From the Guidelines
Oxybutynin can cause several side effects due to its anticholinergic properties, including dry mouth, constipation, blurred vision, dizziness, and insomnia, with dry mouth and insomnia being more frequently reported compared to tolterodine 1.
Common Side Effects
- Dry mouth
- Constipation
- Blurred vision
- Dizziness
- Insomnia These side effects are commonly associated with antimuscarinics, a class of medications that oxybutynin belongs to, and can lead to discontinuation of treatment due to adverse effects, with oxybutynin having a higher rate of discontinuation compared to placebo 1.
Serious Side Effects
- Confusion
- Hallucinations
- Eye pain
- Irregular heartbeat
- Severe allergic reactions Elderly patients are more susceptible to cognitive side effects like memory problems and confusion, and the extended-release formulation typically causes fewer side effects than immediate-release tablets 1.
Management of Side Effects
If you experience severe or persistent side effects, contact your healthcare provider immediately, as dosage adjustment or medication change may be necessary, and the transdermal patch form may reduce systemic side effects but can cause skin irritation at the application site 1.
Key Considerations
- Oxybutynin blocks acetylcholine receptors throughout the body, not just in the bladder where the therapeutic effect is desired, leading to various side effects 1.
- Discontinuation due to adverse effects was higher with oxybutynin than tolterodine, with a number needed to treat for harm (NNTH) of 14 1.
From the FDA Drug Label
The safety and efficacy of oxybutynin chloride was evaluated in a total of 199 patients in three clinical trials. These participants were treated with oxybutynin chloride 5-20 mg/day for up to 6 weeks. Table 3 shows the incidence of adverse events judged by investigators to be at least possibly related to treatment and reported by at least 5% of patients Table 3 Incidence (%) of Adverse Events Reported by ≥ 5% of Patients Using Oxybutynin Chloride (5-20 mg/day) Body System Adverse Event Oxybutynin Chloride (5-20 mg/day) (n=199) Infections and Infestations Urinary tract infection 6.5% Psychiatric Disorders Insomnia Nervousness 5.5% 6.5% Nervous System Disorders Dizziness Somnolence Headache 16.6% 14.0% 7.5% Eye Disorders Blurred vision 9. 6% Gastrointestinal Disorders Dry mouth Constipation Nausea Dyspepsia 71.4% 15.1% 11.6% 6.0% Renal and Urinary Disorders Urinary Hesitation Urinary Retention 8.5% 6. 0%
The side effects of Oxybutynin (Ditropan) include:
- Common side effects:
- Dry mouth (71.4%)
- Dizziness (16.6%)
- Somnolence (14.0%)
- Urinary tract infection (6.5%)
- Nervousness (6.5%)
- Insomnia (5.5%)
- Blurred vision (9.6%)
- Constipation (15.1%)
- Nausea (11.6%)
- Dyspepsia (6.0%)
- Urinary hesitation (8.5%)
- Urinary retention (6.0%)
- Less common side effects (reported by 1 to <5% of patients):
- Respiratory, Thoracic and Mediastinal Disorders: nasal dryness, cough, pharyngolaryngeal pain, dry throat, sinus congestion, hoarseness, asthma, nasal congestion
- Gastrointestinal Disorders: diarrhea, abdominal pain, loose stools, flatulence, vomiting, abdominal pain upper, dysphagia, aptyalism, eructation, tongue coated
- Skin and Subcutaneous Tissue Disorders: dry skin, pruritis
- Musculoskeletal and Connective Tissue Disorders: back pain, arthralgia, pain in extremity, flank pain
- Renal and Urinary Disorders: dysuria, pollakiuria
- General Disorders and Administration Site Conditions: fatigue, edema peripheral, asthenia, pain, thirst, edema
- Investigations: blood pressure increased, blood glucose increased, blood pressure decreased
- Injury, Poisoning, and Procedural Complications: fall 2
From the Research
Side Effects of Oxybutynin (Ditropan)
- The most common side effects of oxybutynin include dry mouth, which can occur in up to 45% of patients 3
- Other side effects may include application site reactions, such as skin irritation or redness, particularly with the transdermal formulation 4, 5
- Anticholinergic adverse events, such as cognitive impairment and sleep disturbances, may also occur, particularly in elderly patients 6
- The risk of dry mouth and other anticholinergic side effects may be lower with the transdermal formulation of oxybutynin compared to oral formulations 4, 5
- The controlled-release formulation of oxybutynin may have a similar side effect profile to the immediate-release formulation, with dry mouth being the most common adverse event 7
Comparison to Other Medications
- Oxybutynin may have a similar efficacy to other anticholinergic medications, such as tolterodine, but may have a higher risk of dry mouth and other anticholinergic side effects 3
- The transdermal formulation of oxybutynin may have a lower risk of dry mouth and other anticholinergic side effects compared to oral tolterodine 4
- Solifenacin and fesoterodine may have a lower risk of dry mouth and other anticholinergic side effects compared to oxybutynin, but may have a higher risk of other adverse events 3