Family doctor

Brand: Celebrex, contains celecoxib

Use: Anti-inflammatory

Celebrex is used to reduce pain and inflammation due to osteoarthritis or rheumatoid arthritis.

Anti-inflammatories have been available for 30 years or more, and may sometimes cause stomach irritation and less commonly stomach ulcers. Recently, new anti-inflammatories have been developed that are less irritating to the stomach. These are called COX 2 inhibitors. Celebrex is the first COX 2 inhibitor to be available on prescription.

The name COX 2 inhibitor refers to the way that Celebrex works. The original anti-inflammatories such as indomethacin (Indocid), diclofenac (Voltaren, Voltarol), and ibuprofen (Brufen) work on the COX enzymes (1 and 2) to help reduce inflammation and pain. The new anti-inflammatories such as celecoxib works on the COX 2 form of the enzyme rather than COX 1 form. The COX 1 form affects the stomach, so an anti-inflammatory that works on COX 2 is less likely to cause stomach upset and stomach ulcers. Because Celebrex is only fairly new on the market long-term side effects on the stomach are not known for certain yet.

The COX enzyme is needed to form prostaglandins (pros-tar-glan-dins) and it is the prostaglandins that cause pain and inflammation. Stopping the COX enzyme means that less prostaglandins are produced and this reduces pain and inflammation.

The usual dose for osteoarthritis is 200mg once a day or 100mg twice a day. Sometimes it can be increased to 200mg twice a day. For rheumatoid arthritis, the usual dose is 100mg to 200mg twice a day. This medicine doesn't need to be taken with food, but should be taken with a glass of water.

Cautions:

Do not use if:

• You know you are allergic to any ingredient in this medicine.
• You are allergic to sulphonamides (e.g. co-trimoxazole, an antibiotic).
• You are allergic to anti-inflammatories (NSAIDs) or aspirin, including getting a skin rash, itchy skin, swelling of the face, mouth or throat, or worsening of breathing if you take these medicines.
• You are already taking an anti-inflammatory - Celebrex should not be used with another anti-inflammatory. However, taking low dose aspirin for prevention of heart disease can be taken with Celebrex although this might increase the risk of gastric bleeding . (check with your doctor whether to stop aspirin)

Be careful about using Celebrex if you:

• Have had a stomach ulcer or bleeding of the gastro-intestinal tract.
• Have asthma - many asthmatics can use anti-inflammatories without problems but a small proportion can react to these medicines. You may be more likely to react if you have asthma and frequent runny nose symptoms (rhinitis) or have nasal polyps.
• Have kidney or liver problems.
• Have heart failure, fluid retention or high blood pressure.
• Are taking diuretics or ACE inhibitors.
• Are elderly.
• Are dehydrated.
• Have heart disease or other vascular disease(eg history of stroke)  risk factors
• Recent research has shown a slightly increased risk of vascular events (heart attack/ stroke) related to this drug.The effect increases with duration and presence of risk factors .This effect may be similar for many anti-inflammatory drugs and it is important to discuss this risk with your doctor.

As there is no information about celecoxib in pregnancy, breastfeeding, or in children, it is not recommended for use in these situations.

Side effects:

In clinical studies 7.1% of patients stopped taking celecoxib due to side effects - this is compared to 6.1% of those taking pretend or sugar tablets (placebo).

Side effects have included:

• Indigestion
• Abdominal pain
• Allergy
• Headache
• Diarrhoea
• Skin rash
• Worsening of asthma
• Rarely, stomach ulcer or gastro-intestinal bleeding may happen - check with your doctor if you have any discomfort, blood or black flecks in the stools, or if you have any other symptoms that you do not usually have.
• Increased risk of vascular events –heart attack /stroke

There may be other side effects, so if you have any unexpected symptoms while taking this medicine, tell your doctor or pharmacist.

Interactions:

Possible interactions can include:

• ACE inhibitors e.g. enalapril (Renitec), captopril (Capoten), cilazapril (Inhibace), lisinopril (Prinivil)
• Ketoconazole (Nizoral)
• Methotrexate (Ledertrexate, Methoblastin)
• Antacids/indigestion remedies
• Fluconazole (Diflucan)
• Warfarin (Marevan)
• Diuretics e.g. frusemide
• Lithium
• Phenytoin
• Diabetes tablets
• Steroid tablets
• Other anti-inflammatories, including aspirin should not be taken at the same time as Celebrex. This excludes low dose aspirin (e.g. 100mg daily) which can be used with Celebrex.

Patient information:

• Follow the instructions on the label of the medicine or as directed by your doctor.
• Talk to your doctor if think you may possibly have a side effect.
• Can be taken with or without food, and take with a glass of water.
• In New Zealand this medicine is not subsidised by the government and patients have to pay the full cost.
• If you are dehydrated, e.g. from diarrhoea or vomiting, or from endurance exercise, talk to your doctor before taking this medicine.