The most common adverse events reported by the 429 patients receiving 5–30 mg/day DITROPAN XL® were the expected side effects of anticholinergic agents. The incidence of dry mouth was dose-related.

The discontinuation rate for all adverse events was 6.8% in the 429 patients from the 4 studies of efficacy and safety who received 5–30 mg/day. The most frequent adverse event causing early discontinuation of study medication was nausea (1.9%), while discontinuation due to dry mouth was 1.2%.

In addition, the following adverse events were reported by ≥ 1 to < 5% of all patients who received DITROPAN XL® in the 6 adjustable and fixed-dose efficacy and safety studies. Infections and infestations: nasopharyngitis, upper respiratory tract infection, sinusitis, bronchitis, cystitis; Psychiatric disorders: insomnia, depression, nervousness, confusional state; Nervous System Disorders: dysgeusia; Cardiac disorders: palpitations; Vascular disorders: hypertension; Respiratory, thoracic and mediastinal disorders: nasal dryness, cough, pharyngolaryngeal pain, dry throat; Gastrointestinal Disorders: gastroesophageal reflux disease, abdominal pain, loose stools, flatulence, vomiting; Skin and subcutaneous tissue disorders: dry skin, pruritis; Musculoskeletal and connective tissue disorders: back pain, arthralgia, pain in extremity; Renal and urinary disorders: urinary retention, urinary hesitation, dysuria; General disorders and administration site conditions: fatigue, edema peripheral, asthenia, chest pain; Investigations: blood pressure increased.

Postmarketing Surveillance
Because postmarketing reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The following additional adverse drug reactions have been reported from worldwide postmarketing experience with DITROPAN XL®: Psychiatric Disorders: psychotic disorder, agitation, hallucinations, memory impairment; Nervous System Disorders: convulsions; Cardiac Disorders: arrhythmia, tachycardia, QT interval prolongation; Vascular Disorders: flushing; Skin and Subcutaneous Tissue Disorders: rash; Renal and Urinary Disorders: impotence; General Disorders and Administration Site Conditions: hypersensitivity reactions, including angioedema with airway obstruction, urticaria, and face edema; rare anaphylactic reactions requiring hospitalization for emergency treatment; Injury, poisoning and procedural complications: fall.

Additional adverse events reported with some other oxybutynin chloride formulations include: cycloplegia, mydriasis, and suppression of lactation.

OVERDOSAGE
The continuous release of oxybutynin from DITROPAN XL® (oxybutynin chloride) should be considered in the treatment of overdosage. Patients should be monitored for at least 24 hours. Treatment should be symptomatic and supportive. Activated charcoal