Hypertension Flashcards
Hypertension definition
Defined as two elevated blood pressures on two or more visits
Systolic >140 mmHg
Diastolic >90 mmHg
HTN screening - how, when
Patients should be seated, comfortable with back and feet supported, arm supported at heart level
Adults should be screened at each visit
No recommendations for screening asymptomatic children
HTN Exam includes:
Exam should include
Heart and lung sounds
Orthostatics (especially if on medication, elderly)
Neuro exam
Fundoscopic exam
Peripheral vascular exam (check for bruits, peripheral pulses)
HTN Labs:
Diagnostics
ECG
Labs: CBC, BMP, LFTs, Lipids, TSH, UA
How is BP usually mediated via meds?
Must understand how blood pressure is mediated to prescribe medications
Most patients require 2 medications for blood pressure control, need to understand how medications can work together
Name 5 mechanisms/ etiologies of HTN
Mechanisms of hypertension Hypervolemia Na retention Increased cardiac output Tachycardia Increased vascular tone
Major changes from JNC VIII?
Major changes in JNC VIII
More evidenced based as opposed to expert opinion
Less stringent guidelines for BP in patients 65-79 y/o
Thresholds for initiating pharmacologic treatment
Can start with multiple classes of medicatons
Stages of HTN
Normal:
PREHTN:
HTN, STAGES:
I
II
Types of HTN and etiologies
Primary
Most common
No identifiable cause or cure
Secondary
Caused by drug, disease, or other identifiable cause
Oral contraceptives, cocaine or other stimulant abuse, pheochromocytoma, sleep apnea, thyroid disease
Curable once cause is identified
Common side effects of HTN
Some common side effects:
All can cause headache, dizziness, syncope, hypotension
Monitoring parameters
Common monitoring parameters:
Blood pressure, most need BMP
Name the 7 general (broad) categories of HTN RX choices:
- Diuretics
- Beta-Blockers (“Sympatholytics”)
a) alpha 2 agonists
b) alpha 1 ANTAGONISTS
c) beta 1 ANTAGONISTS
d) mixed alpha/beta ANTAGONISTS - Vasodilators
- Calcium Channel Blockers
- Angiotensin Converting Enzyme Inhibitors
- Angiotensin Receptor Blockers
- Renin Inhibitors
Name the 3 types of Diuretics
- Thiazide
- K+ sparing
- Loop
Thiazide Diuretics: Names, MOA
Hydrochlorothiazide, chlorthalidone Developed in the late 1950’s, one of the oldest class of antihypertensives Mechanism of action: inhibits Na reabsorption in distal renal tubule causing increased H2O, as well as Na, K, and H Decreased circulating volume = lower bp
Thiazide Diuretics: Pharmacokinetics
Pharmacokinetics Good PO absorption Causes diuresis in approximately 2 hours, antihypertensive effects seen in 3-4 days Up to 68% protein bound Not metabolized Excreted in urine as unchanged drug
**Important! THINK when someone is on a THIAZIDE… what are you concerned about (monitoring)?
Electrolyte imbalances/ monitor BMP!
Get a BMP at initiation of RX and periodically
Side effects of Thiazides:
Side effects: hypokalemia, hypomagnesmia, pancreatitis, hyperglycemia, phototoxicity
**Emphasis of MOA for Thiazides
Decreased circulating volume = lower bp
**Emphasis of timing to take meds
Take in AM because…
Causes diuresis in approximately 2 hours, antihypertensive effects seen in 3-4 days
Contraindications for Thiazides:
anuria, sulfa allergy
Pregnancy category for Thiazides, indications for BFEED and PEDS?
Safe in pregnancy (category B), excreted in breast milk but safe in breastfeeding (might decrease milk production though), safe in pediatrics
K+ Sparing Diuretics: names and MOA
Spironolactone (Aldactone), Triamterene (Dyrenium)
Mechanism of action: competitively binds to aldosterone-dependent Na/K exchange site in distal convoluted tubule, causing increased H2O excretion (S); directly blocks Na reabsorption in distal renal tubule (T)
**K+ Sparings: emphasis on monitoring K+
while K+ sparing diuretics have no impact on lowering the K+, there can be an INCREASED K+ so watch out!
K+ Sparing: pharmacokinetics
Pharmacokinetics Well absorbed PO (~70% bioavailibility) VERY protein bound (90%, spironolactone; 67% triamterene) Metabolized in liver and kidneys Excreted in both urine and stool
K+ Sparing: monitoring parameters
BMP
K+ Sparing: adverse effects
Adverse effects: rash, photosensitivity, thrombocytopenia, Stevens-Johnson Syndrome
K+ Sparing: because they are highly PROTEIN BOUND…. WHO are you most worried about taking this type of diuretic?
VERY protein bound (90%, spironolactone; 67% triamterene)
SO in liver disease, when they are not producing enough circulating proteins for the drug to bind….
worry about TOO MUCH FREE DRUG ie TOXICITY!
K+ Sparing: Contraindications:
Contraindications: anything that can cause hyperkalemia (Addison’s disease), anuria, liver disease
K+ Sparing Pregnancy category/ BFEED/ PEDS?
Safe in pregnancy (category B), excreted in breast milk but safe in breastfeeding (might decrease milk production though), safe in pediatrics
K+ Sparing Pregnancy category/ BFEED/ PEDS?
Category C in pregnancy, not for use in breastfeeding, off label in pediatrics
Diuretics: Loop- name, MOA
Furosemide (Lasix), torsemide (Demedex)
Not great antihypertensives, NOT first line
Mechanism of action: inhibits Na and Cl reabsorption in proximal and distal tubules and loop of henle
**Emphasis: Loops are NOT first line for HTN but usually seen with…
CHF
**Emphasis: Loop diuretics are selective: YES OR NO and why is this important?
Loop diuretics are NOT selective, so….
WATCH THE K+! MONITOR BMP!
Loop Diuretics: Pharmacokinetics
Pharmacokinetics
Good PO absorption (64% bioavailability)
VERY protein bound (99%)
Metabolized in liver, excreted in urine
Loop Diuretics: monitoring parameters
Monitoring parameters: BMP (especially K) but also Ca, Mg
Loop Diuretics: Adverse Effects
Adverse effects: muscle cramps, glucose intolerance, rash, gout
** Emphasis- Loop Diuretics: pregnancy categories/ BFEED/ PEDS?
Furosemide is C in pregnancy, torsemide B; do not use either in lactation, torsemide not approved in pediatrics
Sympatholytics- Beta Blockers- name 2 centrally-acting alpha-2 agonists
- Clonidine (Catapres)
2. Methyldopa (Aldomet)
Clonidine (Catapres) - MOA and PK
Mechanism of action: alpha-2 agonist in CNS, decreasing sympathetic outflow ( HR, vascular tone = BP)
Pharmacokinetics
Well absorbed PO (85% bioavailibility)
Metabolized in liver, excreted in urine
Clonidine (Catapres)- side effects and contraindications
Side effects: dry mouth, anxiety, constipation, rash, abnormal LFTs
Contraindications: rash
Clonidine (Catapres) - monitoring parameters
Monitoring Parameters: LFTs
**Emphasis: Clonidine (Catapres) - pregnancy category, BFEED/ PEDS?
Safe in pregnancy, not recommended in breastfeeding, approved for use in pediatrics >12 y/o
Methyldopa (Aldomet)- MOA and PK
BASIC WAY TO SAY IT: AFFECTS CASCADE OF EVENTS
Mechanism of action: Alpha 2 agonist in CNS, which decreases sympathetic outflow ( HR, vascular tone = BP); also a competitive inhibitor of DOPA decarboxylase, which converts L-DOPA to dopamine, a precursor to norepi and epi, so less norepi/epi, less adrenergic effects.
Pharmacokinetics
Well absorbed PO (50% bioavailability)
Minimal protein binding
Mretabolized in liver, excreted in urine (small amount in stool)
Methyldopa (Aldomet)- side effects and contraindications
Side Effects: depression, anxiety, parkinsonism (because of antidopaminergic effects); hyperprolactinemia, gynecomastia, rash, hemolytic anemia
Contraindications: liver disease, concomitant use of MAOIs, pheochromocytoma
**Emphasis- Methyldopa (Aldomet) - because of these side effects, what other diseases in a pt can be affected?
Be careful with Psych and Parkinson’s pts because of the antidopaminergic affects/ parkinsonism side effects
Methyldopa (Aldomet)- monitoring parameters
Monitoring parameters: CBC, LFTs
