oxybutynin (redirected from Cystrin)

oxybutynin /oxy·bu·ty·nin/ (-bu´tĭ-nin) an anticholinergic having direct antispasmodic effect on smooth muscle; used as the chloride salt in the treatment of uninhibited or reflex neurogenic bladder.

---

oxybutynin

an anticholinergic having direct antispasmodic effect on smooth muscle; used in the treatment of uninhibited neurogenic bladder and reflex neurogenic bladder.

---

oxybutynin

Cystrin (UK), Kentera (UK), Oxytrol

Pharmacologic class: Anticholinergic

Therapeutic class: Urinary tract antispasmodic

Pregnancy risk category B

Action

Inhibits acetylcholine action at postganglionic receptors, relaxing smooth muscle lining of GU tract and preventing bladder irritability

Availability

Syrup: 5 mg/5 ml

Tablets: 5 mg

Tablets (extended-release): 5 mg, 10 mg, 15 mg

Transdermal system (patch): 39 cm²/36 mg

⊘Indications and dosages

➣ Frequent urination, urinary urgency or incontinence, and nocturia caused by neurogenic bladder; overactive bladder

Adults: 5 mg P.O. two to three times daily (not to exceed 5 mg q.i.d.); or 5 to 15 mg P.O. once daily (extended-release); or one 3.9 mg/day transdermal system applied twice weekly

Children older than age 5: 5 mg P.O. b.i.d., to a maximum of 5 mg t.i.d.

Dosage adjustment

• Elderly patients

Contraindications

• Hypersensitivity to drug
• Glaucoma
• Intestinal obstruction, severe colitis, atony, paralytic ileus, megacolon, or hemorrhage
• Obstructive uropathy, urinary retention
• Myasthenia gravis
• Acute hemorrhage with shock

Precautions

Use cautiously in:
• cardiovascular disease, hyperthyroidism, GI disease
• elderly patients
• pregnant or breastfeeding patients
• children younger than age 5 (safety not established).

Administration

• Give without regard to food.
• Don't crush or break tablets.

Route	Onset	Peak	Duration
P.O.	30-60 min	3-6 hr	6-10 hr
P.O. (extended)	30-60 min	3-6 hr	Up to 24 hr
Transdermal	24-48 hr	48-96 hr	96 hr after removal

Adverse reactions

CNS: dizziness, drowsiness, hallucinations, insomnia, weakness, anxiety, restlessness, headache

CV: palpitations, hypotension, tachycardia

EENT: blurred vision, cycloplegia, increased intraocular pressure, mydriasis, photophobia

GI: nausea, vomiting, diarrhea, constipation, bloating, dry mouth

GU: urinary hesitancy, urinary retention, erectile dysfunction, suppressed lactation

Metabolic: hyperthermia

Skin: decreased sweating, urticaria

Other: allergic reactions, fever, hot flashes

Interactions

Drug-drug. Anticholinergics, anticholinergic-like drugs (including amantadine, antidepressants, disopyramide, haloperidol, phenothiazines): additive anticholinergic effects

Atenolol: increased atenolol absorption

CNS depressants (including antidepressants, antihistamines, opioids, sedative-hypnotics): additive CNS depression

Digoxin: increased digoxin blood level (with extended-release oxybutynin)

Haloperidol: decreased haloperidol blood level, tardive dyskinesia, worsening of schizophrenia

Levodopa: decreased levodopa efficacy

Nitrofurantoin: increased nitrofurantoin blood level, greater risk of toxicity

Drug-herbs. Angel's trumpet, jimson-weed, scopolia: increased anticholinergic effects

Drug-behaviors. Alcohol use: additive CNS depression

Patient monitoring

• Monitor vital signs and temperature. Watch for hypotension, fever, and tachycardia.
• Evaluate patient's vision.
• Assess results of cystometric studies. Stay alert for urinary retention.

Patient teaching

• Tell patient he may take with or without food. Caution him not to crush, break, or chew extended-release tablets.
• Instruct patient to apply transdermal patch to dry, intact skin on abdomen, hip, or buttock. Tell him to use a new skin area with each new system and not to reapply new patch to same site within 7 days. Caution him not to cut or puncture patch.
• Tell patient to report blurred vision, fever, skin rash, nausea, or vomiting.
• Advise patient he'll need to undergo periodic bladder exams.
• Caution patient to avoid driving and other hazardous activities if drug causes drowsiness or blurred vision.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs, herbs, and behaviors mentioned above.

---

oxybutynin

Ditropan^® Urology A spasmolytic anticholinergic GI and GU tract colic used to ↓ urge incontinence, overactive bladder, bladder Sx associated with neurogenic bladder–eg, frequency, urgency, dysuria, urinary leakage Contraindications Urinary retention, gastric retention, narrow-angle glaucoma Adverse effects Dry mouth, constipation, somnolence, diarrhea, blurred vision, dry eyes, dizziness, rhinitis. See Urge incontinence.