Consumer medicine information

Metermine

Phentermine

BRAND INFORMATION

Brand name

Metermine

Active ingredient

Phentermine

Schedule

Metermine®

Metermine^®

 Consumer Medicine Information (CMI) summary

The full CMI on the next page has more details. If you are worried about using this medicine, speak to your doctor or pharmacist.

 1. Why am I using Metermine?

Metermine contains the active ingredient phentermine. Metermine is used to reduce body weight in obese or overweight patients. For more information, see Section 1. Why am I using Metermine? in the full CMI.

 2. What should I know before I use Metermine?

Do not use if you have ever had an allergic reaction to phentermine or any of the ingredients listed at the end of the CMI.

There are a number of circumstances in which a person should not use this medicine or may need to use caution. It is important to understand if these apply to you before taking Metermine (see the full CMI for more details).

Talk to your doctor if you have any other medical conditions, take any other medicines, or are pregnant or plan to become pregnant or are breastfeeding.

For more information, see Section 2. What should I know before I use Metermine? in the full CMI.

 3. What if I am taking other medicines?

Some medicines may interfere with Metermine and affect how it works.

A list of these medicines is in Section 3. What if I am taking other medicines? in the full CMI.

 4. How do I use Metermine?

Carefully follow all directions given by your doctor or other healthcare professionals and never change the dose yourself.
The usual dose of Metermine is one capsule a day.
Swallow the capsule whole with plenty of water. Do not chew or open the capsules.

More instructions can be found in Section 4. How do I use Metermine? in the full CMI.

 5. What should I know while using Metermine?

Things you should do	Remind any doctor, dentist, or pharmacist you visit that you are using Metermine. If you are going to have surgery, tell the surgeon or anaesthetist that you are taking Metermine. Stop taking and contact your doctor immediately if you become pregnant while taking Metermine. Tell your doctor immediately if you experience sudden or rapid weight loss, difficulty breathing, chest pain, fainting, and swelling of the lower limbs or if you cannot exercise as much as you usually can.
Things you should not do	Do not take Metermine to treat any other conditions unless your doctor tells you to. Do not give your medicine to anyone else, even if they have the same condition as you.
Driving or using machines	Be careful before you drive or use any machines or tools until you know how Metermine affects you.
Drinking alcohol	Do not drink alcohol whilst taking Metermine.
Looking after your medicine	Keep your capsules in the blister-foil pack until it is time to take them. Store in a cool dry place where the temperature stays below 30°C and keep out of reach of children.

For more information, see Section 5. What should I know while taking Metermine? in the full CMI.

 6. Are there any side effects?

Common side effects include changes in your heartbeat, high blood pressure, restlessness, trouble sleeping, nervousness, tremor, headache, dizziness, fainting, nausea, vomiting, diarrhoea or constipation, stomach cramps, dry or unpleasant taste in mouth, trouble urinating, skin rashes, sexual function problems, feelings of extreme happiness followed by depression and tiredness.

Serious side effects include heart attack, stroke, chest pain, myocardial infarction and difficulty breathing.

For more information, including what to do if you have any side effects, see Section 6. Are there any side effects? in the full CMI.

Metermine^®

Active ingredient(s): Phentermine (fen-ter-mean)

 Consumer Medicine Information (CMI)

This leaflet provides important information about using Metermine. You should also speak to your doctor or pharmacist if you would like further information or if you have any concerns or questions about taking Metermine.

Where to find information in this leaflet:

1. Why am I taking Metermine?
2. What should I know before I take Metermine?
3. What if I am taking other medicines?
4. How do I take Metermine?
5. What should I know while taking Metermine?
6. Are there any side effects?
7. Product details

 1. Why am I taking Metermine?

Metermine contains the active ingredient phentermine. Phentermine is combined with a resin which slowly releases the phentermine so the effect of Metermine lasts all day.

Metermine is used to reduce body weight in obese or overweight patients.

Metermine is an appetite suppressant that works by directly affecting the area of the brain that controls your appetite making you feel less hungry.

Metermine should be used as a part of an overall weight management plan, which includes a medically controlled diet and exercise program.

Your doctor will assess whether Metermine is suitable for you.

 2. What should I know before I take Metermine?

Warnings

Do not use Metermine if:

You are allergic to phentermine, or any of the ingredients listed at the end of this leaflet. Always check the ingredients to make sure you can use this medicine. Some of the symptoms of an allergic reaction may include:
- shortness of breath
- wheezing or difficulty breathing
- swelling of the face, lips, tongue, or other parts of the body
- rash, itching or hives on the skin.
You are taking any similar medicines to reduce weight.
You have any of the following medical conditions:
- very high blood pressure
- high blood pressure in the lungs
- problems with your heart valves
- disease related to blood vessels in the brain
- severe heart disease including changes in the rhythm or rate of the heartbeat
- narrowing of the blood vessels due to thickening or hardening of the blood vessel wall
- overactive thyroid gland
- psychiatric illness including anorexia nervosa (loss of appetite) and depression
- glaucoma (high pressure in the eye).
It is past the expiry date printed on the pack or if the packaging is torn or shows signs of tampering.
You are a child under the age of 12 years. Safety and effectiveness in children younger than 12 years have not been established.
You are elderly.
You are currently taking, or have taken within the last 14 days, antidepressant medicines called mono-amine oxidase inhibitors (MAOIs).
You have previously misused drugs or alcohol.

Check with your doctor if you:

Have any other medical conditions including:
- high blood pressure
- heart disease such as angina (chest pain)
- diabetes
- epilepsy
Take any medicines for any other condition.

During treatment, you may be at risk of developing certain side effects. It is important you understand these risks and how to monitor for them. See additional information under Section 6. Are there any side effects?

Pregnancy and breastfeeding

Check with your doctor if you are pregnant or intend to become pregnant.

Talk to your doctor if you are breastfeeding or intend to breastfeed.

 3. What if I am taking other medicines?

Tell your doctor or pharmacist if you are taking any other medicines, including any medicines, vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines may interfere with Metermine and affect how it works.

These include:

other medicines for weight reduction
medicines for depression or obsessive-compulsive disorder or other mental illness
ergot-like medicines for migraine
some cough and cold remedies
thyroid hormones
medicines for lowering high blood pressure.

Check with your doctor or pharmacist if you are not sure about what medicines, vitamins or supplements you are taking and if these affect Metermine.

 4. How do I take Metermine?

How much to take

The usual dose is one capsule a day, however your doctor will prescribe the right dose for you.
Swallow the capsules whole with plenty of water. Do not chew or open the capsules.
Carefully follow the instructions provided and use Metermine until your doctor tells you to stop.
Increasing the dose may not necessarily make you lose more weight or make you lose weight faster. However, you will more likely experience side effects. Your doctor will tell you how long you are to take Metermine for.

When to take Metermine

Take Metermine first thing in the morning, at breakfast time so that it does not keep you awake at night.
Taking Metermine at the same time each day will have the best effect. It will also help you remember when to take it. It does not matter if you take this medicine before or after food.
Do not change the dose unless your doctor tells you to do so.

If you forget to use Metermine

Metermine should be used regularly at the same time each day. If you miss your dose at breakfast, take it no later than lunchtime.

If you take Metermine any later than lunchtime you may have trouble sleeping at night.

If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to.

Do not take a double dose to make up for the dose you missed.

If you use too much Metermine

If you think that you have taken too much Metermine, you may need urgent medical attention.

You should immediately:

phone the Poisons Information Centre
(by calling 13 11 26 in Australia or 0800 764 766 [0800 POISON] in New Zealand), or
contact your doctor, or
go to the Emergency Department at your nearest hospital.

You should do this even if there are no signs of discomfort or poisoning.

 5. What should I know while taking Metermine?

Things you should do

Remind any doctor, dentist or pharmacist you visit that you are taking Metermine.
If you are going to have surgery, tell the surgeon or anaesthetist that you are taking Metermine.
Check with your doctor or pharmacist before you start to take any cough or cold medication.

Call your doctor straight away if you:

Become pregnant while taking this medicine.
Experience sudden or rapid weight loss, difficulty breathing, chest pain, fainting, and swelling of the lower limbs and if you cannot exercise as much as you usually can.

Things you should not do

Do not take Metermine to treat any other conditions unless your doctor tells you to.
Do not give your medicine to anyone else, even if they have the same condition as you.

Driving or using machines

Be careful before you drive or use any machines or tools until you know how Metermine affects you.

Drinking alcohol

Tell your doctor if you drink alcohol.

Do not drink alcohol whilst taking Metermine.

Looking after your medicine

Follow the instructions in the carton on how to take care of your medicine properly.

Keep your capsules in the blister-foil in the carton until it is time to take them.
Store Metermine below 30°C in a cool dry place away from moisture, heat, or sunlight; for example, do not store it:
- in the bathroom or near a sink, or
- in the car or on windowsills.

Keep it where young children cannot reach it.

Getting rid of any unwanted medicine

If you no longer need to use this medicine or it is out of date, take it to any pharmacy for safe disposal.

Do not use this medicine after the expiry date.

 6. Are there any side effects?

All medicines can have side effects. If you do experience any side effects, most of them are minor and temporary. However, some side effects may need medical attention.

See the information below and, if you need to, ask your doctor or pharmacist if you have any further questions about side effects.

Less serious side effects

Less serious side effects

What to do

feeling more awake than usual and trouble sleeping
your heart seems to beat faster and harder
your blood pressure may be raised slightly
irregular heart beats
feeling restless
feelings of extreme happiness followed by depression and tiredness
nervousness
tremor (shaking)
headache
dizziness
fainting
nausea
vomiting
diarrhoea or constipation
stomach cramps
dry mouth or an unpleasant taste in your mouth
if you cannot exercise as much as you usually can
difficulty passing urine
skin rashes
impotence
changes in sexual drive
swelling of the lower limbs
swelling of the face
sudden or rapid weight loss

Speak to your doctor if you have any of these less serious side effects and they worry you.

Serious side effects

Serious side effects	What to do
heart attack stroke chest pain myocardial infarction difficulty breathing	Call your doctor straight away, or go straight to the Emergency Department at your nearest hospital if you notice any of these serious side effects.

Tell your doctor or pharmacist if you notice anything else that may be making you feel unwell.

Other side effects not listed here may occur in some people.

Reporting side effects

After you have received medical advice for any side effects you experience, you can report side effects to the Therapeutic Goods Administration online at www.tga.gov.au/reporting-problems in Australia, or Medsafe at www.medsafe.govt.nz/safety/report-a-problem.asp in New Zealand.

By reporting side effects, you can help provide more information on the safety of this medicine.

Always make sure you speak to your doctor or pharmacist before you decide to stop taking any of your medicines.

 7. Product details

This medicine is only available with a doctor's prescription.

What Metermine contains

Active ingredient (main ingredient)	Phentermine
Other ingredients (inactive ingredients)	lactose monohydrate liquid paraffin magnesium stearate gelatin capsules hard PI (1947) titanium dioxide iron oxide black (CI 77499) sodium polystyrene sulfonate In addition: Metermine 15 mg contains: brilliant blue FCF (CI 42090) iron oxide yellow (CI 77492) Metermine 30 mg contains: iron oxide red (CI 77491) *Metermine 40 mg contains:** erythrosine (CI 45430) sunset yellow FCF (CI 5985)
Potential allergens	Contain sugars as lactose monohydrate

*Not available in New Zealand.

Do not take this medicine if you are allergic to any of these ingredients.

Metermine capsules are gluten-free.

What Metermine looks like

Metermine capsules are available in three strengths in packs of 30 capsules:

15 mg - AUST R 101828

Grey and green and marked METERMINE 15

30 mg - AUST R 101829

Grey and reddish brown and marked METERMINE 30

40 mg - AUST R 101830

Grey and orange and marked METERMINE 40

Who distributes Metermine

Australia

iNova Pharmaceuticals (Australia) Pty Limited
Level 10, 12 Help Street
Chatswood NSW 2067
Tel: 1800 630 056

New Zealand

iNova Pharmaceuticals (New Zealand) Pty Limited
Auckland
Tel: 0508 375 394

This leaflet was prepared in June 2022.

Published by MIMS July 2022

BRAND INFORMATION

Brand name

Metermine

Active ingredient

Phentermine

Schedule

1 Name of Medicine

Phentermine.

2 Qualitative and Quantitative Composition

Each Metermine capsule contains phentermine as an ion-exchange resin complex equivalent to 15, 30 or 40 mg phentermine depending on strength. The ion-exchange resin is quite stable, highly insoluble and without pharmacological effect until it reacts with cations (hydrogen, potassium, sodium etc) present in the gastrointestinal fluids. Phentermine is then released from the resin complex at a rate dependent on the total concentration of these cations. Since this concentration is fairly constant throughout the entire gastrointestinal tract, continuous and controlled ionic release occurs over a 10 to 14 hour period.
Each Metermine capsule also contains, as inactive ingredients, lactose monohydrate, liquid paraffin, magnesium stearate, gelatin, capsules hard PI (1947), titanium dioxide, iron oxide black (CI 77499) and sodium polystyrene sulfonate. In addition, Metermine 15 also contains brilliant blue FCF (CI 42090), iron oxide yellow (CI 77492); Metermine 30 also contains iron oxide red (CI 77491); Metermine 40 also contains erythrosine (CI 45430) and sunset yellow FCF (CI 15985).
Metermine capsules are gluten-free.

Excipient with known effect.

Each modified-release capsule contains sugars as lactose monohydrate.

3 Pharmaceutical Form

Modified-release capsule.

15 mg capsule.

Grey and green, marked Metermine 15 on cap and body.

30 mg capsule.

Grey and reddish brown, marked Metermine 30 on cap and body.

40 mg capsule.

Grey and orange, marked Metermine 40 on cap and body.

4 Clinical Particulars

4.1 Therapeutic Indications

Metermine is an anorectic agent indicated in the management of obesity as a short-term adjunct in a medically monitored comprehensive regimen of weight reduction based, for example, on exercise, diet (caloric/kilojoule restriction) and behaviour modification in obese patients with a body mass index (BMI) of 30 kg/m² or greater. The treatment with Metermine can be initiated in overweight patients with a lower BMI (25 to 29.9 kg/m²), which increases the risk of morbidity from a number of disorders. Secondary organic causes of obesity should be excluded by diagnosis before prescribing this agent.

4.2 Dose and Method of Administration

Adults and adolescents over 12 years.

One capsule daily at breakfast, swallowed whole. Evening dosing should be avoided, as this agent may induce insomnia. It is recommended that treatment should be initiated under the care of physicians experienced in the treatment of obesity.
The recommended starting dose is 30 mg daily. Larger framed individuals may require 40 mg daily. The recommended maintenance dose, either continuous or intermittent is 15 to 40 mg daily depending on responsiveness. The recommended dose of Metermine should not be exceeded to increase the effect. Metermine should not be combined with other appetite suppressants. Patients require medical review after a defined course of treatment, which should not exceed three months.

Children under 12 years.

Metermine is not recommended for children under the age of 12 years as safety and efficacy have not been established.

Elderly.

Metermine is not recommended for the elderly.

4.3 Contraindications

Pulmonary artery hypertension.
Existing heart valve abnormalities or heart murmurs.
Moderate to severe arterial hypertension.
Cerebro-vascular disease.
Severe cardiac disease including arrhythmias, advanced arteriosclerosis.
Known hypersensitivity to sympathomimetic drugs.
Hyperthyroidism.
Agitated states or a history of psychiatric illnesses including anorexia nervosa and depression.
Glaucoma.
History of drug/alcohol abuse or dependence.
Concomitant treatment with Monoamine Oxidase (MAO) Inhibitors or within 14 days following their administration.

4.4 Special Warnings and Precautions for Use

Metermine capsules are indicated only as short-term monotherapy for the management of exogenous obesity. The safety and efficacy of combination therapy with phentermine and any other drug products for weight loss have not been established. Therefore, coadministration of drug products for weight loss is not recommended.
Since the selective serotonin reuptake inhibitors (e.g. fluoxetine, sertraline, paroxetine), ergot-like drugs and clomipramine affect serotonin disposition there remains a theoretical risk that combination of these agents with phentermine may also be associated with cardiac valvular disease and is not recommended. There is no direct scientific evidence to confirm this theory.

Valvular heart disease.

Serious regurgitate cardiac valvular disease, primarily affecting the mitral, aortic and/or tricuspid valves, has been reported in otherwise healthy persons who had taken a combination of fenfluramine or dexfenfluramine with phentermine for weight loss. The aetiology of these valvulopathies has not been established and their course in individuals after the drugs are stopped is not known. There have been no reported cases to date of valvular heart disease occurring with the use of phentermine alone.

Primary pulmonary hypertension (PPH).

Cases of severe, sometime fatal primary pulmonary hypertension, have been reported in patients who have received anorectics. In a case-control epidemiological study, the duration of treatment with anorectic agents, not including phentermine, beyond three months significantly increases the risk of PPH. However, patients treated with phentermine require medical review at least every 3 months (see Section 4.2 Dose and Method of Administration). PPH has been reported in patients receiving fenfluramine/dexfenfluramine combined with phentermine. The possibility of an association between PPH and the use of phentermine alone cannot be ruled out; there have been very rare cases of PPH in patients who reportedly have taken phentermine alone. The initial symptom of PPH is usually dyspnoea. Other early symptoms include angina pectoris, syncope, lower extremity oedema or the unexplained onset or aggravation of diminished exercise tolerance. Under these circumstances, treatment should be immediately discontinued and the patient referred to a specialist unit for investigation.

Use with caution in the following circumstances.

Metermine should be used with caution in patients with mild hypertension. In the first days of treatment, determine that there is no loss of blood pressure control.
In patients receiving Metermine, response to insulin and oral hypoglycaemic agents may vary due to alterations in dietary regimes. This should be kept in mind if Metermine is used in diabetic patients.
Inappropriate use has been reported with similar drugs and the possibility of this occurrence should be considered with Metermine.
Cardiovascular and cerebrovascular events have rarely been reported, mainly in association with rapid weight loss. Weight loss should be gradual and controlled in obese patients undergoing treatment with Metermine. Metermine should be used with caution in patients with established coronary artery disease. A single case of exacerbation of angina pectoris in a patient with established coronary artery disease has been reported.
Metermine should be used with caution in patients receiving psychotrophic drugs, including sedatives and agents with sympathomimetic activity.
Metermine should be used with caution in epileptic patients.
Metermine should be used with caution in patients receiving anti-hypertensive agents.

Use in the elderly.

Metermine is not recommended for the elderly.

Paediatric use.

Metermine is not recommended for children.

Effects on laboratory tests.

There are no reports to date to suggest that phentermine interferes with laboratory or diagnostic tests.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Metermine should be used with caution in patients receiving sympathomimetic agents.
Metermine antagonises adrenergic neurone blocking drugs such as clonidine, methyldopa and guanethidine and may decrease their hypotensive effect.
The effects of Metermine are potentiated by Monoamine Oxidase Inhibitors (see Section 4.3 Contraindications) and may result in a hypertensive crisis.
The concurrent use of thyroid hormones with Metermine may increase the CNS stimulation that can occur with Metermine.
Alcohol may increase CNS side effects such as dizziness, light-headedness and confusion, and its concurrent use should be avoided with Metermine.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

In rats, administration of phentermine at a dose 10 times the maximum human dose on a mg/m² basis abolished oestrous cycling.
There is no information on the potential of phentermine to impair fertility in humans.
(Category B2)
Weight reduction using appetite suppression drugs is not recommended during pregnancy. In rats, administration of phentermine during late gestation at a dose 7 times the maximum human dose on a mg/m² basis had no adverse effects on dams or offspring. There is no information on the teratological potential of phentermine. Because of inadequate evidence of safety in human pregnancy, Metermine should not be used in pregnant women.
There is no data available on the safety of Metermine in lactation and as such, its use in lactating women should be avoided.

4.7 Effects on Ability to Drive and Use Machines

Metermine may impair the ability to perform activities requiring mental alertness, such as driving and operating machinery, and patients therefore should be cautioned accordingly.

4.8 Adverse Effects (Undesirable Effects)

Cardiovascular.

See Section 4.4 Special Warnings and Precautions for Use, Valvular heart disease, Primary pulmonary hypertension (PPH). The most common reported reactions are palpitations, tachycardia, elevation of blood pressure, precordial pain. Rare occurrences of cardiovascular or cerebrovascular events have been described with anorectic agents. In particular stroke, angina, myocardial infarction, cardiac failure and cardiac arrest have been reported.

Central nervous system.

Overstimulation, restlessness, nervousness, insomnia, tremor, dizziness and headache. Rarely euphoria may occur and this may be followed by fatigue and depression. Psychotic episodes and hallucinations are rare side effects.

Gastrointestinal.

Nausea, vomiting, dry mouth, abdominal cramps, unpleasant taste, diarrhoea, constipation.

Other.

Micturition disturbances, rash, impotence, changes in libido, facial oedema.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems.

4.9 Overdose

For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

Symptoms.

Initially irritability, rapid respiration, agitation, euphoria, restlessness, hyperreflexia, disorientation and tremor, aggressiveness, hallucinations and panic states may occur, followed by cardiac arrhythmias, convulsions, fatigue, central nervous system depression and coma. Cardiovascular consequences include hypertension, hypotension and circulatory collapse. Gastrointestinal symptoms include nausea, vomiting, diarrhoea and abdominal cramps.

Treatment.

The treatment is largely symptomatic. Activated charcoal may reduce absorption of the medicine if given within one or two hours after ingestion. In patients who are not fully conscious or have impaired gag reflex, consideration should be given to administering activated charcoal via a nasogastric tube, once the airway is protected. Diazepam, preferably by mouth (cautiously by intravenous injection) can be used to control marked excitement and convulsions. Provided renal function is adequate, elimination of phentermine has been shown to be assisted by acidification of the urine. There is insufficient experience to recommend haemodialysis or peritoneal dialysis.

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Phentermine is a sympathomimetic amine with significant anorectic activity in animal models. Its appetite suppressant effect is generally considered to be exerted through the hypothalamus, but it is not certain that this is the only effect related to weight loss. Phentermine has major effects on the dopaminergic and noradrenergic nervous systems. The cardiovascular effects include a pressor response and increase in heart rate and force of contraction.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties

Absorption.

Absorption of phentermine is almost complete. The rate of absorption from the resin complex is significantly slower than that from the hydrochloride salt resulting in a lower and later peak blood level. Phentermine is readily absorbed from the gastro-intestinal tract.

Metabolism and excretion.

Following an oral dose of phentermine capsule, one study demonstrated urinary excretion of unchanged drug ranging from 62.7% to 84.8% in 72 hours. The remainder is metabolised in the liver. The half-life of phentermine is about 25 hours. In one study in volunteers acidification of the urine reduced the half-life to 7 - 8 hours.

5.3 Preclinical Safety Data

Genotoxicity.

Phentermine was not mutagenic in a bacterial gene mutation assay, however, studies to assess the potential for chromosomal damage have not been performed.

Carcinogenicity.

No studies have been performed to determine the potential of phentermine for carcinogenesis.

6 Pharmaceutical Particulars

6.1 List of Excipients

See Section 2 Qualitative and Quantitative Composition.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Store below 30°C.

6.5 Nature and Contents of Container

Capsules supplied in PVC/PVDC blisters.
15 mg - 30's packs; 30 mg - 30's packs; 40 mg - 30's packs.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Chemical structure.

Phentermine (phenyl tertiary butylamine, C₁₀H₁₅N).

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Metermine

Phentermine

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BRAND INFORMATION

Metermine 15 mg Modified release capsules