When would you stop Myrbetriq (mirabegron) in a patient with a history of overactive bladder and recurrent urinary tract infections?

When to Discontinue Mirabegron (Myrbetriq)

Mirabegron should be discontinued immediately if severe uncontrolled hypertension develops (systolic ≥180 mmHg and/or diastolic ≥110 mmHg), if angioedema occurs, or if the patient develops worsening voiding symptoms or urinary retention, particularly in those with bladder outlet obstruction or concurrent antimuscarinic use. 1

Absolute Indications for Discontinuation

Cardiovascular Contraindications

• Stop immediately if severe uncontrolled hypertension develops (systolic BP ≥180 mmHg and/or diastolic BP ≥110 mmHg), as mirabegron is contraindicated in this setting 1
• Discontinue if dose-dependent blood pressure increases occur that cannot be managed with antihypertensive therapy, as mirabegron can cause mean increases of approximately 3.5/1.5 mmHg in systolic/diastolic BP 1
• In the small subset of patients (6.5%) who experience blood pressure elevation despite well-controlled baseline hypertension, stop mirabegron once increased BP is noted rather than adding additional antihypertensive agents 2

Hypersensitivity and Angioedema

• Discontinue immediately if angioedema of the face, lips, tongue, and/or larynx occurs, as this may be life-threatening, particularly with upper airway involvement 1
• Stop if any hypersensitivity reaction to mirabegron or tablet inactive ingredients develops 1

Urinary Retention and Voiding Dysfunction

• Patients should discontinue medication if worsening voiding symptoms or urinary stream is noted after initiation, as recommended by the European Association of Urology for men with lower urinary tract symptoms 3
• Stop if urinary retention develops, particularly in patients with bladder outlet obstruction or those taking concurrent muscarinic antagonist medications 1
• Monitor post-void residual volume regularly and discontinue if clinically significant increases occur 3

Relative Indications for Discontinuation

Recurrent Urinary Tract Infections

• If a patient develops recurrent UTIs (≥3 episodes within 12 months) while on mirabegron, discontinue the medication and evaluate for underlying anatomical abnormalities or complicated UTI risk factors 3
• The most frequent adverse events with mirabegron include UTIs, and if these become recurrent, the medication should be stopped to allow proper evaluation 3, 1
• Consider that recurrent UTIs may indicate underlying bladder dysfunction, high post-void residuals, or other structural abnormalities that warrant imaging and further workup before continuing any OAB therapy 3

Treatment Failure

• Discontinue if inadequate symptom control persists after 4-8 weeks at the 50 mg dose, as this represents the maximum recommended dose and further escalation is not indicated 4
• Consider stopping if no meaningful improvement in OAB symptoms (frequency, urgency, incontinence episodes) is observed by week 4-8, as efficacy should be evident by this timeframe 1

Intolerable Adverse Effects

• Stop if patients develop intolerable headache, nasopharyngitis, or other common adverse effects that significantly impact quality of life 3
• Discontinue if patients experience rare but serious skin reactions or kidney stones 5

Special Population Considerations

Drug Interactions Requiring Discontinuation

• Stop mirabegron if patients require initiation of narrow therapeutic index CYP2D6 substrates (thioridazine, flecainide, propafenone) that cannot be adequately monitored, as mirabegron is a moderate CYP2D6 inhibitor 1
• Consider discontinuation if patients develop cardiac arrhythmias, especially tachycardia, particularly when combined with antimuscarinic drugs due to additive cardiac effects 5

Pregnancy and Lactation

• Discontinue if pregnancy is confirmed or suspected, as there is lack of clinical safety data in pregnant women 5

Surgical Considerations

• Stop mirabegron if patients require cataract surgery and are on concurrent alpha-1 blockers due to increased risk of intraoperative floppy iris syndrome 3

Common Pitfalls to Avoid

• Do not continue mirabegron indefinitely without periodic blood pressure monitoring, especially during initial treatment, as dose-dependent BP increases may develop insidiously 1
• Do not assume UTIs are unrelated to OAB therapy—recurrent infections warrant medication discontinuation and comprehensive urologic evaluation 3
• Do not add additional antihypertensive medications to manage mirabegron-induced hypertension—instead, discontinue mirabegron as the primary intervention 2
• Do not overlook worsening voiding symptoms as a reason to stop therapy, particularly in men with baseline lower urinary tract symptoms or elevated post-void residuals 3