Megatas Plus
Megatas Plus Uses, Dosage, Side Effects, Food Interaction and all others data.
Mirabegron is a potent and selective beta 3-adrenoceptor agonist. Mirabegron showed relaxation of bladder smooth muscle in rat and human isolated tissue, increased cyclic adenosine monophosphate (cAMP) concentrations in rat bladder tissue and showed a bladder relaxant effect in rat urinary bladder function models. Mirabegron increased mean voided volume per micturition, and decreased the frequency of non-voiding contractions, without affecting voiding pressure or residual urine in rat models of bladder overactivity. In a monkey model, mirabegron showed decreased voiding frequency. These results indicate that mirabegron enhances urine storage function by stimulating beta 3-adrenoceptors in the bladder.
During the urine storage phase, when urine accumulates in the bladder, sympathetic nerve stimulation predominates. Noradrenaline is released from nerve terminals, leading predominantly to beta adrenoceptor activation in the bladder musculature and hence bladder smooth muscle relaxation. During the urine voiding phase, the bladder is predominantly under parasympathetic nervous system control. Acetylcholine, released from pelvic nerve terminals, stimulates cholinergic M2 and M3 receptors, inducing bladder contraction. The activation of the M2 pathway also inhibits beta 3-adrenoceptor induced increases in cAMP. Therefore beta 3-adrenoceptor stimulation should not interfere with the voiding process. This was confirmed in rats with partial urethral obstruction, where mirabegron decreased the frequency of non-voiding contractions without affecting the voided volume per micturition, voiding pressure or residual urine volume.
Mirabegron exerts its pharmacologic effects by forcing bladder smooth muscle to relax, thereby expanding its capacity and relieving urgency. Mirabegron does not appear to adversely affect the mean maximum flow rate or mean detrusor pressure at maximum flow rate in patients with lower urinary tract symptoms and bladder outlet obstruction (BOO), but should be used with in patients with BOO due to reports of significant urinary retention. Furthermore, mirabegron increases both blood pressure and heart rate in a dose-dependent manner and should therefore be used with caution in patients with severely uncontrolled hypertension or others for whom these increases may prove dangerous.
Solifenacin is a competitive muscarinic (acetylcholine) receptor antagonist. The binding of acetylcholine to these receptors, particularly the M3 receptor subtype, plays a critical role in the contraction of smooth muscle. By preventing the binding of acetylcholine to these receptors, solifenacin reduces smooth muscle tone in the bladder, allowing the bladder to retain larger volumes of urine and reducing the number of incontinence episodes.
Solifenacin antagonizes the M2 and M3 muscarinic receptors in the bladder to treat an overactive bladder. It has a long duration of action as it is usually taken once daily. Patients taking solifenacin should be aware of the risks of angioedema and anaphylaxis.
| Trade Name | Megatas Plus |
| Generic | Solifenacin + Mirabegron |
| Weight | 5mg, 50mg |
| Type | Combikit Tablet |
| Therapeutic Class | |
| Manufacturer | Intas Pharmaceuticals Ltd |
| Available Country | India |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Mirabegron is a beta-3 adrenergic agonist used for the treatment of overactive bladder (OAB) with symptoms of urge urinary incontinence, urgency, and urinary frequency.
Mirabegron, in combination with the muscarinic antagonist solifenacin succinate, is used for the treatment of OAB with symptoms of urge urinary incontinence, urgency, and urinary frequency
Symptomatic treatment of urge incontinence and/or increased urinary frequency and urgency as may occur in patients with overactive bladder syndrome.
Megatas Plus is also used to associated treatment for these conditions: Neurogenic Detrusor Overactivity, Urinary Bladder, OveractiveBenign Prostatic Hyperplasia (BPH), Urinary Bladder, Overactive
How Megatas Plus works
Mirabegron is a potent and selective agonist of beta-3 adrenergic receptors. The activation of beta-3 receptors relaxes detrusor smooth muscle during the storage phase of the urinary bladder fill-void cycle, which increases the bladder's storage capacity thereby alleviating feelings of urgency and frequency.
Solifenacin is a competitive muscarinic receptor antagonist. It has the highest affinity for M3, M1, and M2 muscarinic receptors. 80% of the muscarinic receptors in the bladder are M2, while 20% are M3. Solifenacin's antagonism of the M3 receptor prevents contraction of the detrusor muscle, while antagonism of the M2 receptor may prevent contraction of smooth muscle in the bladder.
Dosage
Megatas Plus dosage
Recommended starting dose: 25 mg once daily, alone or in combination with solifenacin succinate 5 mg, once daily. Based on individual efficacy and tolerability, may increase dose to 50 mg once daily, alone or in combination with solifenacin succinate 5 mg, once daily. Swallow whole with water, with or without food, do not chew, divide or crush
Patients with Severe Renal Impairment or Patients with Moderate HepaticImpairment: Maximum dose is 25 mg Mirabegron once daily
Patients with End Stage Renal Disease (ESRD) or Patients with SevereHepatic Impairment: Not recommended
Adults, including the elderly: The recommended dose is Solifenacin Succinate 5 mg once daily. If needed, the dose may be increased to Solifenacin Succinate 10 mg once daily.
Children and adolescents: Safety and effectiveness in children have not yet been established. Therefore, Solifenacin Succinate should not be used in children.
Side Effects
The most common adverse reactions reported for patients treated with Mirabegron 50 mg during the three 12-week phase 3 double-blind, placebo-controlled studies are tachycardia and urinary tract infections. The frequency of tachycardia was 1.2% in patients receiving Mirabegron 50 mg. Tachycardia led to discontinuation in 0.1% patients receiving Mirabegron 50 mg. The frequency of urinary tract infections was 2.9% in patients receiving Mirabegron 50 mg. Urinary tract infections led to discontinuation in none of the patients receiving Mirabegron 50 mg. Serious adverse reactions included atrial fibrillation (0.2%).
The most common side effects are blurred vision, dry mouth, constipation & heat prostration. Other side effects include dizziness, fatigue, edema, palpitation and skin reactions. Disorientation, hallucination and convulsion may occur.
Toxicity
At doses of up to 400mg in healthy volunteers (~8x the recommended maximum), reported symptoms of overdose included palpitations and increased heart rate. Symptoms of chronic overdosage are similar in presentation and may also include a rise in systolic blood pressure. In cases of overdosage, employ standard symptomatic and supportive measures in addition to ECG monitoring.
The LD50 of Solifenacin has yet to be determined.
Signs of overdose include severe anticholinergic effects, mental status changes, and decreased consciousness. In case of overdose, treat patients with gastric lavage and supportive measures. Monitor patients with an ECG.
Precaution
Other causes of frequent urination (heart failure or renal disease) should be assessed before treatment with Solifenacin. If urinary tract infection is present, an appropriate antibacterial therapy should be started. Solifenacin Succinate should be used with caution in patients with clinically significant bladder outflow obstruction at risk of urinary retention, gastrointestinal obstructive disorders, risk of decreased gastrointestinal motility, severe renal impairment (creatinine clearance 30 ml/min), moderate hepatic impairment, concomitant use of a strong CYP3A4 inhibitor, e.g. ketoconazole
Interaction
The effect of co-administered medicinal products on the pharmacokinetics of mirabegron and the effect of mirabegron on the pharmacokinetics of other medicinal products was studied in single- and multiple-dose studies. Most drug-drug interactions were studied using a dose of mirabegron 100 mg given as oral controlled absorption system (OCAS) tablets. Interaction studies of mirabegron with metoprolol and with metformin used mirabegron immediate-release (IR) 160 mg.
Clinically relevant drug interactions between mirabegron and medicinal products that inhibit, induce or are a substrate for one of the CYP isozymes or transporters are not expected, except for the inhibitory effect of mirabegron on the metabolism of CYP2D6 substrates.
Concomitant medication with other drugs with anticholinergic properties may result in more pronounced therapeutic effects and side effects. The therapeutic effect of solifenacin may be reduced by concomitant administration of cholinergic receptor agonists. Solifenacin can reduce the effect of drugs that stimulate the motility of the gastro-intestinal tract, such as metoclopramide and cisapride. Ketoconazole & other CYP3A4 inhibitors increase the plasma concentration of solifenacin.
Volume of Distribution
Following intravenous administration, mirabegron has an apparent steady-state volume of distribution (Vd) of 1670 L indicating extensive distribution.
The volume of distribution of solifenacin is 600L.
Elimination Route
The absolute bioavailability of orally administered mirabegron ranges from 29% at a dose of 25 mg to 35% at a dose of 50 mg. The Tmax for the extended-release tablet and suspension formulations are approximately 3.5 hours, while the Tmax for the granule formulation is 4-5 hours. Both Cmax and AUC increase more than dose proportionally - an increase in dose from 50mg to 100mg results in a 2.9- and 2.6-fold increase in Cmax and AUC, respectively, whereas an increase from 50mg to 200mg results in a 8.4- and 6.5-fold increase in Cmax and AUC, respectively.
Steady-state concentrations of mirabegron are achieved after approximately 7 days of once-daily administration.
Solifenacin is well absorbed in the duodenum, jejunum, and ileum but not the stomach. Absorption occurs via passive diffusion and so no transporters are involved. The mean oral bioavailability of solifenacin is 88%. The Tmax of solifenacin is 3-8 hours with a Css of 32.3ng/mL for a 5mg oral dose and 62.9ng/mL for a 10mg oral dose.
Half Life
The mean terminal elimination half-life of mirabegron in adults being treated for overactive bladder is approximately 50 hours. In pediatric patients receiving the granule formulation for the treatment of neurogenic detrusor overactivity, the mean terminal elimination half-life is approximately 26-31 hours.
The elimination half life of solifenacin ranges from 33-85 hours.
Clearance
Total plasma clearance following intravenous administration is approximately 57 L/h, with renal clearance accounting for roughly 25% at approximately 13 L/h.
The clearance of solifenacin is 7-14L/h and a renal clearance of 0.67-1.51L/h.
Elimination Route
Of a 160mg radiolabeled dose administered to healthy volunteers, approximately 55% of the radioactivity was recovered in the urine and 34% in the feces. Approximately 25% of unchanged mirabegron was recovered in the urine while 0% was recovered in the feces.
Renal elimination is achieved primarily via active tubular secretion with some contribution by glomerular filtration.
69.2±7.8% of a radiolabelled dose is recovered in the urine, 22.5±3.3% was recovered in feces, and 0.4±7.8% was recovered in exhaled air. 18% of solifenacin is eliminated as the N-oxide metabolite, 9% is eliminated as the 4R-hydroxy N-oxide metabolite, and 8% is eliminated as the 4R-hydroxy metabolite.
Pregnancy & Breastfeeding use
Use in Pregnancy: There are limited amount of data from the use of Mirabegron in pregnant women. Studies in animals have shown reproductive toxicity. Mirabegron is not recommended during pregnancy and in women of childbearing potential not using contraception.
Use in Lactation: Mirabegron is excreted in the milk of rodents and therefore, is predicted to be present in human milk. No studies have been conducted to assess the impact of mirabegron on milk production in humans, its presence in human breast milk, or its effects on the breast-fed child. Mirabegron should not be administered during breast-feeding
Use in pregnancy: There are no adequate data from the use of solifenacin succinate in pregnant women. Caution should be exercised while prescribing solifenacin to pregnant women.
Use in lactating mother: No data concerning the excretion of solifenacin into breast milk are available. The use of Solifenacin is avoided in lactating mother.
Contraindication
Mirabegron is contraindicated in patients with: Hypersensitivity to the active substance or to any of the excipients. Severe uncontrolled hypertension defined as systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥110 mmHg.
Solifenacin is contraindicated in patients with hypersensitivity to solifenacin or to any of the excipients. It is also contraindicated in myasthenia gravis, urinary retention, uncontrolled narrow angle glaucoma, severe gastro-intestinal condition (including toxic megacolon), patients undergoing haemodialysis, patients with severe hepatic impairment, patients with severe renal impairment or moderate hepatic impairment and on treatment with a strong CYP3A4 inhibitor, e.g. ketoconazole.
Special Warning
Renal and Hepatic Impairment: Mirabegron has not been studied in patients with end stage renal disease
Gender: No dose adjustment is necessary according to gender.
Children: The safety and efficacy of mirabegron in children below 18 years of age have not yet been established. No data are available.
Patients with renal impairment: No dosage adjustment is necessary for patients with mild to moderate renal impairment (creatinine clearance > 30 ml/min). Patients with severe renal impairment (creatinine clearance 30 ml/min) should be treated with caution and receive no more than 5 mg Solifenacin SuccinateTablet once daily.
Patients with hepatic impairment: No dosage adjustment is necessary for patients with mild hepatic impairment. Patients with moderate hepatic impairment should be treated with caution and receive no more than 5 mg Solifenacin SuccinateTablet once daily.
Patients taking CYP3A4 inhibitors concomitantly: The maximum dose of Solifenacin Succinateshould be limited to 5 mg when treated simultaneously with ketoconazole or other potent CYP3A4 inhibitors e.g. ritonavir, nelfinavir or itraconazole.
Use in children: Safety and efficacy of solifenacin in children have not been established.
Acute Overdose
Mirabegron has been administered to healthy volunteers at single doses up to 400 mg. At this dose, adverse events reported included palpitations (1 of 6 subjects) and increased pulse rate exceeding 100 beats per minute (bpm) (3 of 6 subjects). Multiple doses of mirabegron up to 300 mg daily for 10 days showed increases in pulse rate and systolic blood pressure when administered to healthy volunteers. Treatment for overdose should be symptomatic and supportive. In the event of an overdosage, pulse rate, blood pressure and ECG monitoring is recommended.
Storage Condition
Store in a cool and dry place, protected from light.
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