CENTRAL  SOUTH  DAKOTA  MEDICAL NEWS
THE CLINICAL VIEW
By: Phillip E. Hoffsten, M.D.
14 September 2006

 What is a Diuretic (water pill)?

It is interesting to consider how modern times have changed human beings basic needs. Today, if you want something to drink, there is everything from milk to juice to soda pop or water at the simple turn of your faucet. Recreational encounters involve drinking coffee or tea or punch or beer or wine or a host of other beverages. But, if one looks back through our history, thousands of years ago when our species evolved, fluids were not always available. Our distant ancestors did not have water faucets. The fluids they drank might be contaminated, and in times of drought, great hardship was encountered by our ancestors. Thus, those of our ancestors who survived and sired us where those with the best water-conserving systems. Their bodies were very efficient in conserving salt and water. That property was life saving for them but ironically can now become life threatening in modern society where water is so freely available.

 To better understand the problem, it first needs to be understood that there is a message system between the heart and the kidneys. For our ancestors, this was highly beneficial because when they became dehydrated and the amount of blood their heart could pump decreased, their heart sent a message to the kidneys saying save all the salt and save all the water because the body is getting dehydrated. The kidney dutifully put out very little urine at that point. Water and salt were conserved and the person survived. But, in today's world, when the heart pumps less blood it is most commonly because there is heart disease that our ancestors never lived long enough to develop. In as short of time as 100 years ago, the average life span was in the 50s. Now the average life span is in the 70s and with present trends will be in the 80s by 2010. Now, people live long enough to develop heart disease as opposed to being eaten by lions or tigers or bears as they did in the past. Now, when the heart pumps less blood, it is because the person has heart disease. The fluid retention system adapted from so many years ago becomes a part of the disease as opposed to a life saving mechanism.

 Now enters the concept of the water pill (diuretic). The person with heart disease sending their kidney a message saying save all the salt and save all the water, retains fluid and develops swelling in their ankles, often in their abdomen and in extreme situations in their lungs becoming very short of breath. With the recognition of this problem, medical science developed a medication called a diuretic that redirects the kidneys to excrete more salt and water thereby overriding the message from the failing heart. The symptoms of shortness of breath, the ability to sleep lying flat, and the swelling of the ankles that comes with heart problems can all be overcome with appropriate use of diuretics.

 As might be imagined, since the first diuretics were introduced 50 years ago, there are now multiple different types that can be used depending upon the person's individual need. By far the most commonly used diuretic is called furosemide (Lasix). This diuretic is the most potent and very economical to use. Doses as low as 20 mg per day may be used for individuals with mild fluid retention problems. Sometimes individuals with more intense fluid retaining states, may use hundreds of mgs of Lasix per day in order to maintain their bodies free of excessive fluid. The side effects from this medication are most commonly an over-effect causing too much fluid loss. This has to be monitored carefully between the health care provider and the patient to be sure that this type of problem does not develop. In addition, a potassium supplement usually needs to be added to the medical regimen in order to ensure that low serum potassiums do not occur.

 The second most common diuretic used is called hydrochlorothiazide which is one of the oldest diuretics on the market. This family of medications is not as potent as furosemide. The thiazide family of diuretics has the additional benefit of being an antihypertensive and is used for that purpose alone in some people. The thiazides are often used with furosemide to help patients who have extreme fluid retaining states. The side effects of the thiazide family of diuretics include an increased potassium loss, an elevation of uric acid sometimes causing gouty arthritis attacks and a tendency to unmask diabetes. An additional advantage of the thiazides is that they are also very cheap medications.

 There are three diuretics that are described as potassium sparing diuretics. These are relatively more expensive and less effective but do have the advantage of avoiding potassium loss in individuals where this is an important consideration. These three diuretics are called triamterene (found in Dyazide), amiloride (found in Moduretic), and spironolactone (found in Aldactone and Aldactazide). Spironolactone has the fringe benefit of preventing hair growth in women who sometimes have more facial hair than they find desirable. Spironolactone also has a very important benefit in prolonging longevity in patient's that have congestive heart failure as shown in recent studies.

An important point in care for individuals using diuretics is to avoid over-the-counter pain medications such as aspirin, ibuprofen (Motrin, Nuprin, Advil), Naprosyn (Aleve), and ketoprofen (Orudis). These medications interfere with the diuretic effect on the kidney and cause fluid retention all by themselves. Tylenol does not have such an effect and can be used in people using diuretics.

The proper use of diuretics and the avoidance of side effects can be worked out through the health care professionals at your local clinic.