Thiazide diuretic

Question 1

What are the generic and brand names of thiazide diuretics?

Answer 1

• Bendrofumathiazide (Aprinox)

* Indapamide (Natrilix)

Question 2

What is the method of action of thiazide diuretics?

Answer 2

• Affects distil convoluted tubule of the nephron
• Blocks the Na+/Cl- co transporter
• Na+ isn’t absorbed and neither is water
• Short term only – renin angiotensin system will then takes over
• Vasodilates but method is not understood

Question 3

What are the indications for thiazide diuretics?

Answer 3

• Alternative first line treatment for hypertension e.g. if features of heart failure/odeama then Ca channel blocker cannot be used
• Add on treatment for hypertension – if Ca channel blocker plus ACE inhibitor/ARB doesn’t work

Question 4

What are the contraindications for thaizide diuretics?

Answer 4

• Hypokalaemia
• Hyponatraemia
• Gout

Question 5

What are the side effects of thiazide diuretics?

Answer 5

• Hyponatraemia
• Hypokalaemia = cardiac arrhythmias
• Increased plasma glucose
• Increased LDL’s
• Increased triglycerides
• Erectile dysfunction

Question 6

What drug interactions occur with thiazide diuretics?

Answer 6

• NSAIDs – thiazide effect reduced (low dose aspirin not included)
• Loop diuretics – lowers potassium too

Question 7

How are thiazide diuretics excreted?

Answer 7

Kidney

Question 8

What patient information should be given for someone on thiazide diuretics?

Answer 8

• Will cause more frequent urination

* Avoid NSAIDs