Urinary Pharmacology Drill

Rx Drill

Select a Module

Drugs that decrease urination.

Autonomic control of the bladder.

High-yield tips and mnemonics.

All questions combined.

Progress: 0/0 Accuracy: 100%

Prompt goes here

Drug	Class/Mechanism	Clinical Use	Notes
Desmopressin	Antidiuretic Hormone Analog (V2 Selective)	Central Diabetes Insipidus, Nocturnal Enuresis	Also increases Von Willebrand Factor (useful for bleeding).
Vasopressin	Antidiuretic Hormone Analog (V1 and V2)	Diabetes Insipidus, Septic Shock	V1 causes vasoconstriction; V2 causes water reabsorption.
Thiazides	Paradoxical effect in Nephrogenic Diabetes Insipidus	Nephrogenic Diabetes Insipidus	Causes mild volume depletion, increasing proximal reabsorption of water.
Indomethacin	Nonsteroidal Anti-inflammatory Drug	Nephrogenic Diabetes Insipidus	Prostaglandins normally inhibit Antidiuretic Hormone; blocking them enhances Antidiuretic Hormone effect.

Drug Class	Prototype Drugs	Mechanism of Action	Clinical Use
Antimuscarinics (M3 Antagonists)	Oxybutynin, Tolterodine, Darifenacin, Solifenacin	Block M3 receptors on the detrusor muscle, decreasing bladder contraction.	Urge Incontinence (Overactive Bladder).
Beta-3-Agonists	Mirabegron	Activates Beta-3 receptors in the detrusor, leading to muscle relaxation and increased bladder capacity.	Urge Incontinence; often used if antimuscarinics are poorly tolerated.
Tricyclic Antidepressants	Imipramine	Has strong anticholinergic properties that relax the detrusor.	Historically used for Nocturnal Enuresis (bedwetting) in children.

Drug Class	Prototype Drugs	Mechanism of Action	Clinical Use
Cholinergic Agonists	Bethanechol	Activates M3 receptors on the detrusor muscle to stimulate contraction.	Neurogenic Ileus or Postoperative Urinary Retention.
Alpha-1-Blockers (Selective)	Tamsulosin, Alfuzosin	Block Alpha-1A receptors in the prostate and bladder neck, relaxing smooth muscle to improve flow.	Benign Prostatic Hyperplasia causing overflow issues.
Alpha-1-Blockers (Non-selective)	Terazosin, Doxazosin	Block Alpha-1 receptors in both the prostate and vascular smooth muscle.	Benign Prostatic Hyperplasia in patients who also have Hypertension.
5-Alpha Reductase Inhibitors	Finasteride, Dutasteride	Inhibit the conversion of Testosterone to Dihydrotestosterone, shrinking the prostate over months.	Chronic Benign Prostatic Hyperplasia management to prevent urinary obstruction.

Desmopressin: Does Double Action (V2 selective + Von Willebrand Factor release).
Vasopressin: V1 = Vessels (constriction); V2 = Volume (water reabsorption).
Indomethacin for Diabetes Insipidus: Prostaglandins are "Anti-Antidiuretic Hormone" in the kidney. Indomethacin stops Prostaglandins, so Antidiuretic Hormone works better.
Oxybutynin/Tolterodine: M3 block = "No Pee-Pee." Used for Urge bladder.
Bethanechol: "Beth-any-chol, call the Bladder to empty it all."
Tamsulosin: "Tamsulo-sin" sounds like "Prostate-thin." It relaxes the prostate.
Finasteride: Finasteride = Five-alpha reductase. It takes months to work (shrinking the gland) unlike alpha-blockers which work immediately.
Alpha-1 vs. 5-Alpha Reductase: Alpha-1-blockers fix the Dynamic component (smooth muscle tone). 5-Alpha reductase inhibitors fix the Static component (size of the gland).

Click diagram to zoom