Oxybutynin


Concise Prescribing Info
Indications/Uses
Overactive bladder.
Dosage/Direction for Use
Adult : PO 2.5-5 mg 2-3 times/day. Max: 5 mg 4 times/day if needed. Extended-release Initial: 5 mg once daily, increase slowly if needed. Max 30 mg/day. Transdermal Per patch delivering 3.9 mg/day: Apply 1 patch to abdomen, hip or buttock twice wkly.
Dosage Details
Oral
Overactive bladder
Adult: 2.5-5 mg bid-tid. May be increased to max 5 mg 4 times daily if necessary. As extended-release preparation: Initially, 5 mg once daily increased by 5 mg every wk if necessary to max 30 mg daily.
Child: >7 yr for nocturnal enuresis: 2.5-3 mg bid increased if necessary to 5 mg bid-tid. Last dose should be given before bedtime. As extended-release preparation: 5 mg once daily, increased by 5 mg wkly if necessary to max 20 mg daily.
Elderly: Initially, 2.5-3 mg bid increased to 5 mg bid if necessary.

Oral
Neurogenic bladder disorders
Child: >5 years As immediate-release tab: 5 mg bid up to tid. As extended-release tab: 5 mg once daily. May increased to Max 15 mg once daily in 5 mg daily increments.

Transdermal
Overactive bladder
Adult: 1 transdermal system (delivering 3.9 mg per day) applied to dry, intact skin on the abdomen, hip, or buttock twice wkly.
Administration
May be taken with or without food.
Contraindications
GI obstruction or atrophy, severe toxic megacolon, significant bladder outflow obstruction, glaucoma, urinary retention.
Special Precautions
Elderly; hepatic or renal impairment; neuropathy; hyperthyroidism; prostatic hyperplasia; hiatus hernia; cardiac disease, reflux oesophagitis, ulcerative colitis, myasthenia gravis; pregnancy and lactation. High environmental temperature might cause heat prostration (fever with heat stroke due to decreased sweating).
Adverse Reactions
Dry mouth, constipation, nausea, abdominal pain; blurred vision; headache, dizziness, drowsiness; dry skin, rash; photosensitivity, diarrhoea, insomnia, palpitation, weakness, dry eyes, confusion, hypertension, UTI, dyspepsia.
PO/Topical/Transdermal: B
Overdosage
Anticholinergic effects including CNS excitation (e.g. restlessness, tremor, irritability, convulsions, delirium, hallucinations), flushing, fever, dehydration, cardiac arrhythmia, vomiting, and urinary retention may occur after overdose. Treatment should be symptomatic and supportive. Activated charcoal may be administered.
Drug Interactions
Co-administration with other anticholinergic drugs may cause undesirable increased anticholinergic effects. Additive sedation with CNS depressants and alcohol. Concentration may be increased by CYP3A4 inhibitirs (e.g. imidazole antifungals, macrolide antibiotics).
Action
Description: Oxybutynin exerts direct antispasmodic effect on the smooth muscle by inhibiting the muscarinic action of acetylcholine. It exhibits moderate anticholinergic effect, but has potent antispasmodic effects on urinary smooth muscle.
Pharmacokinetics:
Absorption: Peak plasma concentrations after 1 hr.
Distribution: Crosses the blood-brain barrier; enters breast milk.
Metabolism: Hepatic: Undergoes first-pass metabolism.
Excretion: Excreted in urine and faeces as metabolites. Elimination half life 2-3 hr.
Storage
Store at 15-30°C (59-86°F).
Disclaimer: This information is independently developed by MIMS based on Oxybutynin from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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