Drugs used for treatment of Hypertension 3 Flashcards
what does diuretics do and act where?
Diuretics act on
various sites in the
nephron to cause
diuresis (increase in
urine production)
Diuretics affects reabsoption and excretion of which ions
Affect reabsorption
and/or excretion of
Na+, K+, Mg2+,Ca2+, Cl-,
HCO3
-,
Site action of Thiazide diuretics
early DCT
The thiazide diuretic inhibits which symporter
Inhibit the Na+, Cl-, symporter
Thiazide diuretic increases and decreases extretion of which ions
Increase, Na+, K+, Mg2+ excretion
and decrease Ca2+excretion
greater volume of——————enriched tubular fluid to the late DCT and collecting ducts
NaCL
Explain the mechanisms of Action of thiazide diuretics
Antihypertensive actions of thiazide diuretics. Initially, thiazide diuretics
decrease blood volume and thereby decrease cardiac output. Over time, the
drugs decrease peripheral vascular resistance (PVR), an action that may be
secondary to a reduction in the sodium content of smooth muscle cells
cheap (cost-effective) drugs
Thiazide diuretics
Explain the initial treatment of thiazide diuretics
Initial treatment of mild to moderate hypertension, though recent clinical
trials suggest that an angiotensin inhibitor or calcium channel blocker (CCB)
may be preferable because of the superior ability of these agents to control
blood pressure for the entire day, and because they tend to cause fewer
adverse effects.
Thiazide diuretics use in combinations with which drugs in order to do what?
Thiazide diuretics are also used in combination with other types of
antihypertensive agents, because they have additive or synergistic effects
on blood pressure, and a diuretic may prevent the compensatory fluid
retention evoked by another agent.
The recent clinical shows that the combination of indapamide and an angiotensin inhibitor does what?
Recent clinical trials have shown that the combination of indapamide and
an angiotensin inhibitor effectively controls blood pressure while reducing
the risk of stroke and myocardial infarction in hypertensive patients.
Chemical name for thiazide diuretic
Sulpjonamide compounds
explain how thiazide diuretics are metabolised and secreted?
Partially metabolised before excretion in the urine
* Actively secreted into the nephron by proximal tubular cells, travel
through nephron lumen to reach site of action (distal convoluted
tubule)
Adverse effects for thiazide diuretics depends on what?
Dose-dependent adverse effects, but minimal increase in efficacy if
dose is increased
Thiaizide diuretics appears to offer proctection against what?
Appear to offer protection against osteoporosis (decrease urinary
excretion of calcium
explain the adverse effect of thiazide diuretic
- Dose-dependent (12.5mg versus 25 mg)
- Electrolyte (hypokalaemia, hypomagnesaemia, hyponatraemia,
hypochloraemic alkalosis) - Metabolic abnormalities: elevated glucose, uric acid and lipid levels
- Decreased insulin sensitivity and insulin secretion (hypokalaemia)
- Hyperuricaemia = decreased uric acid secretion from proximal tubule
(precipitate gout)
List 4 contra-indications for hydrochlorothiaizde
- Gout
- Pregnancy
- Severe liver impairment
- Kidney impairment (eGFR <30ml/min)
List the caution for hydrochlorothiazide
Caution in patient with family history of skin cancer – counsel on sun
avoidance and sun protection
Explain the MoA of Loop diuretics
Inhibit symporter that
transports Na+, K+,
2Cl- back into tubular
cells
Reduce back diffusion
of K+ and increase
excretion of Mg2+ and
Ca2+
Explain the potency of loop diuretics
- Exert a more powerful natriuretic effect than other diuretics, because
they inhibit the reabsorption of a greater percentage of sodium - High-ceiling diuretics – dose dependent effect
Indications for loop diuretics
- Oedema, pulmonary oedema
- Oedema secondary to heart failure, liver cirrhosis, etc.
