Fichas
Diuretics (Thiazide and Thiazide-Like)
Fichas del conjunto (4)
- 1Give eg's of & indications for thiazide diuretics.eg's: indapamine, chortalidone, bendroflumethiazide
Indications:
• Alternative first-line Rx for HT where a calcium channel blocker is unsuitable (eg oedema) or there are features of HF
• Add-on treatment for HT where BP isn't being controlled by a calcium channel blocker plus an ACE inhibitor or an angiotensin blocker - 2MOA of thiazide diuretics.Thiazide diuretics (e.g. bendroflumethiazide) & thiazide-like diuretics (e.g. indapamide, chlortalidone) differ chemically but have similar effects and uses; we refer to them collectively as ‘thiazides.’ Thiazides inhibit the Na+/Cl− co-transporter in the distal convoluted tubule of the nephron. This prevents reabsorption of sodium and its osmotically associated water. The resulting diuresis causes an initial fall in extracellular fluid volume. Over time, compensatory changes (e.g. activation of the renin–angiotensin system) tend to reverse this, at least in part. The long-term antihypertensive effect is probably mediated by vasodilatation, the mechanism of which is incompletely understood.
- 3SE's of thiazide diuretics.• Hyponatraemia
• Hypokalaemia (may in turn lead to cardiac arrhythmias)
• Impotence - 4CI's, cautions, & important interactions of thiazide diuretics.CI's:
• Hypokalaemia
Cautions:
• Hyponatraemia
• Gout
Important interactions:
The effectiveness of thiazides may be reduced by NSAID's (although low-dose aspirin is not a concern). The combination of thiazides with other drugs that lower the serum potassium concentration (e.g. loop diuretics) is best avoided. If combination is essential, it should prompt intensive electrolyte monitoring.