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Generic Name: diazepam
Product Name: Antenex

Indication: What Antenex is used for

Antenex is used to manage anxiety, to relieve symptoms associated with alcohol withdrawal such as acute agitation and tremor, and to relax muscles.

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

In general, benzodiazepines such as Antenex should be taken for short periods only (for example 2 to 4 weeks). Continuous long-term use is not recommended unless advised by your doctor. The use of benzodiazepines may lead to dependence on the medicine.

Anxiety and tension associated with the normal stress of everyday life usually do not require treatment with medicines.

Antenex is not recommended for use in children under 6 months of age.

It is available only with a doctor’s prescription.

Action: How Antenex works

Antenex contains the active ingredient diazepam, which belongs to a group of medicines called benzodiazepines. These medicines are thought to work by their action on brain chemicals.

Diazepam exhibits anxiolytic, sedative, muscle relaxant and anticonvulsant effects. This is presumed to be the result of facilitating the action in the brain of gamma-aminobutyric acid, a naturally occurring inhibitory transmitter.

Each Antenex 2 tablet contains 2 mg of diazepam. Each Antenex 5 tablet contains 5 mg of diazepam.

The tablets also contain the following inactive ingredients: lactose, maize starch, magnesium stearate, pregelatinised maize starch (Antenex 2 only), quinoline yellow CI47005 (E104) (Antenex 5 only).

The tablets are gluten free.

Dose advice: How to use Antenex

Before you take Antenex

When you must not take it

Do not take Antenex if you are allergic to:

  • Diazepam or any other benzodiazepine medicine;
  • Any of the ingredients listed here.

Some of the symptoms of an allergic reaction may include skin rash, itching or hives; swelling of the face, lips or tongue, which may cause difficulty in swallowing or breathing; wheezing or shortness of breath.

Do not take Antenex if you have:

  • Severe and chronic lung or airways disease;
  • Severe liver disease;
  • Sleep apnoea;
  • Drug or alcohol dependence.

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 are allergic to any other medicines, foods, dyes or preservatives.

Tell your doctor if you are pregnant or plan to become pregnant. It is not known whether Antenex is harmful to an unborn baby when taken by a pregnant woman. Your doctor will discuss the risks and benefits of taking Antenex if there is a need for you to take Antenex during pregnancy.

Tell your doctor if you are breastfeeding or plan to breastfeed. Antenex is not recommended for use in breastfeeding. Antenex may pass into breast milk and may cause drowsiness and/or feeding difficulties in your baby.

Tell your doctor if you have or have had any of the following medical conditions:

  • Epilepsy, fits or convulsions;
  • Lung, liver or kidney problems;
  • High or low blood pressure;
  • Depression, schizophrenia or other mental illness;
  • Glaucoma (increased pressure in the eye).

Tell your doctor if you drink alcohol regularly. Alcohol may increase the effects of Antenex.

Tell your doctor if you plan to have surgery.

If you have not told your doctor about any of the above, tell them before you start taking Antenex.

Taking other medicines

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

Some medicines may be affected by Antenex, or may affect how well it works. These include:

  • Other sleeping tablets, sedatives or tranquillisers;
  • Medicines for depression;
  • Other medicines for anxiety;
  • Medicines used to treat epilepsy, fits or convulsions (e.g. phenytoin);
  • Antihistamines, medicines for allergies, hayfever, colds or travel sickness;
  • Muscle relaxants;
  • Cimetidine and omeprazole, medicines used to treat reflux or stomach ulcers;
  • Pain relievers;
  • Disulfiram, a medicine used to deter alcohol consumption;
  • Cisapride, a medicine used to treat gastric reflux;
  • Ketoconazole, a medicine used to treat fungal infections.

Your doctor can tell you what to do if you are taking any of these medicines. If you are not sure whether you are taking any of these medicines, check with your doctor or pharmacist.

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

How to take Antenex

Follow all directions given to you by your doctor or pharmacist carefully. They may differ from the information contained here.

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

How much to take

The dose varies from person to person. This depends on your age, the condition being treated, and whether or not you are taking any other medicines.

Your doctor will tell you how many tablets you need to take each day and when to take them. The usual adult dose is between 5 mg and 40 mg daily.

Elderly people, children and those with kidney or liver problems may need smaller doses. Antenex is not recommended for children under 6 months of age.

How to take it

Swallow the tablets with a glass of water.

Antenex can be taken with or without food.

How long to take it for

Take Antenex only for as long as your doctor recommends.

Usually, Antenex should be taken for short periods only (for example 2 to 4 weeks). Continuous long-term use is not recommended unless advised by your doctor. The use of benzodiazepines may lead to dependence on the medicine.

If you forget to take it

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

Otherwise, take the missed dose as soon as you remember, and then go back to taking your tablets 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 take too much (overdose)

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

If you take too much Antenex, you may feel drowsy, tired, confused, dizzy, have difficulty breathing, feel weak or become unconscious.

While you are taking Antenex

Things you must do

Take Antenex exactly as your doctor prescribed.

Before starting any new medicine, tell your doctor or pharmacist that you are taking Antenex. Tell all the doctors, dentists and pharmacists who are treating you that you are taking Antenex.

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

If you plan to have surgery that requires a general anaesthetic, tell your doctor or dentist that you are taking Antenex.

If you have a thyroid function test, tell your doctor that you are taking Antenex. Antenex may affect the results of this test.

Visit your doctor regularly so they can check on your progress.

You may need to have tests to check your blood and liver function. Also, your doctor can advise you on whether you need to keep taking Antenex.

Tell your doctor if you feel Antenex is not helping your condition.

Tell your doctor of any problems or difficulties during or after taking Antenex.

Tell your doctor if, for any reason, you have not taken your medicine exactly as prescribed. Otherwise, your doctor may think that it was not effective and change your treatment unnecessarily.

Things you must not do

Do not stop taking Antenex, or change the dose, without checking with your doctor. Stopping Antenex suddenly may cause some unwanted effects. Your doctor may want you to gradually reduce the amount of Antenex you are taking before stopping completely.

Do not drive or operate machinery until you know how Antenex affects you. Antenex may cause drowsiness, dizziness or loss of concentration in some people. If any of these occur, do not drive, operate machinery or do anything else that could be dangerous. Children should be careful when riding bicycles or climbing trees.

Do not suddenly stop taking Antenex if you suffer from epilepsy. Stopping this medicine suddenly may make your epilepsy worse.

Do not take Antenex for a longer time than your doctor has prescribed. Antenex should be taken for short periods only (for example 2 to 4 weeks) unless advised otherwise by your doctor.

Do not use Antenex to treat any other conditions unless your doctor tells you to.

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

Things to be careful of

Be careful drinking alcohol while taking Antenex. Combining alcohol with Antenex can make you more drowsy or dizzy. Your doctor may suggest that you avoid alcohol or reduce the amount of alcohol that you drink while you are taking Antenex.

Be careful if you are elderly, unwell or taking other medicines. You may have an increased chance of getting side effects such as drowsiness, confusion, dizziness, and unsteadiness, which may increase the risk of a fall.

After taking Antenex


Keep Antenex 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.

Keep your tablets in a cool dry place where the temperature stays below 30°C. Do not store Antenex or any other medicine in the bathroom or near a sink. Do not leave Antenex in the car or on window sills. Heat and dampness can destroy some medicines.


If your doctor tells you to stop taking Antenex, or your tablets have passed their expiry date, ask your pharmacist what to do with any that are left over.

Schedule of Antenex

Antenex is an S4 – prescription only medicine.

Side effects of Antenex

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking Antenex. Antenex helps most people, 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 treatment if you get some of the side effects.

Do not be alarmed by this list of possible side effects. You may not experience any of them.

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

Some people, such as children and the elderly, may have an increased chance of getting some side effects.

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

  • Drowsiness, tiredness;
  • Dizziness, unsteadiness;
  • Loss of memory, inattentiveness, confusion, lack of concentration;
  • Headache, hangover feeling in the morning;
  • Slurred speech;
  • Unpleasant dreams.

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

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

Tell your doctor if you notice anything that is making you feel unwell. Other side effects not listed above may also occur in some people.

For further information talk to your doctor.


  1. Antenex Consumer Medicine Information (CMI). Millers Point, NSW: Alphapharm Pty Ltd. October 2012. [PDF]
  2. Antenex Product Information (PI). Millers Point, NSW: Alphapharm Pty Ltd. April 2013. [PDF]

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Posted On: 22 July, 2003
Modified On: 13 March, 2018
Reviewed On: 13 March, 2018

Created by: myVMC