Diuretics: Thiazide, Loop, and Potassium-Sparing

• Diuretics are a class of drugs.

Thiazide and Loop Diuretics

• Drugs include hydrochlorothiazide and furosemide.
• Indications are rapid and edema associated hypertension.
• Pathophysiology is edema.
• Action is to block chloride.
• Furosemide keeps chlorine, causing more sodium loss
• Both drugs are metabolized.
• Common adverse effects are related to fluid and electrolyte levels. Includes alkalosis, hypokalemia, and hypocalcemia.
• Contraindicated if more powerful than thiazide and loop diuretics.

Carbonic Anhydrase Inhibitors

• Drug is acetazolamide.
• Indicated for acute pulmonary edema associated with glaucoma.
• Pathophysiology is edema.
• Action blocks the effect.
• Acetazolamide blocks the action.
• Acetazolamide is metabolized.

Potassium-Sparing Diuretics

• Spironolactone is a drug.
• Adjuncts with patients who have heart failure.
• Pathophysiology is edema.
• Causes a loss of potassium.
• Spironolactone is metabolized.
• Common adverse effect is related to disturbances in fluid levels such as metabolic acidosis and hyperkalemia.

Osmotic Diuretics

• Mannitol (Osmitrol) is a drug.
• Indicated for increased cranial pressure.
• Contraindicated in acute renal failure due to shock, drug overdose, or trauma.
• Pathophysiology is increased intracranial pressure (ICP) which is a life-threatening condition the results from excess pressure around the brain.
• Pulls water into the renal tubule without sodium loss.
• Not reabsorbed by the tubule, resistant to metabolism.
• Common adverse effects are related to sudden drops in fluid levels which can cause nausea, vomiting, hypotension, light-headedness, confusion, headache, hypovolemia, cardiac decomposition or shock.
• Not as powerful as loop diuretics.

Miscellaneous Drugs

• These treat UTI and BPH.

Antispasmodics

• The drug is oxybutynin.
• Indication is for bladder spasms.
• Pathophysiology in bladder spasms.
• It blocks the sphincters and relaxes them.
• Oxybutynin is metabolized.
• Common adverse effects: dry mouth, headache, fatigue, dizziness, postural dizziness, lethargy

BPH Treatment

• Drugs include doxazosin (Cardura), tamsulosin (Flomax), and finasteride (Proscar).
• Doxazosin and Tamsulosin are alpha blockers.
• Finasteride is a testosterone inhibitor. It is commonly used in combination with an alpha blocker.
• Indicated to treat benign prostatic hypertrophy
• Pathophysiology is benign prostatic hyperplasia, a noncancerous enlargement of the prostate gland, the most common benign tumor found in men.
• Action: alpha blockers relax the sympathetic effects on the bladder; testosterone inhibitors block androgen to shrink the prostate gland.
• The drugs' pharmacokinetics vary with the drug.
• Common adverse events with drug include tachycardia, hypotension, impotence, and sexual dysfunction.
• Consider interactions with other antihypertensives, nitrates, and erectile dysfunction drugs.