Consumer medicine information




Brand name


Active ingredient





Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Duromine.

What is in this leaflet

This leaflet answers some common questions about Duromine. It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist. If you need any more information about Duromine please ask your doctor or pharmacist.

All medicines have risks and benefits. Your doctor has weighed the risk of you taking Duromine against the benefits it can have for you.

If you have any concerns about taking this medicine, ask your doctor or pharmacist.

Keep this leaflet with the medicine. You may want to read it again.

Your medicine

The name of your medicine is Duromine. Duromine capsules contain the active ingredient, phentermine. Phentermine is combined with a resin which slowly releases the phentermine so the effect of Duromine lasts all day.

What Duromine is used for

Duromine is used to reduce body weight in obese or overweight patients. Your doctor will assess whether Duromine is suitable for you. Duromine works by directly affecting the area of the brain that controls your appetite making you feel less hungry.

Ask your doctor if you have any questions about why this medicine has been prescribed for you.

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

Duromine is available only with a doctor's prescription.

Your doctor may prescribe Duromine for another purpose. If you are not sure why you are taking this medicine ask your doctor.

Before you take Duromine

When you must not take it

Do not take Duromine if you have an allergy to:

  • any medicine containing phentermine
  • any of the ingredients listed at the end of this leaflet
  • any other similar medicines used to reduce weight

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

Do not give this medicine to a child under the age of 12 years. Safety and effectiveness in children younger than 12 years have not been established.

Do not take this medicine if you have any of the following medical conditions:

  • very high blood pressure
  • high blood pressure in the lung
  • problems with the valves in your heart
  • disease related to blood vessels in the brain
  • severe heart disease including changes in the rhythm or rate of the heart beat
  • 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)

Do not use this medicine:

  • if you are currently taking, or have taken within the last 14 days, antidepressant medicines from the mono-amine oxidase inhibitor (MAOI) class such as phenelzine (eg Nardil) or tranylcypromine (eg Parnate).
  • if you have previously misused drugs or alcohol

Do not take this medicine after the expiry date printed on the pack or if the packaging is torn or shows signs of tampering. If it has expired or is damaged, return it to your pharmacist for disposal.

If you are not sure whether you should start taking this medicine, talk to your doctor.

Before you start to take it

Tell your doctor if you have allergies to any medicines, foods, preservatives or dyes.

Tell your doctor or pharmacist if you are pregnant or plan to become pregnant or are breast-feeding. Your doctor or pharmacist can discuss with you the risks and benefits involved.

Tell your doctor if you:

  • have high blood pressure
  • have heart disease such as angina (chest pain)
  • have diabetes
  • have epilepsy

If you have not told your doctor about any of the above, tell him/her before you start taking Duromine.

Taking other medicines

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

Some medicines and Duromine may interfere with each other. These include:

  • any medicines for weight reduction
  • any medicines for depression or obsessive compulsive disorder such as fluoxetine (eg Prozac, Erocap, Lovan, Zactin); sertraline (eg, Zoloft); paroxetine (eg Aropax); clomipramine (eg Anafranil, Placil)
  • ergot-like medicines for migraine such as ergotamine (eg Cafergot, Ergodryl, Migral)
  • any cough and cold remedies containing pseudoephedrine, phenylpropanolamine or phenylephrine
  • thyroid hormones
  • any medication for mental illness
  • medicines for lowering high blood pressure including clonidine, methyldopa or guanethidine.

These medicines may be affected by Duromine or may affect how well it works. You may need different amounts of your medicines, or you may need to take different medicines.

Your doctor and pharmacist have more information on medicines to be careful with or avoid while taking this medicine.

How to take Duromine

Carefully follow all directions given to you by your doctor or pharmacist and never change the dose yourself. They may differ from the information contained in this leaflet.

If you do not understand the instructions on the box, ask your doctor or pharmacist for help.

How much to take

In adults and adolescents over 12 years, the usual dose of Duromine is one capsule every day. However, your doctor will prescribe the right dose for you.

Increasing the dose may not necessarily make you lose more weight or make you lose weight faster. However you will most likely experience more side effects. Your doctor will tell you how long you are to take Duromine for.

How to take it

Swallow the capsules whole with plenty of water. Do not chew or open the capsules.

When to take it

Take Duromine first thing in the morning, at breakfast time so that it does not keep you awake at night.

Taking it 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.

Duromine is not recommended for elderly patients or for children younger than twelve years.

How long to take it

Take this medicine as long as your doctor tells you to.

If you forget to take it

If you forget to take your Duromine dose at breakfast take it no later than lunchtime. Alternatively, skip the dose you missed and take your next dose at the normal time on the next day. If you take Duromine any later than lunch-time you may have trouble sleeping at night.

Never take a double dose to make up for a dose you have missed.

If you have trouble remembering when to take your medicine, ask your pharmacist for some hints.

If you take too much Duromine

Immediately telephone your doctor or the Poisons Information Centre (Australia: telephone 13 11 26; New Zealand: 0800 POISON or 0800 764 766) for advice, or go to Accident and Emergency at the nearest hospital, if you think that you or anyone else may have taken too much Duromine. Do this even if there are not signs of discomfort or poisoning. You may need urgent attention.

While you are using Duromine

If you are about to be started on any new medicine remind your doctor and pharmacist that you are taking Duromine.

Tell any other doctors, dentists and pharmacists who treat you that you are taking this medicine.

If you are going to have surgery, tell the surgeon or anaesthetist that you are taking this medicine.

If you become pregnant while taking this medicine, tell your doctor immediately.

Keep all of your doctor's appointments so that your progress can be checked.

Tell your doctor immediately if you 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 must not do

Do not take Duromine to treat any other complaints unless your doctor tells you to.

Do not give your medicine to anyone else, even if they have the same condition as you.

Things to be careful of

Be careful driving or operating machinery until you know how Duromine affects you.

DO NOT drink alcohol whilst taking Duromine.

Check with your doctor or pharmacist before you start to take any cough or cold medication.

Side Effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while taking Duromine.

This medicine helps most people with a weight problem but it may have unwanted side effects in a few people. All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical attention if you get some of the side effects.

Do not be alarmed by the following lists of side effects. You may not experience any of them.

Ask your doctor or pharmacist to answer any questions you may have.

Tell your doctor immediately or go to Accident and Emergency at your nearest hospital if you experience:

  • heart attack
  • stroke
  • angina
  • myocardial infarction

The above list includes very serious side effects. You may need urgent medical attention or hospitalisation. These side effects are rare.

Tell your doctor or pharmacist if you notice any of the following and they worry you:

  • feeling more awake than usual
  • trouble sleeping
  • your heart seems to beat faster and harder
  • your blood pressure may be raised slightly
  • irregular heart beats
  • chest pain
  • feeling restless
  • feelings of extreme happiness followed by depression and tiredness
  • nervousness
  • tremor (shaking)
  • headache
  • dizziness
  • nausea
  • vomiting
  • diarrhoea or constipation
  • stomach cramps

Tell your doctor as soon as possible if you notice any of the following:

  • sudden or rapid weight loss
  • difficulty breathing
  • chest pain
  • fainting
  • swelling of the lower limbs
  • or if you cannot exercise as much as you usually can
  • dry mouth or an unpleasant taste in your mouth
  • difficulty passing urine
  • skin rashes
  • impotence
  • changes in sexual drive
  • swelling of the face

Tell your doctor or pharmacist if you notice anything that is making you feel unwell.

Other side effects not listed above may also occur in some people.

After Using Duromine


Keep your capsules in the blister-foil in the carton until it is time to take them. If you take the capsules out of the pack they may not keep well.

Keep Duromine in a cool dry place where the temperature stays below 30°C.

Do not store Duromine or any other medicine in the bathroom or near a sink. Do not leave them on a windowsill or in the car. Heat and dampness can destroy some medicines.

Keep them where children cannot reach them. A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.


If your doctor tells you to stop taking this medicine or the expiry date has passed, ask your pharmacist what to do with any medicine that is left over.

Product Description

What Duromine looks like

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

15 mg - AUST R 10941
Grey and green and marked DUROMINE 15

30 mg - AUST R 76680
Grey and reddish brown and marked DUROMINE 30

40 mg - AUST R 10942
Grey and orange and marked DUROMINE 40

Duromine capsules are available in two strengths in packs of 7 capsules:

15 mg - AUST R 10941
Grey and green and marked DUROMINE 15

30 mg - AUST R 76680
Grey and reddish brown and marked DUROMINE 30


Duromine capsules contain:

  • phentermine
  • lactose monohydrate
  • liquid paraffin
  • magnesium stearate
  • gelatin capsules hard PI (1947)
  • titanium dioxide
  • iron oxide black (CI 77499)
  • sodium polystyrene sulfonate

In addition:

Duromine 15 mg contains:

  • brilliant blue FCF (CI 42090)
  • iron oxide yellow (CI 77492)

Duromine 30 mg contains:

  • iron oxide red (CI 77491)

Duromine 40 mg contains:

  • erythrosine (CI 45430)
  • sunset yellow FCF (CI 5985).

Duromine capsules are gluten-free.

Duromine capsules contain sugars as lactose monohydrate.


iNova Pharmaceuticals (Australia) Pty Limited
ABN: 13 617 871 539

Level 10, 12 Help Street
Chatswood NSW 2067
Tel (Australia): 1800 630 056
Tel (New Zealand): 0508 375 394

™ = Trademark

This leaflet was prepared in April 2021.

Published by MIMS June 2021


Brand name


Active ingredient





1 Name of Medicine


2 Qualitative and Quantitative Composition

Each Duromine 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 Duromine 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, Duromine 15 also contains brilliant blue FCF (CI 42090), iron oxide yellow (CI 77492); Duromine 30 also contains iron oxide red (CI 77491); Duromine 40 also contains erythrosine (CI 45430) and sunset yellow FCF (CI 15985).
Duromine 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 Duromine 15 on cap and body.
30 mg capsule - grey and reddish brown, marked Duromine 30 on cap and body.
40 mg capsule - grey and orange, marked Duromine 40 on cap and body.

4 Clinical Particulars

4.1 Therapeutic Indications

Duromine 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 Duromine 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 Duromine should not be exceeded to increase the effect. Duromine 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.

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


Duromine is not recommended for the elderly.

4.3 Contraindications

Pulmonary artery hypertension; existing heart valve abnormalities or heart murmurs; moderate to severe arterial hypertension; cerebrovascular 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

Duromine 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, sometimes 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.

Duromine 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 Duromine, response to insulin and oral hypoglycaemic agents may vary due to alterations in dietary regimens. This should be kept in mind if Duromine is used in diabetic patients.
Inappropriate use has been reported with similar drugs and the possibility of this occurrence should be considered with Duromine.
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 Duromine. Duromine 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.
Duromine should be used with caution in patients receiving psychotrophic drugs, including sedatives and agents with sympathomimetic activity.
Duromine should be used with caution in epileptic patients.
Duromine should be used with caution in patients receiving antihypertensive agents.

Use in the elderly.

Duromine is not recommended for the elderly.

Paediatric use.

Duromine 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

Duromine should be used with caution in patients receiving sympathomimetic agents.
Duromine antagonises adrenergic neurone blocking drugs such as clonidine, methyldopa and guanethidine and may decrease their hypotensive effect.
The effects of Duromine 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 Duromine may increase the CNS stimulation that can occur with Duromine.
Alcohol may increase CNS side effects such as dizziness, lightheadedness and confusion, and its concurrent use should be avoided with Duromine.

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, Duromine should not be used in pregnant women.
There is no data available on the safety of Duromine in lactation and as such, its use in lactating women should be avoided.

4.7 Effects on Ability to Drive and Use Machines

Duromine 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)


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.


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


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

4.9 Overdose

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


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.


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 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 gastrointestinal 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


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


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 - 3's#, 7's, 30's, 300's# packs.
30 mg - 3's#, 7's, 30's, 300's# packs.
40 mg - 3's#, 7's, 30's, 300's# packs.
# - Not currently distributed in Australia.

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).

CAS number.


7 Medicine Schedule (Poisons Standard)

S4 - Prescription Only Medicine.

Summary Table of Changes