Consumer medicine information

Cosamide 50



Brand name

Cosamide 50

Active ingredient





Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Cosamide 50.

What is in this leaflet

This leaflet answers some common questions about Cosamide 50.

It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist.

All medicines have benefits and risks. Your doctor has weighed the risks of you taking Cosamide 50 against the benefits expected for you.

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

Keep this leaflet with your medicine. You may need to read it again.

What Cosamide 50 is used for

Cosamide 50 is used in combination with other medicines to treat advanced prostate cancer.

Cosamide 50 is an anti-androgen medicine. Androgens such as testosterone are natural male sex hormones. In some types of prostate cancer, androgens may help the cancer cells to grow. Cosamide 50 interferes with some of the actions of these hormones.

Cosamide 50 should only be taken by men.

Ask your doctor if you have any questions about why this medicine has been prescribed for you. Your doctor may have prescribed it for another reason.

Cosamide 50 is available only with a doctor's prescription.

Cosamide 50 is not addictive.

Before you take Cosamide 50

When you must not take it

Do not take Cosamide 50 if you are a woman. Women are not normally treated with Cosamide 50.

Do not take Cosamide 50 if you have an allergy to:

  • any medicine containing bicalutamide
  • any of the ingredients listed at the end of this leaflet
  • any other anti-androgen 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.

Do not give Cosamide 50 to children. There is no experience of its use in children.

Do not take Cosamide 50 if you are taking cisapride or the antihistamines, terfenadine and astemizole.

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 other medicines, foods, preservatives or dyes.

Tell your doctor if you have liver problems. It may not be safe for you to take Cosamide 50 if you have problems with your liver.

If you have not told your doctor about any of the above, tell him/her before you start taking Cosamide 50.

Taking other medicines

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

Some medicines and Cosamide 50 may interfere with each other. These include:

  • cisapride
  • the antihistamines terfenadine and astemizole
  • medicines used to prevent blood clots, especially warfarin
  • midazolam
  • ciclosporin
  • medicines used to treat high cholesterol
  • calcium channel blockers, medicines used to treat high blood pressure
  • carbamazepine
  • quinidine
  • antiviral medicines for HIV infection
  • cimetidine
  • ketoconazole.

These medicines may be affected by Cosamide 50 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 Cosamide 50

Follow all directions given to you by your doctor and pharmacist carefully. They may differ from the information contained in this leaflet.

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

How much to take

The usual adult dose is one 50 mg tablet taken each day.

How to take it

Swallow the tablet whole with a glass of water.

When to take it

Take Cosamide 50 at about the same time each day. Taking it at the same time each day will have the best effect. It will also help you remember when to take it.

Cosamide 50 should be started at the same time as the other medicines you have been given for the treatment of prostate cancer.

It does not matter if you take Cosamide 50 before, with or without food.

How long to take it

Continue taking Cosamide 50 for as long as your doctor tells you to.

If you forget to take it

If it less than 12 hours before your next dose, skip the dose you missed and take your next dose when you are meant to.

Otherwise, take it as soon as you remember, and then go back to taking your medicine as you would normally.

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

If you are not sure what to do, ask your doctor or pharmacist.

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

If you take too much (overdose)

Immediately telephone your doctor, or the Poisons Information Centre (telephone 13 11 26), or go to Accident and Emergency at the nearest hospital, if you think that you or anyone else may have taken too much Cosamide 50. Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention.

While you are taking Cosamide 50

Things you must do

If you are about to be started on any new medicine, remind your doctor and pharmacist that you are taking Cosamide 50.

Tell any other doctors, dentists and pharmacists who treat you that you are taking Cosamide 50.

If you go into hospital, let the medical staff know you are taking Cosamide 50.

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

Things you must not do

Do not use Cosamide 50 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.

Do not stop taking your medicine or lower the dose without checking with your doctor.

Things to be careful of

Be careful driving or operating machinery until you know how Cosamide 50 affects you. Some people may feel dizzy or weak.

Side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking Cosamide 50. This medicine helps most people with prostate cancer, but it may have unwanted side effects in some 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 list 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 or pharmacist if you notice any of the following and they worry you:

  • hot flushes or sweating
  • breast tenderness or changes in breast size
  • itching or dry skin, rashes
  • increased hairiness or hair loss
  • stomach pain or indigestion
  • nausea or vomiting
  • diarrhoea or constipation
  • flatulence (wind)
  • dry mouth
  • loss of appetite or weight changes
  • depression
  • unusual tiredness or weakness
  • dizziness or light-headedness
  • difficulty sleeping
  • headache
  • chills
  • pelvic pain
  • decrease in your sexual drive
  • inability to get or maintain an erection.

The above list includes the more common side effects of Cosamide 50.

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

  • frequent urination
  • shortness of breath and dizziness when exercising and looking pale (anaemia)
  • excessive thirst with weight loss, and passing large amounts of urine.

The above list includes serious side effects which may require medical attention.

Tell your doctor immediately or go to Accident and Emergency at the nearest hospital if any of the following happen:

  • chest pain
  • yellowing of the skin or eyes and dark coloured urine
  • rash, hives or severe itching of the skin
  • swelling of the face, lips, tongue and/or throat, which may cause difficulty in swallowing
  • swelling of other parts of the body including hands, feet or ankles
  • serious breathlessness, or sudden worsening of breathlessness, possibly with a cough or fever
  • shortness of breath, wheezing or trouble breathing.

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

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 taking Cosamide 50


Keep your tablets in the pack until it is time to take them. If you take the tablets out of the pack they may not keep well.

Keep your tablets in a cool dry place where the temperature stays below 25°C.

Do not store Cosamide 50 or any other medicine in the bathroom or near a sink. Do not leave it on a window sill or in the car. Heat and dampness can destroy some medicines.

Keep it where children cannot reach it. 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 it looks like

Cosamide 50
50 mg tablets are white round, biconvex, film-coated tablets, with "B50" on one side and plain on the other side.

Each pack contains 28 tablets.


Each Cosamide 50 tablet contains 50 mg of bicalutamide as the active ingredient.

The tablets also contain the following inactive ingredients:

  • lactose monohydrate
  • povidone
  • sodium starch glycollate type A
  • magnesium stearate
  • hypromellose
  • macrogol 400
  • titanium dioxide.

The tablets do not contain sucrose, gluten, tartrazine or any other azo dyes. The tablets contain lactose.


Cosamide 50 is supplied in Australia by:

Alphapharm Pty Ltd
Level 1, 30 The Bond
30-34 Hickson Road
Millers Point NSW 2000

Australian registration number:
AUST R 162829 (blister pack)

This leaflet was prepared in
September 2020.

Cosamide 50_cmi\Sep20/00

Published by MIMS November 2020


Brand name

Cosamide 50

Active ingredient





1 Name of Medicine


2 Qualitative and Quantitative Composition

Each Cosamide 50 tablet contains 50 mg of bicalutamide.
Bicalutamide is a fine white to off-white powder. At 37°C it is practically insoluble in water (4.6 mg/litre), acid (4.6 mg/litre at pH 1) and alkali (3.7 mg/litre at pH 8). In organic solvents it is slightly soluble in ethanol, sparingly soluble in methanol and freely soluble in acetone and tetrahydrofuran.
Excipients with known effect: lactose monohydrate. For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

The tablets are white to off white, round, biconvex, film-coated tablets debossed "B50" on one side and plain on other side.

4 Clinical Particulars

4.1 Therapeutic Indications

Treatment of advanced prostate cancer in combination with Luteinising Hormone Releasing Hormone (LHRH) agonist therapy.
Prevention of disease flare associated with the use of LHRH agonists.

4.2 Dose and Method of Administration

Adult males including the elderly.

One tablet (50 mg) once a day.
Treatment with bicalutamide 50 mg should be started at the same time as treatment with a LHRH agonist.

Renal impairment.

No dosage adjustment is necessary for patients with renal impairment.

Hepatic impairment.

No dosage adjustment is necessary for patients with mild hepatic impairment.
Increased accumulation may occur in patients with moderate to severe hepatic impairment (see Section 4.4 Special Warnings and Precautions for Use). In such cases, a lower or less frequent dose may be considered.

4.3 Contraindications

Bicalutamide is contraindicated in females and children.
Known hypersensitivity to bicalutamide or any other constituents of the formulation.
Co-administration of terfenadine, astemizole or cisapride with bicalutamide is contraindicated (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions).

4.4 Special Warnings and Precautions for Use


A reduction in glucose tolerance has been observed in males receiving LHRH agonists. This may manifest as diabetes or loss of glycaemic control in those with pre-existing diabetes. Consideration should therefore be given to monitoring blood glucose in patients receiving bicalutamide in combination with LHRH agonists.

Potentiation of coumarin anticoagulant effects.

Potentiation of coumarin anticoagulant effects have been reported in patients receiving concomitant bicalutamide therapy, which may result in increased Prothrombin Time (PT) and International Normalised Ratio (INR). Some cases have been associated with risk of bleeding. Close monitoring of PT/INR is advised and anticoagulant dose adjustment should be considered (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions; Section 4.8 Adverse Effects (Undesirable Effects)).

Use in patients with metastatic prostate cancer.

In patients with metastatic prostate cancer, treatment with bicalutamide monotherapy has been associated with reduced survival compared to castration. Bicalutamide should therefore not be used without concomitant LHRH agonist therapy in these patients.

QT/QTc interval prolongation.

Androgen deprivation therapy may prolong QT/QTc interval. Prescribers should consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients with congenital long QT syndrome, congestive heart failure, frequent electrolyte abnormalities and in patients taking drugs known to prolong the QT interval. Electrolyte imbalances should be corrected. Consider periodic monitoring of electrocardiograms and electrolytes.

Use in hepatic impairment.

Bicalutamide is extensively metabolised in the liver. Data suggests that its elimination may be slower in subjects with severe hepatic impairment and this could lead to increased accumulation of bicalutamide. Therefore, bicalutamide should be used with caution in patients with moderate to severe hepatic impairment.
Periodic liver function testing should be considered due to the possibility of hepatic changes. The majority of these changes occur within the first 6 months of bicalutamide therapy.
Rare cases of death or hospitalisation due to severe liver injury have been observed with bicalutamide (see Section 4.8 Adverse Effects (Undesirable Effects)). Bicalutamide therapy should be discontinued if at any time a patient develops jaundice or if serum ALT rises above two times the upper limit of normal.

Use in renal impairment.

See Section 4.2 Dose and Method of Administration.

Use in the elderly.

See Section 4.2 Dose and Method of Administration.

Paediatric use.

No data available.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Bicalutamide is extensively metabolised (via oxidation and glucuronidation) in the liver. Bicalutamide has shown no evidence of causing enzyme induction in humans during dosing at 50 mg daily in man. In vitro studies have shown that R-bicalutamide is an inhibitor of CYP 3A4, with lesser inhibitory effects on CYP 2C9, 2C19 and 2D6 activity.
The clinically or potentially significant medicine interactions between bicalutamide and the following agents/ medicine classes, which are theoretical or have been observed, are described below. The medicine/ medicine interactions described include both interactions mediated through effects on P450 metabolism and interactions mediated through other mechanisms.

Effects of bicalutamide on other medicines.

LHRH agonists.

Although there is no evidence of any pharmacodynamic or pharmacokinetic interactions between bicalutamide 50 mg and LHRH agonists at steady state, bicalutamide 50 mg may prevent the harmful clinical consequences of flare associated with the start of LHRH agonist therapy.

Cytochrome P450.

Bicalutamide is an inhibitor of CYP 3A4 and has been shown to increase plasma levels of midazolam by up to 80%. Therefore, concomitant use of terfenadine, astemizole and cisapride is contraindicated. Caution should be exercised with other medicines metabolised by CYP 3A4, such as ciclosporin, calcium channel blockers, HIV antivirals, HMG-CoA reductase inhibitors, carbamazepine, quinidine, etc.

Demonstrated interactions.


In vitro studies have shown that bicalutamide can displace the coumarin anticoagulant, warfarin, from its protein binding sites. There have been reports of increased effect of warfarin and other coumarin anticoagulants when co-administered with bicalutamide. It is therefore recommended that if bicalutamide is administered in patients who are already receiving coumarin anticoagulants, PT/INR should be closely monitored and adjustments of anticoagulant dose considered (see Section 4.4 Special Warnings and Precautions for Use; Section 4.8 Adverse Effects (Undesirable Effects)).

Theoretical interactions.

Caution should be exercised when prescribing bicalutamide with other medicines which may inhibit medicine oxidation e.g. cimetidine and ketoconazole. In theory, this could result in increased plasma concentrations of bicalutamide and an increase in adverse effects.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

Administration of bicalutamide may lead to inhibition of spermatogenesis. The long-term effects of bicalutamide on male fertility have not been studied. Atrophy of seminiferous tubules of the testes, atrophy of the epididymis, and atrophy of the male reproductive glands are predicted class effects of antiandrogens and have been observed in rats at exposures less than the therapeutic concentrations at the recommended clinical dose of 50 or 150 mg. Reversal of seminiferous tubule and seminal vesicle atrophy occurred in most animals by 4 months after the completion of dosing in a 6-month rat study. In this study, prostate atrophy was not fully reversible by 4 months after the completion of dosing. No recovery of seminiferous tubule atrophy was observed at 24 weeks after the completion of dosing in a 12-month rat study. Following 12 months of repeated dosing in dogs, the incidence of testicular atrophy was the same in dosed and control dogs after a 6-month recovery period. In male rats dosed at 250 mg/kg/day (less than human therapeutic concentrations after the recommended clinical dose of 50 mg or 150 mg), the precoital interval and time to successful mating were increased in the first pairing but no effects on fertility following successful mating were seen. These effects were reversed by 7 weeks after the end of an 11 week period of dosing. A period of subfertility or infertility should be assumed in man.
Antiandrogen therapy may cause morphological changes in spermatozoa. Although the effect of bicalutamide on sperm morphology has not been evaluated and no such changes have been reported for patients who received bicalutamide, patients and/or their partners should follow adequate contraception during bicalutamide therapy and for 130 days after bicalutamide therapy.
(Category D)
Bicalutamide is contraindicated in females and must not be given to pregnant women.
Bicalutamide is contraindicated in females and must not be given to breast-feeding mothers.

4.7 Effects on Ability to Drive and Use Machines

During treatment with bicalutamide, somnolence has been reported. Those patients who experience this symptom should observe caution when driving or using machines.

4.8 Adverse Effects (Undesirable Effects)

Bicalutamide 50 mg in general, has been well tolerated with few withdrawals due to adverse events.

Clinical trial data - combination therapy (with medical castration) in advanced prostate cancer.

The following adverse experiences were reported in clinical trials (as possible adverse medicine effects in the opinion of investigating clinicians, with a frequency of ≥ 1%) during treatment with bicalutamide 50 mg plus an LHRH agonist. No causal relationship of these experiences to medicine treatment has been made and some of the experiences reported are those that commonly occur in elderly patients. (See Table 1.)

Increased PT/INR.

Accounts of coumarin anticoagulants interacting with bicalutamide have been reported in post marketing surveillance (see Section 4.5 Interactions with Other Medicines and Other Forms of Interactions; Section 4.4 Special Warnings and Precautions for Use).

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).
There is no human experience of overdosage. There is no specific antidote; treatment should be symptomatic. Dialysis may not be helpful, since bicalutamide is highly protein bound and is not recovered unchanged in the urine. General supportive care, including frequent monitoring of vital signs, is indicated.

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Bicalutamide is a non-steroidal anti-androgen, devoid of other endocrine activity. It binds to androgen receptors without activating gene expression, and thus inhibits the androgen stimulus. This inhibition impairs the growth and encourages apoptosis in androgen-dependent tumour cells and regression of prostatic tumours. In a subset of patients who experience disease progression while receiving bicalutamide, discontinuation of the medicine may result in an 'anti-androgen withdrawal syndrome', which manifests as a fall in prostate specific antigen (PSA) level. It is unknown whether this phenomenon translates to a prolongation of tumour response or survival.
Bicalutamide is a racemate with its anti-androgenic activity being almost exclusively in the (R)-enantiomer.

Clinical trials.

Combination therapy (with medical castration) in advanced prostate cancer.

In a large multicentre, controlled clinical trial, 813 patients with previously untreated advanced prostate cancer were randomised to receive bicalutamide 50 mg once daily (404 patients) or flutamide 250 mg (409 patients) three times a day, each in combination with a luteinising hormone releasing hormone agonist (LHRH agonist) (either goserelin acetate implant or leuprorelin acetate depot). At the time of analysis, the median time of follow-up was 49 weeks. Bicalutamide/ LHRH agonist therapy was associated with a statistically significant (p = 0.005) improvement in time to treatment failure.
Subjective responses, (including scores for pain, analgesic use and Eastern Oncology Cooperative Group (ECOG) performance status) assessed in patients with symptoms at entry were seen in 95 (52%) patients treated with bicalutamide and in 88 (54%) patients treated with flutamide, each in combination therapy with LHRH agonists. This small difference was not statistically significant between bicalutamide 50 mg combination therapy and flutamide combination therapy.


There is considerable debate regarding the relative merits of combination versus monotherapy in advanced prostate cancer, summarised by Dalesio et al 19951 in their meta-analysis of trials of maximal androgen blockade (MAB). This analysis showed no statistically significant reduction in the annual odds of death in favour of MAB. The meta-analysis included the effect of MAB only on mortality, and did not measure other end-points such as time to disease progression.
1Prostate Cancer Trialists' Collaborative Group. Maximum androgen blockade in advanced prostate cancer: an overview of 22 randomised trials with 3283 deaths in 5710 patients. Lancet 1995; 346: 265-269.

5.2 Pharmacokinetic Properties


Bicalutamide is well absorbed following oral administration. There is no evidence of any clinically relevant effect of food on bioavailability.


Bicalutamide is highly protein bound (racemate 96%, R-enantiomer 99.6%).
Steady-state plasma concentrations of the (R)-enantiomer of approximately 9 microgram per mL are observed during daily administration of bicalutamide 50 mg. At steady state the predominantly active (R)-enantiomer accounts for 99% of the total circulating enantiomers.


Bicalutamide undergoes stereospecific metabolism. Bicalutamide is extensively metabolised (via oxidation and glucuronidation).


Its metabolites are eliminated via the kidneys and bile in approximately equal proportions.
The (S)-enantiomer is rapidly cleared relative to the (R)-enantiomer, the latter having a plasma elimination half-life of about 1 week. On daily administration of bicalutamide, the (R)-enantiomer accumulates about 10-fold in plasma as a consequence of its long half-life.

Special populations.

The pharmacokinetics of the (R)-enantiomer are unaffected by age, renal impairment or mild to moderate hepatic impairment. There is evidence that for subjects with severe hepatic impairment, the (R)-enantiomer is more slowly eliminated from plasma.

5.3 Preclinical Safety Data


Bicalutamide was inactive in in vitro tests for gene mutation and in in vitro and in vivo tests for clastogenicity.


Two-year oral carcinogenicity studies were conducted in male and female rats and mice at doses of 5, 15 or 75 mg/kg/day of bicalutamide. A variety of tumour target organ effects were identified and were attributed to the anti-androgenicity of bicalutamide, namely, testicular benign interstitial (Leydig) cell tumours in male rats at all dose levels and uterine adenocarcinoma in female rats at 75 mg/kg/day (at these dose levels plasma (R)-bicalutamide concentrations were less than human therapeutic concentrations after the maximum recommended clinical dose of 150 mg). There is no evidence of Leydig cell hyperplasia in patients; uterine tumours are not relevant to the indicated patient population.
A small increase in the incidence of hepatocellular carcinoma in male mice given 75 mg/kg/day of bicalutamide (approximately 2 times human therapeutic concentrations after the maximum recommended clinical dose of 150 mg) and an increased incidence of benign thyroid follicular cell adenomas in rats given 5 mg/kg/day (less than the human therapeutic concentrations after the maximum recommended clinical dose of 150 mg) and above were recorded. These neoplastic changes were progressions of non-neoplastic changes related to hepatic enzyme induction observed in animal toxicity studies. Enzyme induction has not been observed following bicalutamide administration in man.

6 Pharmaceutical Particulars

6.1 List of Excipients

Each Cosamide 50 tablet contains the following excipients: lactose monohydrate, sodium starch glycollate type A, povidone, magnesium stearate, hypromellose, macrogol 400 and titanium dioxide.

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 25°C. Protect from moisture.

6.5 Nature and Contents of Container

Available in blister packs (PVC/PVDC/Al) of 28 tablets.

6.6 Special Precautions for Disposal

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

6.7 Physicochemical Properties

Chemical structure.

Chemical name: (RS)-4'-Cyano-α',α',α',-trifluoro-3- (4-fluorophenylsulfonyl)-2-hydroxy-2- methylpropiono-m-toluidide; propanamide,N-[4-cyano-3- (trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfonyl]-2- hydroxy-2-methyl-,(+-).
Structural formula:
Molecular formula: C18H14F4N2O4S. Molecular weight: 430.38.

CAS number.


7 Medicine Schedule (Poisons Standard)

S4 (Prescription Only Medicine).

Summary Table of Changes