Oxybutynin Hydrochloride

Indications

Oxybutynin Hydrochloride is used for: Overactive bladder

Adult Dose

Oral Overactive bladder Adult: As extended-release preparation: Initially, 5 mg once daily increased by 5 mg every wk if necessary to max 30 mg daily.

Child Dose

Oral Detrusor Overactivity, Nocturnal enuresis Bladder overactivity associated with a neurologic condition (eg, spina bifida) Child >6 years (extended-release): 5 mg/day PO initially; may be increased by 5 mg/day at weekly intervals; not to exceed 20 mg/day

Renal Dose

Administration

May be taken with or without food.

Contra Indications

GI obstruction or atrophy, severe toxic megacolon, significant bladder outflow obstruction, glaucoma, urinary retention.

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). Lactation: Unknown; use with caution

Pregnancy-Lactation

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).

Side Effects

Side effects of Oxybutynin Hydrochloride : >10% Dry mouth (21-71%), Constipation (7-15%), Somnolence (2-14%), Nausea (2-12%) 1-10% Asthenia (6-10%), Dizziness (6-10%), Headache (6-10%), Blurred vision (6-10%), Dry eyes (6-10%), Diarrhea (6-10%), Nausea (6-10%), Pain (6-10%), Rhinitis (6-10%) <1% Anorexia, Fluid retention, Hot flush, Dysphonia, Dysphagia, Frequent bowel movements, Chest discomfort, Thirst Frequency Not Defined Cycloplegia, Impairment of mental alertness, Memory impairment, Mydriasis, Tachycardia, QT prolongation

Mode of Action

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.