Genitourinary Drugs Flashcards
Urinary system made up of:
Functions
Sex Organs:
Kidneys, ureters, bladder, urethra
- waste and ion disposal i nurine, filters blood, maintains fluid;electrolyte, acid-base balances, produces hormones/enzymes (vitamin D, renin)
- sex organs
Drug Classes:
Diuretics
Urinary tract antispasmodics
Erectile dysfunction therapy drugs
Hormonal contraceptives
Diurectic Drugs promote:
- Thiazide and derivatives:
- Loop:
Potassium-sparing:
Osmotic diuretics:
Carbonic anhydrase inhibitors:
-promote kidney excretion of water, electrolytes
- sulfonamide deriatives; prevent sodium reabsorption by kidneys, water follows excreted sodium; decreased blood volume lowers BP excreted sodium; decreased blood voume lowers BP [chlorothiazide, hydrochlorothiazide (HCTZ)]
- increase sodium, chloride, water secretion; may also inhibit their reabsoption [bumetanide, furosemide]
- increase sodium, water excretion; decrease potassium excretion [spironolactone]
- move fluid into extracellular spaces [mannitol, urea]
-block action of carbonic anhydrase [acetazolamide, methhazolamide]
Diuretic drugs adverse effects
-Thiazide diuretics:
-Loop diuretics:
Potassium-sparing duretics:
- reduced blood volume, orthostatic hypotension, hypoatremia, hypokalemia
- can be severe reaction involving fluid and electrolyte imbalances
-few adverse effects
Osmotic Diuretic are used to treat:
- Acute renal failure
- Cerebral edema
- To reuce intracranial pressure
- to reduce intraocular pressure
- promote urinary excretion of toxic substances
Osmotic Diuretics create:
Increase:
In blood
-create osmotic gradient in glomerular filtrate and blood
- increased osmotic pressure of glomerular filtrate….inhibits reabsorption of sodium, water
- fluid drawn from intracellular to intravascular spaces
Osmotic Diuretics Adverse effects:
- Hyponatremia
- Dehydration
- Circulatory overload (from osmotic effects)
- Thrombophlebitis or local irritation at infusion site
Diuretics:Carbonic Anhydrase inhibitors
Block:
Mainly absorbed:
Distributed in:
Decreases:
- block action of carbonic anhydrase
- Mainly absorbed through GI tract
- Distributed in tissues with high carbonic anhydrase content (erythrocytes, plasma, kidneys, eyes, liver, muscle) -In eyes: reduces aqueous humor production…intraocular pressure reduced.
- decreases hydrogen ions that block sodium-hydrogen exchange mechanisms…excretion of sodium, potassium, bicarbonate, water in urine
Diuretic Carbonic Anhydrase adverse effects:
Hypokalemia
Metabolic acidosis
Electrolyte imbalances
URINARY TRACT ANTISPASMODICS:
Decrease urinary tract muscle spasms by inhibiting parasympathetic activity…..causes detrusor and urinary muscle relaxations [flavoxate, oxybutynin, tolterodine, darifenacin, solifenacinm, trospium]
- Widely distributed metabolized by liver, excreted in urine
- Those that cross placenta….excreted in breast milk
- Used for urinary frequency, urgency, incontinence
Urinary tract antispasmodics:
How the drug Oxybutynin works
Acetycholine:
Oxybutynin:
- released in bladder….attaches to bladder smooth muscle receptors….simulates contractions
- blocks release of acetylcholine….bladder contractions suppressed.
Adverse effects of Antispasmodics/Oxybutynin
- blurred vision
- headaches
- somnolence
- urinary retention
- dry mouth
- duspepsia
- constipation
- nausea
- vomiting
- weight gain
- pain
- acute and secondary angle-closure glaucoma
ERECTILE DYSFUNCTION therapy drugs
For erectile dysfunction due to vascular or neurologic issues
-treats lack of blood flow through corpus cavernosum in penis.
Erectile Dysfunction
Oral absorption in:
Selectively inhibits:
Sildenafil:
- GI tract; metabolized in liver; excreted in feces [sildenafil, tadalafil, vardenafil]
- phosphodiesterase type 5 receptors…increase blood nitric oxide…cGMP enzyme activated….smooth muscle relaxes….blood allowed to flow throug hcorpus cavernosum…erection
- also used for pulmonary arterial hypertension
Erectile Dysfunction
EXCEPTION:
Acts:
- administered directly into corpus cavernosum; metabolized in lungs; excreted in urine [alprostadil]
- locally, promoting smooth muscle relaxation….increases blood flow to corpus cavernosum….erection produced
