Mirabegron Teva

What Is Mirabegron Teva and What Is It Used For?

Mirabegron Teva is a generic version of mirabegron, manufactured by Teva Pharmaceuticals. Mirabegron belongs to a class of medications known as beta-3 adrenergic receptor agonists, which represent a fundamentally different pharmacological approach to treating overactive bladder compared to the older anticholinergic (antimuscarinic) drugs. The medication was first approved by the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) in 2012 under the brand name Myrbetriq (also marketed as Betmiga in some regions), and generic versions such as Mirabegron Teva have since become available.

Overactive bladder is a common condition characterized by a group of urinary symptoms including urgency (a sudden, compelling desire to urinate that is difficult to defer), urinary frequency (urinating more often than normal, typically eight or more times in 24 hours), and urgency urinary incontinence (involuntary leakage of urine accompanied by or immediately preceded by urgency). OAB affects an estimated 12-17% of the adult population worldwide, with prevalence increasing with age. The condition significantly impacts quality of life, sleep, mental health, and social functioning.

Mirabegron works by selectively activating beta-3 adrenergic receptors located in the detrusor muscle of the urinary bladder. During the storage (filling) phase of the micturition cycle, activation of these receptors causes the detrusor smooth muscle to relax, which increases the functional bladder capacity and reduces the involuntary contractions that cause OAB symptoms. Unlike anticholinergic medications that block muscarinic receptors, mirabegron's mechanism does not interfere with the parasympathetic signaling responsible for bladder contraction during voiding, which contributes to its more favorable side effect profile.

Clinical trials have demonstrated that mirabegron 50 mg once daily significantly reduces the number of incontinence episodes per 24 hours, reduces urinary frequency, and increases the mean volume voided per micturition. The SCORPIO, ARIES, and CAPRICORN phase III trials, involving over 4,000 patients collectively, showed consistent and clinically meaningful improvements in OAB symptoms compared to placebo. In head-to-head studies, mirabegron demonstrated comparable efficacy to anticholinergic agents such as tolterodine and solifenacin.

Mirabegron Teva is available as a 50 mg prolonged-release tablet, which is the standard therapeutic dose for most adult patients. The prolonged-release formulation is designed to provide consistent drug levels throughout the 24-hour dosing interval, supporting once-daily administration and improving patient adherence. In some markets, a lower starting dose of 25 mg may be available, particularly for patients with certain risk factors or organ impairment, though the Mirabegron Teva formulation is specifically available in the 50 mg strength.

What Should You Know Before Taking Mirabegron Teva?

Contraindications

Mirabegron Teva should not be taken in the following situations:

• Hypersensitivity to mirabegron or any of the excipients in the tablet
• Severe uncontrolled hypertension defined as systolic blood pressure of 180 mmHg or higher and/or diastolic blood pressure of 110 mmHg or higher
• End-stage renal disease (GFR <15 mL/min/1.73 m² or patients requiring hemodialysis)
• Severe hepatic impairment (Child-Pugh Class C)

These contraindications are absolute, and mirabegron should not be initiated in patients with any of these conditions. The contraindication regarding severe uncontrolled hypertension is particularly important because mirabegron can cause dose-related increases in blood pressure due to its adrenergic mechanism of action. In clinical trials, mean increases of approximately 0.5-1 mmHg in resting pulse rate and small increases in systolic and diastolic blood pressure were observed.

Warnings and Precautions

Several important warnings and precautions should be considered before and during treatment with Mirabegron Teva:

• Urinary retention: Use with caution in patients with bladder outlet obstruction (BOO) or those taking other medications for urinary symptoms. There is a risk of urinary retention, particularly in patients with significant BOO or those using antimuscarinic agents concurrently
• Urinary tract infection (UTI): UTIs were reported more frequently in patients treated with mirabegron compared to placebo. Patients should be monitored for signs of urinary infection
• Patients with QT prolongation risk: While mirabegron at therapeutic doses did not significantly prolong the QT interval in thorough QT studies, caution is advised in patients with known QT prolongation or those taking medications that prolong the QT interval
• Angioedema: Rare cases of angioedema involving the face, lips, tongue, and/or larynx have been reported post-marketing. If angioedema occurs, mirabegron should be discontinued immediately and appropriate treatment provided
• Moderate renal impairment: No dose adjustment is needed for mild to moderate renal impairment (GFR 15-89 mL/min/1.73 m²), but clinical monitoring is recommended
• Moderate hepatic impairment: In patients with moderate hepatic impairment (Child-Pugh B), the daily dose should not exceed 25 mg (where available). At 50 mg, increased drug exposure has been observed

Pregnancy and Breastfeeding

Mirabegron Teva should not be used during pregnancy unless the potential benefit justifies the potential risk to the fetus. There are no adequate and well-controlled studies of mirabegron use in pregnant women. Animal reproduction studies performed in rats and rabbits showed adverse effects on fetal development at doses that produced systemic exposures significantly higher than the maximum recommended human dose, including decreased fetal weight and delayed ossification.

Women of childbearing potential should use effective contraception during treatment with mirabegron. It is not known whether mirabegron is excreted in human breast milk, although it has been detected in the milk of lactating rats. A decision should be made whether to discontinue breastfeeding or to discontinue therapy, taking into account the importance of the drug to the mother. The EMA product information recommends avoiding mirabegron during breastfeeding.

How Does Mirabegron Teva Interact with Other Drugs?

Mirabegron is metabolized by several cytochrome P450 enzymes (CYP3A4, CYP2D6) and is also a substrate of P-glycoprotein (P-gp) and organic cation transporters. Importantly, mirabegron is a moderate inhibitor of CYP2D6 and a weak inhibitor of CYP3A4. It also inhibits P-glycoprotein at intestinal concentrations. These properties create the potential for clinically significant drug interactions that prescribers must consider.

The CYP2D6 inhibition by mirabegron is particularly relevant because many commonly prescribed medications are metabolized through this enzyme pathway. When mirabegron is co-administered with CYP2D6 substrates that have a narrow therapeutic index, the resulting increase in plasma concentrations of the substrate drug can lead to enhanced pharmacological effects and potential toxicity. For CYP2D6 substrates with a narrow therapeutic index, dose adjustment of the substrate may be necessary.

Major Interactions

Interactions Affecting Mirabegron Levels

When mirabegron is co-administered with strong CYP3A4 inhibitors (such as itraconazole, ketoconazole, or ritonavir), the plasma concentration of mirabegron is increased. In a pharmacokinetic study with ketoconazole 400 mg, mirabegron AUC increased by approximately 1.8-fold. No dose adjustment is generally recommended, but caution is warranted in patients who also have renal or hepatic impairment, as the combined effect may lead to significantly elevated mirabegron levels.

CYP3A4 inducers such as rifampicin can reduce mirabegron plasma concentrations by accelerating its metabolism. Co-administration with rifampicin reduced mirabegron AUC by approximately 45%. If potent enzyme inducers are used concurrently, the therapeutic effect of mirabegron may be diminished, and alternative OAB treatments should be considered.

Mirabegron may also be used in combination with antimuscarinic agents for OAB (such as solifenacin). The SYNERGY and BESIDE trials demonstrated the safety and potential added benefit of combination therapy. However, combination use increases the risk of urinary retention and should be undertaken with appropriate monitoring, especially in patients with bladder outlet obstruction.

What Is the Correct Dosage of Mirabegron Teva?

Adults

In some regions, treatment may be initiated at 25 mg once daily for the first 4-8 weeks, then increased to 50 mg once daily based on individual response and tolerability. However, the Mirabegron Teva 50 mg formulation is prescribed at the full therapeutic dose. Onset of therapeutic effect may be observed within 2 weeks, but full clinical benefit is typically assessed after 8-12 weeks of continuous treatment. Patients should be advised not to discontinue treatment prematurely if they do not notice immediate improvement.

Special Populations

Children and Adolescents

Mirabegron Teva is not recommended for use in children and adolescents under 18 years of age. The safety and efficacy of mirabegron in the pediatric population have not been established in sufficient clinical studies. While some investigational studies have explored mirabegron use in pediatric neurogenic detrusor overactivity, this remains off-label and should only be considered by specialist pediatric urologists in selected cases.

Missed Dose

If you miss a dose of Mirabegron Teva, take it as soon as you remember on the same day. However, if it is almost time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not take two doses at the same time or take extra tablets to make up for the missed dose. If you have difficulty remembering to take your medication, consider setting a daily alarm or using a pill organizer.

Overdose

In clinical studies, single doses of mirabegron up to 400 mg were administered to healthy volunteers. At supratherapeutic doses, the most commonly reported adverse events were increased heart rate and elevated blood pressure. There is no specific antidote for mirabegron overdose. Treatment should be symptomatic and supportive, with monitoring of vital signs, particularly heart rate and blood pressure. In the event of a suspected overdose, contact your local poison control center or seek immediate medical attention. Gastric lavage or administration of activated charcoal may be considered if the overdose has been recent, although the prolonged-release formulation may limit the effectiveness of these measures.

What Are the Side Effects of Mirabegron Teva?

Like all medicines, Mirabegron Teva can cause side effects, although not everybody gets them. The side effect profile of mirabegron has been characterized in large-scale phase III clinical trials (SCORPIO, ARIES, CAPRICORN) involving thousands of patients, as well as through extensive post-marketing surveillance. One of the key advantages of mirabegron over anticholinergic OAB drugs is its significantly lower incidence of dry mouth, which is one of the primary reasons patients discontinue antimuscarinic therapy.

The following frequency classification is used: very common (affects more than 1 in 10 people), common (affects 1 in 10 to 1 in 100 people), uncommon (affects 1 in 100 to 1 in 1,000 people), rare (affects fewer than 1 in 1,000 people), and not known (frequency cannot be estimated from available data).

In long-term studies extending up to 12 months, the safety profile of mirabegron remained consistent with that observed in shorter-term trials. The overall discontinuation rate due to adverse events was comparable between mirabegron 50 mg and placebo groups (approximately 3-5%). Dry mouth, which is the most bothersome side effect of anticholinergic medications and affects up to 30% of patients on some antimuscarinic drugs, occurred at very low rates with mirabegron (approximately 2%, comparable to placebo).

Blood pressure effects deserve particular attention. In pooled analyses of clinical trials, mirabegron 50 mg was associated with mean increases in systolic blood pressure of approximately 0.5-1 mmHg and diastolic blood pressure of approximately 0.5-1 mmHg compared to placebo. While these mean changes are small, individual patients may experience larger increases. Regular blood pressure monitoring is therefore recommended, particularly in patients with pre-existing hypertension. The clinical significance of these small mean blood pressure increases in the overall patient population is considered low, but physicians should exercise judgment in patients with cardiovascular risk factors.

How Should You Store Mirabegron Teva?

Proper storage of medications is essential to ensure their effectiveness and safety. Mirabegron Teva prolonged-release tablets should be stored under the following conditions:

• Temperature: Store below 25°C (77°F). Do not refrigerate or freeze
• Moisture protection: Keep the tablets in the original blister packaging until ready to take. The prolonged-release coating may be sensitive to moisture
• Light: No special light protection requirements, but store in original carton when not in use
• Children: Keep all medicines out of the sight and reach of children
• Expiry date: Do not use Mirabegron Teva after the expiry date stated on the blister and carton. The expiry date refers to the last day of that month

Do not dispose of medications via household waste or wastewater. Ask your pharmacist about proper disposal methods. Many countries offer medication take-back programs through pharmacies. Proper disposal helps protect the environment and prevents accidental ingestion by others.

If you notice any visible changes to the tablets, such as discoloration, crumbling, or an unusual odor, do not take them. Return the medication to your pharmacist for proper disposal and request a replacement from your doctor or pharmacy.

What Does Mirabegron Teva Contain?

Understanding the full composition of your medication is important, particularly if you have known allergies or intolerances to specific excipients. Each Mirabegron Teva 50 mg prolonged-release tablet contains:

Active Substance

Mirabegron 50 mg — Mirabegron is a synthetic beta-3 adrenergic agonist with the chemical name 2-(2-amino-1,3-thiazol-4-yl)-N-[4-(2-{[(2R)-2-hydroxy-2-phenylethyl]amino}ethyl)phenyl]acetamide. The molecular formula is C₂₁H₂₄N₄O₂S, and it has a molecular weight of 396.51 g/mol.

Excipients (Inactive Ingredients)

The tablet core and film coating contain excipients that serve specific formulation functions:

• Tablet core: Polyethylene oxide (release-controlling polymer), povidone (binder), magnesium stearate (lubricant), and other excipients that contribute to the prolonged-release characteristics of the formulation
• Film coating: Hypromellose (film-forming agent), macrogol/polyethylene glycol (plasticizer), iron oxide yellow and/or red (colorants), and titanium dioxide (opacifier). These coating components provide protection for the tablet core and contribute to the tablet's appearance

The prolonged-release technology is a critical feature of Mirabegron Teva. The tablet matrix is designed to release mirabegron gradually over the dosing interval, maintaining therapeutic plasma concentrations throughout 24 hours. This is why the tablets must not be crushed, chewed, or divided, as doing so would compromise the controlled-release mechanism and could lead to rapid release of the full dose, resulting in higher-than-intended peak plasma concentrations and an increased risk of adverse effects.