroprusside: Toxicity (4)
Excessive hypotension
Accumulation of CN- and thiocyanate
Headache
Decreased blood flow to brain
33
Nitroprusside: Interactions
Additive effects with most other antihypertensives
34
Nitroprusside: Special considerations (3)
Monitor pts VERY closely - must be in ICU with arterial line, no longer than 24 hrs
Avoid high infusion rates or prolonged infusions to prevent accumulation of CN-
Use caution in pts with increased intracranial pressure
35
Nitroprusside: Indications/dose/route
For treatment of hypertensive crisis, given as IV infusion at 0.3-10mcg/kg/min, NO longer than 24 hours
36
Nitroprusside: Monitor (4)
BP, HR, metabolic acidosis
| Most often requires arterial line
37
Hydralazine: Brand name
Apresoline
38
Hydralazine: Drug class (4)
Pharmacologic: peripheral vasodilator
Therapeutic: antihypertensive, treatment of CHF, vasodilator
39
Hydralazine: Pharmacodynamics (3)
Direct acting vasodilator
Induces endothelium to produce NO (different from nitroprusside), which then -> to SM cells and -> production of cGMP
Minimal venodilating effect
40
Hydralazine: Pharmacokinetics (6)
Given po, im, iv
Metabolized extensively in GI mucosa and in liver
Eventually excreted as metabolites in urine
F ~40%
Onset 30 after po dose, 10 min after iv dose
Persist for 2-6 hours
41
Hydralazine: Toxicity (2)
More dangerous in pts with renal disease, prior stroke, angina
Watch for hypotension, edema, occasionally drug-induced lupus
42
Hydralazine: Interactions
Additive effects with most other antihypertensives
43
Hydralazine: Special considerations (2)
Never use as chronic oral monotherapy for treatment of HTN, will -> edema, reflex tachycardia (rarely used today except for final month of pregnancy with extreme HTN)
Concern giving to patients with CAD
44
Hydralazine: Indications/dose/route
Dose 10-50 mg po 4x/day
45
Hydralazine: Monitor (6)
BP, weight, edema, BUN, creatinine, symptoms of lupus or angina
46
Verapamil: Brand name (2), others in class (4)
Isoptin, Calan
| Others: nifedipine, amlodipine, diltiazem, nicardipine (total 8)
47
Verapamil: Drug class (3)
Pharmacologic: Ca entry blocker
Therapeutic: antihypertensive, antianginal, antiarrhythmic
48
Verapamil: Pharmacodynamics (5)
Reduces BP by inhibiting influx of Ca through slow channels, -> dilating peripheral arterioles
Produces negative inotropic effect
**Angina: reduces afterload, decreasing oxygen consumption
Inhibits spasm of coronary arteries in vasospastic angina
Blocks reentry paths through AV nodes in paroxysmal SVT
49
Verapamil: Pharmacokinetics (6)
```
Absorbed rapidly, but F ~30%
Also available in SR tablets
Cleared by kidney and liver (produces active metabolites
Onset 2h po, 1-5 min IV
Half life 6-12h
May be given po or IV
```
50
Verapamil: Toxicity (4)
Hypotension, AV block, worsening of CHF, bradycardia
51
Verapamil: Interactions (2)
Additive effects with most other antihypertensives
| Additive toxic effects on heart when given with beta-blockers
52
Verapamil: Special considerations (3)
Use reduced dose in pts with both renal and hepatic disease
Short-acting nifedipine (and similar CEBs) can increase risk of MI
Pregnancy C
53
Verapamil: Indications/dose/route
80 mg 3x/day, or 240mg SR once daily
54
Verapamil: Monitor (3)
Weight, edema, BP
55
Clonidine: Brand name, others in class (1)
Catapres
| Other: Methyldopa
56
Clonidine: Drug class (3)
Pharmacologic: central alpha-2 agonist
Therapeutic: antihypertensive, adjunct to Rx of opioid withdrawal, prophylaxis of migraine
57
Clonidine: Pharmacodynamics
Stimulates alpha-2 adrenoceptors in brainstem -> down-regulation of sympathetic output
58
Clonidine: Pharmacokinetics (3)
Onset 1h, duration 8h
F ~ 85%
Also available as cutaneous patch
59
Clonidine: Toxicity (3)
Withdraw gradually because of risk of rebound HTN
Risk of bradycardia in sinus node disease
Lethargy, fatigue, depression
60
Clonidine: Interactions (2)
Additive effects with most other antihypertensives
| Additive sedation with other CNS drugs
61
Clonidine: Special Considerations (2)
```
Pregnancy class C
Avoid in pts with renal insufficiency
```
62
Clonidine: Indications/dose/route
Begin with 0.1mg po bid, up to 1.2mg per day
| Transdermal: begin with 0.1mg per 24 hr as a 7 day patch
63
Clonidine: Monitor (3)
BP, HR, fatigue
64
Trimethaphan: Brand name, others in class
Arfonad
| No others in class
65
Trimethaphan: Drug class
Pharmacologic: ganglionic transmission blocker
Therapeutic: antihypertensive (acute, by IV)
66
Trimethaphan: Pharmacodynamics (2)
Blocks nicotinic transmission within both sympathetic and parasympathetic ganglia (Nn receptors)
Produces veno- and vasodilatation
67
Trimethaphan: Pharmacokinetics (3)
Useful only when given IV
Produces fall in BP within minutes
Partly metabolized, partly excreted by kidneys
68
Trimethaphan: Toxicity (3)
Watch for sudden, severe drop in BP
Fall in HR
Reduction in just about any sympathetic or parasympathetic response
69
Trimethaphan: Interactions
Additive effects with most other antihypertensives
70
Trimethaphan: Special considerations (2)
Pts miserable, only used during general anesthesia
| Helps to tilt pt to help control BP
71
Trimethaphan: Indications/dose/route
Give by IV infusion to treat HTN crisis, or for controlled hypotension during cardiovascular surgery
72
Trimethaphan: Monitor (2)
Minute to minute monitoring of BP and HR
73
Reserpine: Brand name, others in class
No brand name
74
Reserpine: Drug class
Pharmacologic: Rauwolfia alkaloid
Therapeutic: Antihypertensive
75
Reserpine: Pharmacodynamics (3)
Binds to vesicles that contain NE OR serotonin, preventing their uptake and depleting the neuron of NE or serotonin
Takes 2-3 weeks to deplete
Includes neurons and the adrenal medulla
76
Reserpine: Pharmacokinetics
Good oral bioavailability, but biologic effects take 2-3 weeks (slow depletion of NE/serotonin from vesicles)
77
Reserpine: Toxicity (3)
Dizziness
Orthostatic hypotension
Depression!!! (NOT used today!)
78
Reserpine: Interactions
Additive effects with most other antihypertensives
79
Reserpine: Special considerations (2)
FDA approved in 1953
| First antihypertensive drug + first sympatholytic drug approved
80
Reserpine: Indications/dose/route
For HTN, 0.1-0.2mg po qd
81
Reserpine: Monitor (3)
BP, sympathetic tone, depression
82
Atenolol: Brand name, others in class (2)
Tenormin
| Others: Propranolol, metoprolol (Toprol XL)
83
Atenolol: Drug class (4)
Pharmacologic: beta-adrenoceptor blocker (beta-1 specific)
Therapeutic: antihypertensive, antiarrhythmic, primary and secondary prevention of MI, anti-anginal
84
Atenolol: Pharmacodynamics (2)
Binds directly to beta-receptors (beta-1 >> beta-2) -> lower BP via several mechanisms (lower CO, lower RAAS activation)
Less effective in preventing strokes than other drugs, so used less often as initial monotherapy
85
Atenolol: Pharmacokinetics (5)
```
Available po or IV
Variable oral F
Onset 1-2h, duration 12-24h
Can be given once per day
Renally excreted (longer half life)
```
86
Atenolol: Toxicity (4)
Excessive hypotension
Bradycardia
Heart block can worsen CHF if severe (but good for mild to moderate CHF)
Worsen bronchospasm in severe asthmatics
87
Atenolol: Interactions (2)
Additive effects with most other antihypertensives
| Additive AV block with CEBs
88
Atenolol: Special considerations (3)
May be especially useful in HTN pts with exertional angina, MI, a. fib
Watch out for abrupt withdrawal
No longer first line drug unless other indications exist
89
Atenolol: Indications/dose/route
For treatment of HTN, 25-100 mg per day, in one or two doses
90
Atenolol: Monitoring (3)
BP, HR, exercise tolerance
91
Prazosin: Brand name, others in class (3)
Minipress
| Terazosin, doxazosin, tamsulosin
92
Prazosin: Drug class (4)
Pharmacologic: alpha-1 adrenoceptor blocker
Therapeutic: Antihypertensive, treatment of BPH, treatment of Raynaud's syndrome, treatment for kidney stones
93
Prazosin: Pharmacodynamics
Blocks alpha-1 receptors on arterioles and veins, thereby inhibiting NE-mediated vasoconstriction and venoconstriction
94
Prazosin: Pharmacokinetics (4)
Available po or transdermal
Variable oral bioavailability (~60%)
Onset 2h, duration 12-24h
Extensively metabolized in liver
95
Prazosin: Toxicity (3)
Excessive hypotension with passing out, especially orthostatic, especially in pts on diuretics
96
Prazosin: Interactions
Additive effects with most other antihypertensives, especially diuretics
97
Prazosin: Special considerations (2)
Start gradually at bedtime to avoid first-time passing out
| Male pts with BPH?
98
Prazosin: Indications/dose/route
As monotherapy, begin with 1mg tid, advance to 20mg per day divided tid
99
Prazosin: Monitor (3)
BP, weight, edema
100
Labetalol: Brand name, others in class
Trandate
| Others (KNOW): Carvedilol/Coreg(tm)
101
Labetalol: Drug class (2)
Pharmacologic: Alpha and beta receptor blocker
Therapeutic: Antihypertensive, treatment of CHF
102
Labetalol: Pharmacodynamics (2)
Reduces BP by blocking access of NE to beta-receptors and alpha-1 receptors -> lowering BP by several different mechanisms
Pts differ in degree of beta- vs alpha-blockade
103
Labetalol: Pharmacokinetics (3)
Excellent absorption but high first pass effects (F~25%)
Onset 1-2h po, 2-5min IV
Extensively metabolized in liver by IID6
104
Labetalol: Toxicity (3)
```
Avoid in pts with bradycardia, heartblock, CHF, asthma, shock
Use caution in pts with cardiomyopathy, pheochromocytoma
Pregnancy class D
```
105
Labetalol: Interactions
Additive effects with most other antihypertensives
106
Labetalol: Special considerations (3)
Use reduced doses in pts with impaired liver function
Dizziness is most troubling early side effect
Most often used for hypertensive crisis (as with nitroprusside)
107
Labetalol: Indications/dose/route (2)
Most commonly given IV with initial small boluses of 20mg, followed by continuous infusion at 2mg/min
Not usually given po for chronic treatment (80mg tid or 240mg SR qd)
108
Labetalol: Monitor (2)
BP, HR
