Chapter 15

Chapter 15Urinary System DrugsCopyright 2015 Cengage LearningIntroductionThe following slides discuss various urinary system drugsRefer to the chapter for specific uses, side effects, contraindications, and interactions

2Copyright 2015 Cengage Learning2DiureticsMost commonly used drugs influencing function of the urinary tractMain indication is to reduce circulating fluid volume to help treat edema and hypertensionFive categoriesThiazides, loop diuretics, potassium-sparing diuretics, osmotic agents, and carbonic anhydrase inhibitors3Copyright 2015 Cengage Learning3Diuretics (contd.)ThiazidesMost frequently used diureticIncrease excretion of water, sodium, chloride, and potassiumLoop diureticsAct directly on the loop of Henle in the kidney Inhibit sodium and chloride reabsorption; inhibits water reabsorption back into the bloodstream; leads to increased urine formation4Copyright 2015 Cengage Learning4Diuretics (contd.)Potassium-sparing diuretics Sometimes administered under conditions in which potassium depletion can be dangerousMay counteract increased glucose and uric acid levels associated with thiazide diuretic therapySeldom used alone

5Copyright 2015 Cengage Learning5Diuretics (contd.)Osmotic agents (e.g., mannitol) Most frequently used to reduce intracranial or intraocular pressure6Copyright 2015 Cengage Learning6Medications for GoutWhat is gout?A form of arthritis and a metabolic disorderCharacterized by accumulation of uric acid crystals in various joints, tissues, and sometimes the kidneys, with resultant inflammation and painManagement includes treating acute attacks, uric acid-lowering therapy, and preventing recurrence of acute attacksOnset of acute gout is characterized by sudden onset of pain, redness, warmth, and swelling in the affected joints7Copyright 2015 Cengage Learning78

Copyright 2015 Cengage LearningFigure 15-1 8Medications for Gout (contd.)Non-steroidal anti-inflammatory drugs (NSAIDs) and colchicineNSAIDs work quickly to relieve pain when started soon after symptom onsetColchicine is used to relieve inflammation in acute gouty arthritis and in chronic management of gout9Copyright 2015 Cengage Learning9Medications for Gout (contd.)Uricosuric agentsAct on the kidney by blocking reabsorption and thereby promoting urinary excretion of uric acidUsed in treatment of chronic cases of gout and frequent disabling attacks of gouty arthritisNo analgesic or anti-inflammatory activity and not effective in treatment of acute gout10Copyright 2015 Cengage Learning10Medications for Gout (contd.)Xanthine oxidase inhibitors allopurinolUsed to treat chronic goutResults in decreased serum and urinary levels of uric acidNo analgesic or anti-inflammatory activity and not effective in treatment of acute gout11Copyright 2015 Cengage Learning11Bladder AntispasmodicsWhat is overactive bladder (OAB)?Condition characterized by two urinary symptoms: frequency and urgencyAntispasmodics are used to increase capacity, decrease urgency of the urinary bladder, decrease bladder tone, and suppress bladder contractions in patients with neurogenic bladder resulting in decreased incontinence12Copyright 2015 Cengage Learning12CholinergicsBethanechol (Urecholine) is a cholinergic drugStimulates parasympathetic nerves to bring about contraction of the urinary bladder in cases of nonobstructive urinary retentionUsually used postoperatively or postpartumPharmacological catheterization13Copyright 2015 Cengage Learning13Urinary AnalgesicsPhenazopyridine (Pyridium) is an oral urinary analgesic or local anesthetic for urinary tract mucosaUsed short-term to relieve burning, pain, discomfort, and urgency associated with cystitis (bladder inflammation)Used only for symptomatic relief 14Copyright 2015 Cengage Learning14Treatment of Benign Prostatic Hyperplasia Benign prostatic hyperplasia (BPH) is the most common benign tumor in menInvolves hyperplasia leading to prostate enlargement that interferes with urination flowDrugs used to treat symptoms slow prostate growth and relax the bladder smooth muscle to make it easier for urine to flow from the bladder through the urethra15Copyright 2015 Cengage Learning15Treatment of Benign Prostatic Hyperplasia (contd.) AntiandrogensFinasteride and dutasteride work by suppressing prostate growthUsed to reduce prostate size and associated urinary obstruction and manifestationsAppears to be suppressive rather than curative, and return of the hypertrophy is likely if the drug is withdrawn16Copyright 2015 Cengage Learning16Treatment of Benign Prostatic Hyperplasia (contd.) Alpha-blockers Tamsulosin (Flomax) blocks alpha-1 receptors found in smooth muscle in the bladder neck and prostate, causing them to relaxUrine flow rate is improved and the symptoms of BPH are decreasedFirst-line therapy for the treatment of BPH17Copyright 2015 Cengage Learning17Treatment of Benign Prostatic Hyperplasia (contd.) Phosphodiesterase (PDE) inhibitorTadalafil (Cialis) is a PDE inhibitor approved for the treatment of erectile dysfunctionRecently approved to treat the signs and symptoms of BPH18Copyright 2015 Cengage Learning18