Betmiga (Mirabegron): Uses, Dosage & Side Effects

A selective beta-3 adrenoceptor agonist for the treatment of overactive bladder symptoms and neurogenic detrusor overactivity

Rx ATC: G04BD12 Beta-3 Adrenoceptor Agonist
Active Ingredient
Mirabegron
Available Forms
Prolonged-release tablet
Available Strengths
25 mg, 50 mg
Brand Names
Betmiga, Myrbetriq

Betmiga (mirabegron) is a prescription medication used to treat overactive bladder (OAB) in adults, helping to relieve urgency, frequent urination, and urge incontinence. It is also approved for neurogenic detrusor overactivity in children aged 3 to 17 years. As the first selective beta-3 adrenoceptor agonist approved for OAB, Betmiga represents a distinct pharmacological class from traditional anticholinergic bladder medications, offering a different side effect profile with typically less dry mouth and constipation. Approved by the EMA and FDA, it is manufactured by Astellas Pharma.

Quick Facts: Betmiga

Active Ingredient
Mirabegron
Drug Class
Beta-3 Agonist
ATC Code
G04BD12
Common Uses
Overactive Bladder
Available Forms
PR Tablet
Prescription Status
Rx Only

Key Takeaways

  • Betmiga (mirabegron) is a first-in-class beta-3 adrenoceptor agonist that relaxes the bladder muscle to treat overactive bladder symptoms including urgency, frequency, and urge incontinence in adults.
  • Unlike anticholinergic medications (such as oxybutynin or solifenacin), Betmiga works through a different mechanism, resulting in significantly less dry mouth and constipation, making it a preferred option for many patients.
  • The standard adult dose is 50 mg once daily as a prolonged-release tablet, swallowed whole with liquid; it may be taken with or without food. A reduced dose of 25 mg may be used for patients with kidney or liver impairment.
  • Betmiga can raise blood pressure and must not be used in patients with severe uncontrolled hypertension. Blood pressure should be monitored periodically during treatment.
  • Full therapeutic benefit may take 8 to 12 weeks; do not discontinue treatment early if symptoms do not improve immediately, as the bladder needs time to adapt.

What Is Betmiga and What Is It Used For?

Quick Answer: Betmiga (mirabegron) is a prescription medication that relaxes the bladder muscle by activating beta-3 adrenoceptors. It is used to treat overactive bladder (OAB) in adults and neurogenic detrusor overactivity (NDO) in children aged 3–17 years, reducing symptoms such as urgency, frequency, and urinary incontinence.

Betmiga contains the active substance mirabegron, a selective beta-3 adrenoceptor agonist. It belongs to a pharmacological class that is fundamentally different from the anticholinergic drugs that have traditionally been used to treat overactive bladder. By selectively activating beta-3 adrenergic receptors located on the detrusor smooth muscle of the urinary bladder, mirabegron promotes relaxation of the bladder wall during the filling (storage) phase of the micturition cycle. This increases the functional capacity of the bladder and reduces the involuntary contractions that cause the characteristic symptoms of overactive bladder.

Overactive bladder (OAB) is a common condition that affects an estimated 12–17% of the adult population worldwide, with prevalence increasing with age. The syndrome is characterized by urinary urgency (a sudden, compelling desire to urinate that is difficult to defer), usually accompanied by increased daytime urinary frequency (more than 8 voids per day) and nocturia (waking to urinate during the night), with or without urgency urinary incontinence (involuntary leakage of urine associated with urgency). OAB significantly impacts quality of life, affecting sleep, work productivity, social activities, and psychological wellbeing, with many patients also experiencing anxiety and depression related to their symptoms.

Betmiga is approved by the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA, marketed as Myrbetriq in the United States) for the symptomatic treatment of urgency, increased micturition frequency, and urgency incontinence in adults with overactive bladder. It was the first beta-3 agonist to receive regulatory approval for this indication, representing a significant advancement in the pharmacotherapy of OAB by offering a mechanism of action distinct from anticholinergics.

In addition to its use in adult OAB, Betmiga is approved for the treatment of neurogenic detrusor overactivity (NDO) in children and adolescents aged 3 to under 18 years. NDO is a condition characterized by involuntary contractions of the bladder detrusor muscle caused by a neurological condition (such as spina bifida or spinal cord injury) or damage to the nerves controlling bladder function. If left untreated, NDO can lead to progressive damage to the bladder and kidneys. In pediatric NDO, Betmiga is used to increase bladder capacity and reduce urinary leakage, helping to protect the upper urinary tract and improve quality of life.

The clinical efficacy of mirabegron has been demonstrated in several large-scale, randomized, double-blind, placebo-controlled phase III trials involving over 10,000 patients with OAB. In the pivotal SCORPIO, ARIES, and CAPRICORN studies, mirabegron 50 mg significantly reduced the mean number of incontinence episodes per 24 hours and the mean number of micturitions per 24 hours compared with placebo. The BEYOND study demonstrated the long-term safety and sustained efficacy of mirabegron over 12 months of treatment. For pediatric NDO, the RAINBOW study established safety and efficacy in children aged 3–17 years.

What Should You Know Before Taking Betmiga?

Quick Answer: Do not take Betmiga if you are allergic to mirabegron or have severe uncontrolled high blood pressure. Use caution if you have kidney or liver problems, urinary retention, QT prolongation, or are taking certain other medications. Betmiga should not be used during pregnancy or breastfeeding.

Contraindications

There are specific medical situations in which Betmiga must not be used. Understanding these contraindications is critical for safe treatment. You should not take Betmiga if:

  • Allergy: You are allergic to mirabegron or any of the other ingredients in the tablet (including macrogol, hydroxypropylcellulose, butylhydroxytoluene, magnesium stearate, hypromellose, iron oxide yellow E172, or iron oxide red E172).
  • Severe uncontrolled hypertension: You have very high blood pressure that is not adequately controlled with treatment. Betmiga can further increase blood pressure and must not be used in this situation.

Warnings and Precautions

Blood Pressure Monitoring

Betmiga can cause increases in blood pressure. Your doctor should measure your blood pressure before starting treatment and at regular intervals during therapy, particularly if you have a history of hypertension. Report any symptoms of severely elevated blood pressure, such as sudden severe headache (especially throbbing, migraine-like headache), to your doctor immediately.

Talk to your doctor or pharmacist before taking Betmiga if any of the following apply to you:

  • Urinary retention or bladder outlet obstruction: If you have difficulty emptying your bladder completely, have a weak urinary stream, or are taking other medications for overactive bladder (such as anticholinergic drugs), you may be at increased risk of urinary retention (inability to empty the bladder). Betmiga may increase this risk. Tell your doctor immediately if you cannot urinate after starting this medication.
  • Kidney or liver problems: Your doctor may need to reduce your dose of Betmiga or advise against its use, particularly if you are also taking medications such as itraconazole, ketoconazole (antifungals), ritonavir (HIV/AIDS treatment), or clarithromycin (antibiotic). Inform your doctor of all medications you are taking.
  • QT prolongation on ECG: If you have been told you have an abnormality on your electrocardiogram (ECG) called QT prolongation, or if you are taking any medication known to cause this, including certain drugs for irregular heart rhythm (quinidine, sotalol, procainamide, ibutilide, flecainide, dofetilide, amiodarone), certain antihistamines for allergic rhinitis, certain antipsychotic medications (thioridazine, mesoridazine, haloperidol, chlorpromazine), and certain anti-infective agents (pentamidine, moxifloxacin, erythromycin, clarithromycin).
Children and Adolescents

Betmiga should not be given to children and adolescents under 18 years of age for the treatment of overactive bladder, as its safety and efficacy have not been established in this age group for OAB. However, Betmiga is approved for the treatment of neurogenic detrusor overactivity in children aged 3 to under 18 years, with dosing based on body weight as determined by the prescribing physician. Betmiga should not be used for NDO in children under 3 years of age.

Pregnancy and Breastfeeding

Betmiga should not be taken during pregnancy. If you are pregnant, think you may be pregnant, or are planning to become pregnant, do not take Betmiga. There is insufficient data on the use of mirabegron in pregnant women, and animal studies have shown effects on reproductive parameters. As a precaution, this medication should be avoided during pregnancy.

If you are breastfeeding, consult your doctor or pharmacist before using Betmiga. Mirabegron is likely to pass into breast milk based on animal data. You and your doctor should decide whether to take Betmiga or to breastfeed; it is recommended not to do both simultaneously. If the medication is essential, alternatives to breastfeeding should be considered during the period of treatment.

Driving and Operating Machinery

There is no evidence that Betmiga at recommended doses affects your ability to drive or operate machinery. Mirabegron does not cause drowsiness or impair cognitive function at therapeutic doses. However, if you experience dizziness (an uncommon side effect), exercise caution when driving or using machinery until you know how the medication affects you.

How Does Betmiga Interact with Other Drugs?

Quick Answer: Betmiga can interact with several medications, including digoxin, dabigatran, thioridazine, flecainide, propafenone, imipramine, desipramine, and strong CYP3A4 inhibitors such as itraconazole and ketoconazole. Always inform your doctor about all medications, supplements, and herbal remedies you are taking.

Mirabegron is metabolized by several enzyme systems and is itself an inhibitor of CYP2D6 and a moderate inhibitor of P-glycoprotein (P-gp). This means it can affect the blood levels and efficacy of other medications, and certain drugs can also alter mirabegron levels in your body. Understanding these interactions is essential for safe and effective treatment.

Major Interactions

Major Drug Interactions with Betmiga (Mirabegron)
Interacting Drug Effect Clinical Advice
Digoxin Mirabegron inhibits P-glycoprotein and may increase digoxin blood levels, potentially leading to digitalis toxicity Your doctor should monitor digoxin blood levels when starting or stopping Betmiga. Dose adjustment of digoxin may be necessary.
Dabigatran etexilate Mirabegron may increase dabigatran levels via P-glycoprotein inhibition, potentially increasing bleeding risk Use with caution. Your doctor may need to adjust the dose of dabigatran. Report any unusual bleeding or bruising immediately.
Thioridazine Mirabegron inhibits CYP2D6, which metabolizes thioridazine. Increased thioridazine levels may prolong the QT interval and increase the risk of serious cardiac arrhythmias The combination should generally be avoided. If concurrent use is necessary, your doctor may reduce the thioridazine dose and monitor cardiac function.
Flecainide and Propafenone These antiarrhythmic drugs are metabolized by CYP2D6. Mirabegron may increase their plasma concentrations, potentially causing proarrhythmic effects Your doctor may need to adjust doses of flecainide or propafenone. Regular cardiac monitoring is recommended.
Itraconazole, Ketoconazole, Ritonavir Strong CYP3A4 inhibitors can increase mirabegron blood levels, potentially intensifying side effects Your doctor may reduce the Betmiga dose (e.g., to 25 mg) or advise against use, particularly in patients with existing kidney or liver impairment.

Minor Interactions

Minor Drug Interactions with Betmiga (Mirabegron)
Interacting Drug Effect Clinical Advice
Imipramine and Desipramine These tricyclic antidepressants are metabolized by CYP2D6. Mirabegron may modestly increase their blood levels Your doctor may adjust the dose of the antidepressant. Monitor for increased sedation or anticholinergic effects.
Clarithromycin A moderate CYP3A4 inhibitor that may increase mirabegron exposure Generally no dose adjustment needed at standard doses, but be aware of potential for increased Betmiga effects. Inform your doctor.
Anticholinergic bladder drugs (solifenacin, oxybutynin) Combination may provide additional OAB symptom relief but may also increase the risk of urinary retention and other side effects Combination therapy should only be used under medical supervision. Report any difficulty urinating to your doctor immediately.
Metformin Mirabegron may increase metformin exposure via OCT1/OCT2 transporter inhibition No routine dose adjustment is needed, but monitor blood glucose more closely when starting or stopping Betmiga.
Important Note on Drug Interactions

Always inform your doctor, pharmacist, or nurse about all medications you are taking, have recently taken, or might take, including over-the-counter medicines and herbal supplements. Mirabegron is a CYP2D6 inhibitor, which means it can potentially affect the metabolism of many drugs. This is particularly important for medications with a narrow therapeutic index, where small changes in blood levels can have significant clinical consequences.

What Is the Correct Dosage of Betmiga?

Quick Answer: The recommended adult dose is one 50 mg prolonged-release tablet taken once daily by mouth. For patients with moderate kidney or liver impairment, the dose may be reduced to 25 mg once daily. The tablet must be swallowed whole and not crushed or chewed. For children with NDO, the dose is determined by body weight.

Always take Betmiga exactly as your doctor has prescribed. Do not change your dose without consulting your doctor. The following dosing information provides general guidance; your prescriber may adjust these recommendations based on your individual medical circumstances, kidney and liver function, and other medications you are taking.

Adults with Overactive Bladder

Standard Adult Dosing

Recommended dose: One 50 mg prolonged-release tablet, taken once daily by mouth

Administration: Swallow the tablet whole with liquid. Do not crush, divide, or chew the tablet, as this will alter the prolonged-release mechanism and may lead to improper drug release

Food: Betmiga may be taken with or without food

Reduced dose (25 mg): May be prescribed for patients with moderate renal impairment (eGFR 15–29 ml/min/1.73 m²) or moderate hepatic impairment (Child-Pugh class B), or when taken with potent CYP3A4 inhibitors in patients with impaired renal or hepatic function

In patients with severe renal impairment (eGFR below 15 ml/min/1.73 m², including end-stage renal disease) or severe hepatic impairment (Child-Pugh class C), Betmiga is not recommended because it has not been adequately studied in these populations. For patients with mild renal or hepatic impairment, no dose adjustment is generally required.

Children and Adolescents (3 to Under 18 Years) with Neurogenic Detrusor Overactivity

Pediatric Dosing (NDO Only)

Administration: One prolonged-release tablet, taken once daily by mouth with food

Dosing: The dose is calculated by the doctor based on the patient's body weight. The prescriber will determine whether a 25 mg or 50 mg tablet is appropriate

Important: The tablet must be swallowed whole with liquid and must not be crushed or chewed

Note: Betmiga is not approved for overactive bladder in children. It should only be used in pediatric patients for neurogenic detrusor overactivity as prescribed by a specialist physician

Elderly Patients

No dose adjustment is specifically required for elderly patients based on age alone. However, since the prevalence of renal and hepatic impairment increases with age, elderly patients should have their kidney and liver function assessed before starting Betmiga. In clinical trials, the safety and efficacy profile of mirabegron was consistent across age groups, including patients over 65 years and over 75 years. As with all medications, elderly patients should be monitored for side effects, particularly blood pressure changes, and dose reduction should be considered if kidney or liver function is significantly reduced.

Missed Dose

If you forget to take your Betmiga tablet, take the missed dose as soon as you remember. However, if it is less than 12 hours until your next scheduled dose, skip the missed dose and take your next tablet at the usual time. Do not take a double dose to make up for a forgotten dose. If you miss several doses in a row, contact your doctor for advice on how to proceed.

Overdose

Symptoms of mirabegron overdose may include strong, forceful heartbeat (palpitations), increased heart rate (tachycardia), and elevated blood pressure. In clinical studies, single doses of mirabegron up to 400 mg were administered to healthy volunteers and caused increased heart rate and blood pressure. There is no specific antidote for mirabegron overdose; treatment is supportive and symptomatic, including monitoring of heart rate and blood pressure. If overdose is suspected, medical attention should be sought promptly.

Stopping Treatment

Do not stop taking Betmiga without first consulting your doctor. Even if you do not see an immediate improvement, the bladder may need time to adapt to the medication, and full therapeutic benefit may take 8 to 12 weeks. If you stop treatment prematurely, your symptoms of overactive bladder or neurogenic detrusor overactivity are likely to return. If you and your doctor decide to discontinue Betmiga, no gradual dose tapering is generally required; the medication can be stopped abruptly. However, always follow your doctor's specific instructions regarding treatment changes.

What Are the Side Effects of Betmiga?

Quick Answer: Common side effects include urinary tract infection, headache, dizziness, rapid heartbeat, nausea, constipation, and diarrhea. The most serious potential side effect is atrial fibrillation (irregular heart rhythm). Betmiga may also raise blood pressure. Seek immediate medical attention if you experience irregular heartbeat, sudden severe headache, or signs of an allergic reaction.

Like all medicines, Betmiga can cause side effects, although not everybody gets them. The following section classifies the known side effects by frequency, based on data from clinical trials and post-marketing surveillance. Most side effects are mild to moderate and do not require discontinuation of treatment.

Common

May affect up to 1 in 10 people
  • Urinary tract infection: Symptoms may include burning or pain when urinating, increased frequency, or cloudy urine
  • Headache: Usually mild and transient
  • Dizziness: May occur particularly when standing up quickly
  • Tachycardia: Rapid heartbeat (increased heart rate)
  • Nausea: Feeling sick to the stomach
  • Constipation: Difficulty passing stools
  • Diarrhea: Loose or frequent bowel movements

Uncommon

May affect up to 1 in 100 people
  • Vaginal infection: Symptoms include itching, unusual discharge, or discomfort
  • Cystitis: Bladder inflammation causing pain and urgency
  • Palpitations: Awareness of heartbeat, sometimes described as pounding or fluttering
  • Atrial fibrillation: Irregular heart rhythm – a potentially serious side effect
  • Dyspepsia: Indigestion or stomach discomfort
  • Gastritis: Inflammation of the stomach lining
  • Skin reactions: Itching (pruritus), rash, hives (urticaria), macular rash, papular rash
  • Joint swelling: Pain or swelling in the joints
  • Vulvovaginal pruritus: Itching of the vulva or vagina
  • Elevated blood pressure: May occur without symptoms
  • Raised liver enzymes: Increases in GGT, AST, and ALT detected on blood tests

Rare

May affect up to 1 in 1,000 people
  • Eyelid edema: Swelling of the eyelids
  • Lip edema: Swelling of the lips
  • Leukocytoclastic vasculitis: Inflammation of small blood vessels, primarily affecting the skin
  • Purpura: Small purple spots on the skin caused by bleeding under the skin
  • Angioedema: Swelling of deeper skin layers, which may affect the face, tongue, or throat and can cause breathing difficulties – seek emergency help immediately
  • Urinary retention: Inability to fully empty the bladder

Very Rare

May affect up to 1 in 10,000 people
  • Hypertensive crisis: Extremely high blood pressure that may cause severe headache, visual changes, chest pain, or confusion – this is a medical emergency

Frequency Not Known

Cannot be estimated from available data
  • Insomnia: Difficulty falling or staying asleep
  • Confusion: Difficulty thinking clearly or disorientation
Urinary Retention Risk

Betmiga may increase the likelihood of being unable to empty your bladder if you have an obstruction in the lower urinary tract (such as an enlarged prostate) or if you are taking other medications to treat overactive bladder (anticholinergics). Talk to your doctor immediately if you experience difficulty urinating or are unable to pass urine after starting this medication.

If you experience any side effects, including any not listed above, report them to your doctor, pharmacist, or nurse. You can also report suspected side effects directly to your national pharmacovigilance authority (for example, the MHRA Yellow Card scheme in the UK, the FDA MedWatch program in the US, or the EMA EudraVigilance system in the EU). Reporting side effects helps regulators continue to monitor the benefit-risk balance of this medication.

How Should You Store Betmiga?

Quick Answer: Store Betmiga at room temperature in its original packaging. Keep out of the reach and sight of children. Do not use after the expiry date on the carton or blister pack. Dispose of unused medication through your pharmacy, not in household waste or drains.

Proper storage of Betmiga helps ensure that the medication remains effective and safe throughout its shelf life. The following storage guidelines should be followed:

  • Temperature: No special storage conditions are required. Store at room temperature, away from excessive heat or moisture.
  • Packaging: Keep the tablets in their original aluminium-aluminium blister packs until you are ready to take a dose. This protects them from moisture and light.
  • Child safety: Keep this medicine out of the sight and reach of children. Accidental ingestion by a child could cause serious adverse effects including rapid heartbeat and elevated blood pressure.
  • Expiry date: Do not use Betmiga after the expiry date stated on the carton or blister pack after “EXP.” The expiry date refers to the last day of the stated month.
  • Disposal: Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer need. These measures help to protect the environment.

Betmiga is available in blister packs containing 10, 20, 30, 50, 60, 90, 100, or 200 tablets. Not all pack sizes may be marketed in your country. Your pharmacist will dispense the appropriate pack size based on your prescription.

What Does Betmiga Contain?

Quick Answer: The active ingredient is mirabegron (25 mg or 50 mg per tablet). Inactive ingredients include macrogol, hydroxypropylcellulose, butylhydroxytoluene, magnesium stearate, and a film coating containing hypromellose, macrogol, and iron oxide coloring agents. The 25 mg tablets are brown and oval; the 50 mg tablets are yellow and oval.

Understanding the full composition of Betmiga is important, particularly if you have known allergies to any pharmaceutical excipients. The active and inactive ingredients differ slightly between the two available strengths.

Active Ingredient

Betmiga 25 mg prolonged-release tablets: Each tablet contains 25 mg of mirabegron.

Betmiga 50 mg prolonged-release tablets: Each tablet contains 50 mg of mirabegron.

Inactive Ingredients (Excipients)

Tablet core: Macrogol (polyethylene glycol), hydroxypropylcellulose, butylhydroxytoluene (BHT, an antioxidant), and magnesium stearate.

Film coating: Hypromellose (hydroxypropyl methylcellulose), macrogol, iron oxide yellow (E172). The 25 mg tablet additionally contains iron oxide red (E172), which gives it its characteristic brown color.

Tablet Appearance

Betmiga 25 mg: Oval, brown film-coated prolonged-release tablets, embossed with the company logo and “325” on the same side.

Betmiga 50 mg: Oval, yellow film-coated prolonged-release tablets, embossed with the company logo and “355” on the same side.

If you have a known allergy to any excipient, particularly butylhydroxytoluene (BHT) or iron oxide colorants, inform your doctor or pharmacist before starting Betmiga. Betmiga is manufactured by Delpharm Meppel B.V. (Netherlands) and marketed by Astellas Pharma Europe B.V. The medication is also available in the United States under the brand name Myrbetriq (Astellas Pharma US, Inc.).

Frequently Asked Questions About Betmiga

Betmiga (mirabegron) is prescribed to treat overactive bladder (OAB) in adults. OAB is a condition characterized by a sudden, strong urge to urinate (urgency), needing to urinate more often than normal (increased frequency), and involuntary leakage of urine associated with urgency (urge incontinence). Betmiga works by relaxing the bladder muscle during filling, allowing the bladder to hold more urine and reducing these bothersome symptoms. It is also approved for treating neurogenic detrusor overactivity in children aged 3 to under 18 years, where involuntary bladder contractions occur due to a neurological condition or nerve damage.

Betmiga belongs to a completely different drug class than traditional anticholinergic (antimuscarinic) medications such as oxybutynin, tolterodine, solifenacin, darifenacin, or fesoterodine. While anticholinergics work by blocking muscarinic acetylcholine receptors to reduce bladder muscle contractions, Betmiga activates beta-3 adrenergic receptors to relax the bladder muscle. This fundamental difference in mechanism means that Betmiga generally causes significantly less dry mouth (xerostomia) and constipation, which are among the most common reasons patients discontinue anticholinergic therapy. Betmiga also does not cross the blood-brain barrier to a significant extent, making it less likely to cause cognitive side effects that have been associated with some anticholinergic medications, particularly in elderly patients.

The recommended dose for adults with overactive bladder is one 50 mg prolonged-release tablet taken once daily. The tablet should be swallowed whole with liquid and must not be crushed, divided, or chewed. It can be taken with or without food, at any time of day, though many patients find it convenient to take it at the same time each day. A lower dose of 25 mg once daily may be prescribed if you have moderate kidney or liver impairment, or if you are taking certain medications (strong CYP3A4 inhibitors) that may increase mirabegron blood levels. For children with neurogenic detrusor overactivity, the dose is individually determined by the physician based on the child's body weight.

Yes, Betmiga can cause a small increase in blood pressure in some patients. In clinical trials, mean increases of approximately 1 mmHg in systolic blood pressure and 0.5 mmHg in diastolic blood pressure were observed compared to placebo. While these average increases are modest, individual patients may experience more significant elevations. For this reason, your doctor should check your blood pressure before starting treatment and periodically during therapy. Betmiga is strictly contraindicated in patients with severe uncontrolled hypertension (systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥110 mmHg). In very rare cases, hypertensive crisis (extremely high blood pressure) has been reported. Seek immediate medical attention if you develop sudden severe headache, particularly if it is throbbing or migraine-like.

Some patients may notice improvement in their overactive bladder symptoms within the first 2 to 4 weeks of starting Betmiga. However, the full therapeutic benefit is typically seen after 8 to 12 weeks of continuous treatment. It is very important not to discontinue Betmiga early if you do not see immediate results. The bladder undergoes physiological adaptation during treatment, and stopping the medication too soon may prevent you from experiencing its full benefit. In clinical trials, statistically significant improvements in incontinence episodes and urinary frequency were demonstrated at 12 weeks. If after 12 weeks of treatment you have not experienced adequate symptom improvement, discuss alternative treatment options with your doctor.

Yes, Betmiga can be used in combination with certain anticholinergic medications under medical supervision. The combination of mirabegron 50 mg with solifenacin 5 mg (marketed in some countries as the fixed-dose combination Betmiga Plus) has been studied in the BESIDE and SYNERGY clinical trials and shown to provide additional symptom relief in patients who do not respond adequately to either drug alone. However, combining Betmiga with anticholinergics may increase the risk of urinary retention and requires careful medical oversight. You should never combine medications for overactive bladder without your doctor's explicit recommendation and monitoring.

References

This article is based on current international medical guidelines, regulatory documents, and peer-reviewed research. All sources meet evidence level 1A standards.

  1. European Medicines Agency (EMA). Betmiga (Mirabegron) – Summary of Product Characteristics. EMA/CHMP; 2024. Comprehensive regulatory document covering indications, dosing, contraindications, and safety data for the European market.
  2. U.S. Food and Drug Administration (FDA). Myrbetriq (Mirabegron) Extended-Release Tablets – Prescribing Information. Astellas Pharma US, Inc.; 2024. Complete FDA-approved labeling including indications, dosage, warnings, and clinical pharmacology.
  3. Khullar V, Amarenco G, Angulo JC, et al. Efficacy and tolerability of mirabegron, a beta-3 adrenoceptor agonist, in patients with overactive bladder: Results from a randomised European-Australian phase 3 trial (SCORPIO). European Urology. 2013;63(2):283-295. doi:10.1016/j.eururo.2012.10.016
  4. Nitti VW, Auerbach S, Martin N, Calhoun A, Lee M, Herschorn S. Results of a randomized phase III trial of mirabegron in patients with overactive bladder (ARIES). Journal of Urology. 2013;189(4):1388-1395. doi:10.1016/j.juro.2012.10.017
  5. European Association of Urology (EAU). EAU Guidelines on Management of Non-Neurogenic Female Lower Urinary Tract Symptoms. EAU; 2024. Recommends mirabegron as a first-line pharmacological option for overactive bladder.
  6. Herschorn S, Barkin J, Castro-Diaz D, et al. A phase III, randomized, double-blind, parallel-group, placebo-controlled, multicentre study to assess the efficacy and safety of the beta-3 adrenoceptor agonist, mirabegron, in patients with symptoms of overactive bladder (CAPRICORN). Urology. 2013;82(2):313-320. doi:10.1016/j.urology.2013.02.077
  7. Chapple CR, Kaplan SA, Mitcheson D, et al. Randomized double-blind, active-controlled phase 3 study to assess 12-month safety and efficacy of mirabegron, a beta-3 adrenoceptor agonist, in overactive bladder (BEYOND). European Urology. 2013;63(2):296-305. doi:10.1016/j.eururo.2012.10.048
  8. National Institute for Health and Care Excellence (NICE). Urinary incontinence and pelvic organ prolapse in women: management (NG123). NICE; 2019 (updated 2024). Recommends mirabegron as an alternative to antimuscarinics for OAB.
  9. Abrams P, Kelleher C, Staskin D, et al. Combination treatment with mirabegron and solifenacin in patients with overactive bladder: efficacy and safety results from a randomised, double-blind, dose-ranging, phase 2 study (SYMPHONY). European Urology. 2015;67(3):577-588. doi:10.1016/j.eururo.2014.02.012
  10. International Continence Society (ICS). ICS Standards 2024: Terminology and Definitions for Overactive Bladder. ICS; 2024. Standardized definitions of OAB symptoms and diagnostic criteria.

Editorial Team

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