Prescription for Hydrochlorothiazide?
25 mg
One tablet daily
Do not Abbreviate
What are the thiazide diuretic agents?
- Hydrochlorothiazide
- Chlorothiazide
Where do the thiazide diuretics work?
o Distal convoluted tubule Sulfonamide molecule • Worry about allergies to sulfur drugs Cells impermeable to water 10% sodium reabsorption • Na+/Cl- transporter sensitive to thiazides •
Indication for Hydrochlorothiazide?
Management of mild-to-moderate hypertension
Treatment of edema in heart failure and nephrotic syndrome
Indication for Chlorothiazide?
Management of hypertension
Adjunctive treatment of edema
Indication for Methyclothiazide?
- Management of hypertension
- Adjunctive therapy of edema
What are the “Ceiling” diuretics for the thiazide diuretics?
Increasing the dose beyond the normal dose does not increase diuretic effect
What are the effects for the thiazide diuretics?
o Increased excretion of sodium and chloride o Loss of potassium o Loss of magnesium o Decreased urinary calcium excretion o Reduced peripheral vascular resistance
What are the kinetics for the thiazide diuretics?
o 1 to 3 weeks to produce a stable reduction in blood pressure lose plasma volume so BP drops
o Then theory is you get direct vasodilation of arterial smooth muscle for long-term control
What are the adverse drug reactions of the thiazide diuretics?
o Hyponatremia (rare) Hypovolemia leading to increase in ADH, diminished diluting capacity of kidney and increased thirst Limit water intake and use lower doses o Hyperuricemia gouty arthritis o Volume depletion Orthostatic hypotension, dizziness o Hypercalcemia o Hypersensitivity Very rare- bone marrow suppression, dermatitis, necrotizing vasculitis, interstitial nephritis o Hyperglycemia Elevated blood glucose levels- harm or hype o Hyperlipidemia Elevated TC, LDL – harm or hype o Hypokalemia How low will I go? o NEED to get BMP on regular basis to check electrolytes (usually not a big deal though) o
What is the main thiazide-like diuretic?
• Chlorthalidone
o Long duration of action
Info about Metolazone?
- More potent than the thiazides
* Causes sodium excretion even in advanced renal failure
Info about Indapamide?
• Low doses- significant antihypertensive effect with minimal diuretic effect
• Gastrointestinal tract excretion- less likely to accumulate in patients with renal failure
•
Prescription for Chlorthalidone?
50 mg
One tablet daily
What was Chlorthalidone noted as ?
Chlorthalidone noted as superior to other agents such as lisinopril, amlodipine or doxazosin
When may the addition of a thiazide to a loop diuretic be helpful?
refractory edema in heart failure, cirrhosis, nephrotic syndrome and renal failure
What are the loop diuretics?
- **Furosemide
- Bumetanide
- Torsemide
Prescription for Furosemide?
40 mg
One tablet twice a day
Where/how do the loop diuretics work?
o Ascending Loop of Henle Sulfonamide molecule Cells impermeable to water 25 to 30% sodium reabsorption • Na+/K+/2Cl- cotransporter
- “High-ceiling diuretics
What are the effects of the loop diuretics?
o Increased excretion of sodium and chloride
o Loss of potassium
o Loss of magnesium
o Increased urinary calcium excretion
o Hypocalcemia avoided as most calcium reabsorbed in distal convoluted tubule
o Reduced renal vascular resistance/ increased renal blood flow
o Result of increased prostaglandin synthesis from loop diuretic use
What is the Diff in IV to PO for furosemide?
~ 50% bioavailability compared to the others, so if 40 mg IV is good, must give 80 mg oral on DC
Indications for furosemide?
Management of edema associated with heart failure and hepatic or renal disease
Acute pulmonary edema
Treatment of hypertension (alone or in combination with other antihypertensives)
Indications for Bumetanide (Bumex™)?
Management of edema secondary to heart failure or hepatic or renal disease (including nephrotic syndrome)
Indications for Torsemide (Demadex™)?
Management of edema associated with heart failure and hepatic or renal disease (including chronic renal failure)
Treatment of hypertension
