Diuretics

Mechanism of Action

• Most diuretics alter renal function, causing an increase in the excretion of fluid.

Treatment

• Hypertension
• Heart Failure
• Edema (swelling)
• Certain kidney disorders

Use / Abuse in Sports and Exercise

• Rapid weight loss (Caldwell 1987)
  • Achieve a weight category
• Evading drug testing (Bahrke 2002)
  • Diuretics increase urine volume and dilute drug metabolites

Effect at Rest

• Decrease of blood pressure
• Decreased blood volume (Peel 1995)

Effects during Exercise

• May decrease blood pressure
  • May affect congestive heart failure patients
• May induce arrhythmias
• Healthy Individuals
  • Decreased exercise tolerance in direct proportion to the degree of hypohydration induced (Caldwell 1987)
• Clinical setting with compromised cardiopulmonary function (Caldwell 1987)
  • Increases exercise tolerance and decrease symptoms

Loop Diuretic

• Commonly used to treat edematous states
• Loop diuretics are inappropriate for the treatment of hypertension in competitive athletes and other physically active patients (Niedfeldt 2002)

Loop Diuretic Names

• Furosemide (Lasix)
• Bumetanide (Bumex or Burinex)
• Ethacrynic acid, Etacrynic acid (Edecrin)
• Torasemide, Torsemide (Demadex, Diuver, and Examide)

Potassium-sparing Diuretics

• Spironolactone (Aldactone)
• Amiloride (Midamor)
• Triamterene (Dyrenium)
  • Used in combination with thiazide diuretics for the treatment of hypertension and edema
    • Triamterene & Hydrochlorothiazid (Maxzide, Dyazide)

Carbonic Anhydrase Inhibitor

• Acetazolamide
  • The only Carbonic Anhydrase Inhibitor with significant diuretic effect (Kassamali 2011)
  • Can correct significant metabolic alkalosis which occasionally occurs with loop diuretic therapy (Kassamali 2011)
  • Prevents or improves symptoms of acute mountain sickness, thereby improving exercise performance at high altitude (Caldwell 1987)

Thiazide and Thiazide-like Diuretics

• Chlorothiazide (Diuril)
• Chlortalidone or Chlorthalidone
• Hydrochlorothiazide (Hydro-Diuril, Esidrix, Apo-hydro, Microzide)
• Triamterene & Hydrochlorothiazide (Maxzide, Dyazide)

Thiazide Diuretics Effect on Exercise

• No effect on heart rate (Niedfeldt 2002)
• Decrease in stroke volume (Niedfeldt 2002)
• Decrease in cardiac output (Niedfeldt 2002)
• Decrease in vascular resistance (Niedfeldt 2002)
• Decrease in plasma volume (Niedfeldt 2002)
• No effect on endurance (Niedfeldt 2002)

Potential Side Effects

• Orthostatic (postural) hypotension (Caldwell 1987, Niedfeldt 2002)
• Hypohydration (Caldwell 1987)
  • Adverse effects on performance
  • Impaired strength, power and endurance
• Urinary loss of potassium and magnesium (Niedfeldt 2002)
  • Could lead to muscle cramps, arrhythmias, and rhabdomyolysis in patients exercising intensely or competing in warm weather
• Hypovolemia (decreased blood volume) (Niedfeldt 2002, Boron 2004)
  • Diuretics
    • Loop diuretics (Boron 2004)
    • Thiazides (Boron 2004)
    • Not an issue with diuretics interfering with the aldosterone mechanism in the distal nephron (Caldwell 1987)
  • Symptoms (Boron 2004)
    • Fatigue
    • Thirst
    • Muscle cramps
    • Hypotension
  • May affect (Caldwell 1987)
    • Cardiac rhythm
    • Muscle function and integrity
    • Local blood flow
    • Carbohydrate metabolism
    • Blood lipid profile
  • Precautions (Caldwell 1987)
    • Diet may help to some degree
    • Potassium chloride supplements or potassium-sparing diuretics or diuretic combinations may be necessary
• Hypokalemia (low blood potassium) (Caldwell 1987, Boron 2004)
  • Diuretics (Boron 2004)
    • Acetazolamides
    • Loop diuretics
    • Thiazides
  • Symptoms (Boron 2004)
    • Muscle weakness
    • Paralysis
    • Arrythmia
• Hyperkalemia (high blood potassium) (Boron 2004)
  • Diuretics
    • Potassium-sparing Diuretics
  • Symptoms
    • Arrhythmia
    • Muscle cramps
    • Paralysis
• Hyponatremia (low blood sodium) (Boron 2004)
  • Diuretics
    • Furosemide (Lasix)
    • Thiazides
  • Symptoms
    • Nausea and vomiting
    • Headache
    • Confusion
    • Fatigue
    • Restlessness and irritability
    • Muscle weakness, spasms or cramps
    • Seizures
    • Coma
• Metabolic Alkalosis (low hydrogen ion concentrations) (Boron 2004)
  • Diuretics
    • Loop diuretics
    • Thiazides
  • Symptoms
    • Arrhythmia
    • Hand tremor
    • Lightheadedness
    • Muscle twitching
    • Nausea
    • Vomiting
    • Numbness or tingling in the face, hands, or feet.
    • Tetany (prolonged muscle spasms)
    • Confusion
    • Stupor or coma
• Metabolic Acidosis (high hydrogen ion concentrations) (Boron 2004)
  • Diuretics
    • Acetazolamides
    • Amiloride (Midamor)
    • Triamterene (Dyrenium)
  • Symptoms
    • Kussmaul respirations
    • Muscle weakness
    • Lethargy
    • Seizures
    • Stupor
    • Coma
• Hypercalcemia (high blood calcium) (Boron 2004)
  • Diuretics
    • Thiazides
  • Symptoms
    • Fatigue
    • Depression
    • Confusion
    • Anorexia
    • Nausea
    • Vomiting
    • Constipation
    • Increased urination
    • Pancreatitis
    • Gout
    • Tissue calcification
• Hyperuricemia (high blood uric acid) (Boron 2004)
  • Diuretics
    • Thiazides
    • Loop Diuretics
  • Symptoms
    • Gout

Recommended Population

• Elderly (Niedfeldt 2002)
• Black (Niedfeldt 2002)
• Those with congestive heart failure (Niedfeldt 2002)

Populations Not Recommended

• Endurance athletes (Niedfeldt 2002)
• Collegiate athletes (Niedfeldt 2002)

Banned Status

• Banned by USOC and NCAA

References

Boron WF (2004). Medical Physiology: A Cellular And Molecular Approach. Elsevier/Saunders. 875.

Bahrke Ml (2002). Performance-Enhancing Substances in Sport and Exercise. Human Kinetics.

Caldwell JE (1987). Diuretic therapy and exercise performance. Sports Med. 4(4):290-304.

Kassamali R, Sica DA (2011). Acetazolamide: a forgotten diuretic agent. Cardiol Rev. 19(6):276-8.

Niedfeldt MW (2002). Managing Hypertension in Athletes and Physically Active Patients. Am Fam Physician. 1;66(3):445-453.

Peel C, Mossberg KA (1995). Effects of exercise medications on exercise responses. Phys Ther;75(5):387-96.