How Do Genitourinary Anticholinergics Work?

Genitourinary anticholinergics are medications prescribed to treat bladder overactivity which can cause urinary urgency and incontinence. Genitourinary anticholinergics reduce the symptoms of bladder overactivity by inhibiting bladder contractions.

Genitourinary anticholinergics work by blocking the activity of acetylcholine, a neurotransmitter that nerve endings secrete to make muscles contract. Acetylcholine activates protein molecules known as muscarinic receptors in the inner lining of the bladder, which stimulate the bladder’s detrusor muscle to contract and release urine.

Genitourinary anticholinergics bind to the muscarinic receptors in the bladder lining and prevent acetylcholine from activating muscle contraction. Some of the genitourinary anticholinergics selectively block muscarinic receptors subtype M3, which are directly responsible for the detrusor muscle contraction.

Genitourinary anticholinergics are administered as oral tablets, capsules, or suspensions, approved by the FDA for the treatment of the following conditions:

• Overactive bladder with symptoms of urge, incontinence, urgency, and frequency
• Pediatric neurogenic detrusor overactivity, a condition due to nerve damage or disease that causes overactivity of the bladder wall muscles, which normally relax to hold urine.

Side effects of genitourinary anticholinergics may include the following:

• Dry mouth
• Constipation
• Diarrhea
• Abdominal pain
• Dyspepsia (indigestion)
• Nausea
• Vomiting
• Abdominal distention
• Flatulence
• Gastritis
• Gastroesophageal reflux disease (GERD)
• Ileus (temporary lack of intestinal muscle contraction)
• Dysgeusia (taste disorder)
• Sialadenitis (inflammation of the salivary glands)
• Dysuria (painful urination)
• Urinary retention
• Urinary tract infection (UTI)
• Positive urinalysis bacterial test
• Renal impairment
• Upper respiratory tract infection
• Dry throat
• Cough
• Rhinitis (inflammation of the nasal passage)
• Nasal dryness
• Nasopharyngitis (inflammation of the nose and throat)
• Dysphonia (difficulty with speech)
• Ophthalmological reactions
• Abnormal vision
• Blurred vision
• Xerophthalmia (dry eyes)
• Glaucoma (a condition that damages the optic nerve)
• Vaginitis (inflammation of the vagina)
• Headache
• Dizziness
• Influenza/flu-like syndrome
• Fatigue
• Back pain
• Peripheral edema
• Lower limb edema
• Weight gain
• Insomnia
• Increase in liver enzymes ALT, AST, and GGT
• Chest pain
• Palpitations
• Increase in heart rate
• Tachycardia (rapid heartbeat)
• Supraventricular tachycardia
• Abnormal ECG (QT prolongation)
• Torsades de Pointes (irregular heart rhythm in which the ventricles beat faster and out of synchronization with the atria)
• Hypertension (high blood pressure)
• Syncope (fainting)
• Hypersensitive reactions such as:
  • Rash
  • Dry skin
  • Urticaria (hives)
  • Pruritus (itching)
  • Erythema multiforme (round lesions like a bullseye)
  • Exfoliative dermatitis (skin inflammation with redness and peeling of the skin)
  • Interstitial granuloma annulare (a condition that causes skin lesions in ring patterns)
  • Stevens-Johnson syndrome (a rare medical emergency with flu-like symptoms and a painful rash)
  • Anaphylactic reaction (severe allergic reaction)
  • Angioedema (swelling in the tissue under the skin or mucous membranes)
  • Facial edema
  • Airway obstruction
• Somnolence (drowsiness)
• Hallucinations
• Confusion
• Delirium
• Depression
• Muscular weakness
• Rhabdomyolysis (breakdown of skeletal muscle cells)
• Decreased appetite
• Hyperkalemia (high potassium level in the blood)

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of genitourinary anticholinergic drugs include:

• darifenacin
• Detrol
• Detrol LA
• Enablex
• fesoterodine
• solifenacin
• tolterodine
• Toviaz
• trospium chloride
• VESIcare
• VESIcare LS