Clonac tablet – Information, specialists, frequent questions.

Usage of Clonac tablet

This leaflet answers some common questions about Clonac

It does not contain all the available information

It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor has weighed the risks of you taking it against the benefits they expect it will 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 need to read it again.

Clonac relieves pain and reduces inflammation (swelling and redness) that may occur in the following:

  • different types of arthritis including rheumatoid arthritis and osteoarthritis
  • other painful conditions where swelling is a problem such as back pain, rheumatism, muscle strains, sprains and tendonitis (eg. tennis elbow)
  • menstrual cramps (period pain)

Clonac belongs to a family of medicines called non-steroidal anti-inflammatory drugs (NSAIDs). These medicines can relieve the symptoms of pain and inflammation but they will not cure your condition.

Your doctor may prescribe Clonac for another purpose.

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

Clonac is only available with a doctor’s prescription. It is not addictive.

Special precautions

When you must not take it

Do not take Clonac if you have an allergy to:

  • diclofenac (the active ingredient in Clonac) or any of the other ingredients listed at the end of this leaflet
  • other medicines containing diclofenac (eg. Voltaren®)
  • aspirin
  • any other NSAID medicine

Many medicines used to treat headache, period pain and other aches and pains contain aspirin or NSAID medicines. If you are not sure if you are taking any of these medicines, ask your pharmacist.

Symptoms of an allergic reaction to these medicines may include:

  • asthma, wheezing or shortness of breath
  • swelling of the face, lips or tongue which may cause difficulty in swallowing or breathing
  • hives, itching or skin rash
  • fainting

If you are allergic to aspirin or NSAID medicines and take Clonac, these symptoms may be severe.

Do not take Clonac if at the present time you have an ulcer (gastric or duodenal) or bleeding from the stomach or bowel. If you take it, your stomach problem may become worse.

Do not take Clonac after the expiry date printed on the pack.

Do not take Clonac if the packaging is torn or shows signs of tampering.

Do not give Clonac to a child. Clonac is not recommended for use in children, as there is not enough information on its use in this age group.

If you are not sure whether you should start taking Clonac, contact your doctor.

Before you start to take it

Tell your doctor if you are allergic to any other medicines, foods, dyes or preservatives. Your doctor will want to know if you are prone to allergies.

Tell your doctor if, in the past, you have ever had:

  • ulcers (gastric or duodenal)
  • severe attacks of indigestion or other stomach trouble
  • diseases of the bowel (eg. Crohn’s disease, ulcerative colitis)

Tell your doctor if you have any of these health problems/medical conditions at the present time:

  • heart disease
  • kidney disease
  • liver disease
  • high blood pressure
  • a tendency to bleed or other blood problems such as anaemia
  • asthma

Your doctor may want to take special precautions if you have any of these conditions.

Tell your doctor if you have an infection at the present time. If you take Clonac while you have an infection, some of the signs of the infection may be hidden (pain, fever, swelling, redness). You may think, mistakenly, that you are better or that the infection is not serious.

Tell your doctor if you are pregnant or are breast-feeding. Like most NSAID medicines, Clonac is not recommended for use during pregnancy or breast-feeding. Your doctor will discuss with you the benefits and risks of taking it.

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 that are important to mention include:

  • aspirin, salicylates, coxibs such as Celebrex® or other NSAID, medicines used to relieve pain and inflammation
  • ACE inhibitors such as Zestril® and Renitec, or angiotensin receptor antagonist such as Cozaar, medicines used to treat high blood pressure
  • diuretics, also called fluid or water tablets
  • warfarin, a medicine used to stop blood clots
  • digoxin, a medicine for your heart
  • lithium, a medicine used to treat some types of depression
  • tablets used to treat diabetes
  • methotrexate, a medicine used to treat arthritis and some cancers
  • cyclosporin, a medicine used to suppress the immune system
  • certain antibiotics called quinolones

Your doctor or pharmacist has more information on medicines to be careful with or avoid while taking Clonac.

If you have not told your doctor about any of these things, tell them before you take Clonac.

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

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

How much to take

Clonac comes in 25 mg and 50 mg tablets.

For arthritis or other painful conditions where swelling is a problem

Your doctor may start your treatment with anywhere from 75 mg to 150 mg per day, depending on your situation. After the early stages of treatment it is usually possible to reduce the daily dose to 75 mg to 100 mg per day.

For menstrual cramps (period pain)

At the start of treatment the daily dose is usually between 50 mg and 100 mg. If necessary, it can be raised over several menstrual periods to a maximum of 200 mg each day.

How to take it

Clonac tablets are usually taken in 2 or 3 doses during the day.

Swallow the tablets whole with a full glass of water. Do not chew them. The tablets have a special coating to stop them dissolving until they have passed through the stomach into the bowel. Chewing them would destroy the coating.

They will work more quickly if you take them at least half an hour before meals or two hours after meals. But, if they upset your stomach, you can take them with food.

How long to take it

Do not take Clonac for longer than your doctor says.

If you are taking Clonac for arthritis, it will not cure your disease but it should help to control pain and inflammation. It usually begins to work within a few hours but several weeks may pass before you feel the full effects of the medicine.

For menstrual cramps (period pain), the tablets are usually taken during each period as soon as cramps begin and continued for a few days until the pain goes away.

If you forget to take it

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

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

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

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

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

If you take too much (Overdose)

Immediately telephone your doctor or Poisons Information Centre (telephone 13 11 26), or go to casualty at your nearest hospital if you think that you or anyone else may have taken too much Clonac. Do this even if there are no signs of discomfort or poisoning.

Keep the telephone numbers for these places handy.

Things you must do

If you become pregnant while taking Clonac, tell your doctor immediately. Your doctor can discuss with you the risks of taking it while you are pregnant.

If you are about to be started on any new medicine, tell your doctor and pharmacist that you are taking Clonac.

Be sure to keep all of your doctor’s appointments so that your progress can be checked. Your doctor may want to take some blood tests from time to time. This helps to prevent unwanted side effects.

If you are going to have surgery, make sure the surgeon and anaesthetist know that you are taking Clonac. NSAID medicines can slow down blood clotting.

If you get an infection while taking Clonac, tell your doctor. This medicine may hide some of the signs of an infection (pain, fever, swelling, redness). You may think, mistakenly, that you are better or that the infection is not serious.

Tell all of the doctors, dentists and pharmacists that are treating you that you are taking Clonac.

Things you must not do

Do not take any other medicines used to treat arthritis while you are taking Clonac without first telling your doctor. This includes:

  • aspirin
  • other salicylates
  • other forms of diclofenac (e.g. Voltaren®)
  • any other NSAID medicine

If you take these medicines together with Clonac they may cause unwanted effects.

If you need to take something for headache or fever, it is usually okay to take paracetamol. If you are not sure, ask your doctor.

Do not stop any other forms of treatment for arthritis that your doctor has told you to follow. This medicine does not replace exercise or rest programs or the use of heat/cold treatments.

Do not use Clonac to treat any other complaints unless your doctor says you can.

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

Things to be careful of

Be careful driving, operating machinery or doing jobs that require you to be alert until you know how Clonac affects you. Clonac may cause dizziness, drowsiness or blurred vision in some people. If you have any of these symptoms, do not drive or do anything else that could be dangerous.


  • Keep your medicine in the original container until it is time to take it.
  • Store the container in a cool dry place where the temperature stays below 25°C.
  • Do not store Clonac or any other medicine in the bathroom or any other place that is hot or steamy.
  • Do not leave it in the car or on window sills.

Heat and dampness can destroy some medicines.

Keep the medicine 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 Clonac or you find that it has passed the expiry date, ask your pharmacist what to do with any medicine you have left over.

Adverse and side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking Clonac. This medicine helps most people, but it may have unwanted side effects in a few people. All medicines 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.

If you are over 65 years old, you should be especially careful while taking this medicine. Report any side effects promptly to your doctor. As people grow older, they are more likely to get side effects from medicines.

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.

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

  • stomach upset including nausea (feeling sick), vomiting, heartburn, indigestion, cramps
  • loss of appetite
  • constipation, diarrhoea, pain in the stomach, wind
  • dizziness, light headedness
  • drowsiness, sleepiness, disorientation
  • buzzing or ringing in the ears
  • change in mood, for example, feeling depressed, anxious or irritable
  • trembling, sleeplessness, nightmares
  • headache
  • sore mouth or tongue
  • hair loss or thinning
  • altered taste sensation

Tell your doctor immediately if you notice any of the following:

  • severe pain or tenderness in the stomach
  • signs of frequent or worrying infections such as fever, severe chills, sore throat or mouth ulcers
  • bleeding or bruising more easily than normal; reddish or purplish blotches under the skin
  • signs of anaemia such as tiredness, being short of breath, looking pale
  • a change in the colour of urine passed, blood in the urine
  • a change in the amount or frequency of urine passed, burning feeling when passing urine
  • signs of a liver problem such as tiredness, lack of energy, itching of the skin, yellowing of the skin and eyes, pain in the abdomen
  • unusual weight gain, swelling of ankles or legs
  • symptoms of sunburn (such as redness, itching, swelling, blistering) which may occur more quickly than normal
  • eye problems such as blurred or double vision
  • severe dizziness, spinning sensation
  • severe or persistent headache
  • tingling or numbness of the hands or feet
  • fast or irregular heart beat, also called palpitations
  • difficulty hearing

These are serious side effects. You may need urgent medical attention. Serious side effects are rare.

If any of the following happen, stop taking Clonac and tell your doctor immediately or go to casualty at your nearest hospital:

  • vomiting blood or material that looks like coffee grounds
  • bleeding from the back passage, black sticky bowel motions (stools) or bloody diarrhoea
  • swelling of the face, lips or tongue which may cause difficulty in swallowing or breathing
  • asthma, wheezing, shortness of breath
  • sudden or severe itching, skin rash or hives
  • fainting or seizures (fits)
  • pain or tightness in the chest

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

Tell your doctor if you notice anything else that is making you unwell.

Some people may get other side effects when taking Clonac.

Questions about Clonac tablet

Our experts have answered 11 questions about Clonac tablet

Dr. Joseph Jabbour
Dr. Joseph Jabbour
Gynaecologist, Obstetrics specialist
Hi there,
Clonac is Diclofenac which is a non-steroidal anti inflammatory. You can certainly take this in combination to paracetamol and codeine.
The combination of these medications…
1 answers

Dr. Joseph Jabbour
Dr. Joseph Jabbour
Gynaecologist, Obstetrics specialist
i would advise against alcohol with clonac as alcohol can increase the rate of toxicity and cause worsening of some side effects-Mainly gastrointestinal problems such as gastritis, peptic ulcers,…
1 answers

Dr. Joseph Jabbour
Dr. Joseph Jabbour
Gynaecologist, Obstetrics specialist
Very small amounts of the clonac (diclofenac) is found in the breast milk. We use it after Caesarean sections regularly and we have been doing so for many years (mainly in suppository form).…
1 answers

What professionals prescribe Clonac tablet?

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