DIURETICS

Diuretics cause diuresis, and the urinary frequency may be more of a burden to the person than the edema.

Prescribing a diuretic is one of the few occasions when a combination drug is helpful. For routine use a combination of a loop diuretic (potassium losing) and a potassium sparing diuretic is useful to avoid the need for potassium supplements.

Loop diuretics act within 60 minutes, and the diuresis lasts 4 to 6 hours.

For resistant edema, the dose may have to be increased to furosemide 80mg 2 times a day, or bumetanide 2mg 2 times a day (which is better absorbed), with spironolactone 200mg 2 times a day. (Amiloride and triamterene are weak diuretics and are not aldosterone antagonists.) Avoid IM injections which are poorly absorbed.

A very useful additional drug for resistant edema is metolazone 10mg to 20mg per day, in addition to high dose furosemide and spironolactone. It can often produce a diuresis when other drugs have ceased to be effective.

Problems with diuretics:

• Urinary frequency

• Disturbed sleep

• Urinary retention (if prostatic)

• Dry mouth

• Nausea (spironolactone)

• Hypokalemia

• Cramps (sodium loss)

• Dizziness (hypovolemia)

• Tinnitus (high dose furosemide)

• Rashes (amiloride, triamterene)

High dose spironolactone may be indicated for ascites. (see Ascites)

Leg swelling due to lymphedema responds poorly to diuretics. (see Lymphedema)

The author and publisher have taken precautions to ensure that the information in this book is error-free. However, readers must be guided by their own personal and professional standards of good practice in evaluating and applying recommendations made herein. The contents of this book represent the views and experience of the author, and not necessarily those of the publisher.