Paroxib

Indications

Parecoxib is an injectable pain reliever used for the short-term treatment of moderate to severe pain after surgery in adults. It is used in hospital when tablets cannot be taken, often to reduce the need for opioid painkillers in the first days after an operation.

How It Works

Parecoxib is a prodrug: after injection, the body quickly turns it into Valdecoxib, the active form. Valdecoxib selectively blocks an enzyme called COX-2 (cyclo-oxygenase 2), which makes prostaglandins, chemicals that cause pain, swelling and inflammation at the site of injury. Because it acts mainly on COX-2, it has less effect on the protective lining of the stomach and on blood clotting than older anti-inflammatory medicines.

Dosage and Administration

Parecoxib is given by a doctor or nurse as an injection into a vein or deep into a muscle. The dose and how often it is given are decided by the doctor, usually for no more than a few days, with a lower maximum daily dose in older or lighter patients and in people with liver problems. Treatment is switched to tablets as soon as possible.

Interactions

• Blood thinners such as Warfarin can raise the risk of bleeding.
• Aspirin and other NSAIDs increase the risk of stomach ulcers and bleeding.
• It may reduce the effect of blood pressure medicines such as ACE inhibitors, angiotensin receptor blockers and diuretics, and together these can harm the kidneys.
• Ciclosporin and Tacrolimus with Parecoxib can increase kidney damage.
• Fluconazole can raise its levels; Lithium and Methotrexate levels may rise when given with it.

Contraindications

• Allergy to Parecoxib, Valdecoxib or sulfonamide medicines.
• History of asthma, hives, nasal polyps or severe allergic reaction after Aspirin or other NSAIDs.
• Pain after heart bypass surgery (CABG).
• Heart failure, ischaemic heart disease, stroke or serious circulation disease.
• Active stomach ulcer or bleeding, inflammatory bowel disease.
• Severe liver disease, last three months of pregnancy, and breastfeeding.

Side Effects

Common side effects include nausea, stomach pain, indigestion, back pain, high or low blood pressure, swelling of the ankles, itching, low potassium, sleep problems and dry socket after tooth removal. Less often it can cause raised liver enzymes, kidney problems, stomach bleeding, heart attack or stroke. Serious skin reactions are rare.

Get urgent medical help if there is chest pain, sudden weakness on one side of the body or trouble speaking, black or bloody stools or vomiting blood, swelling of the face or throat, difficulty breathing, a spreading rash with blistering or peeling skin, or very little urine.

Pregnancy and Lactation

Parecoxib must not be used in the last three months of pregnancy, as it can harm the baby's heart and kidneys and affect labour. It is generally avoided at other times in pregnancy unless the doctor decides it is clearly needed. It should not be used while breastfeeding; women who need it should stop breastfeeding as advised.

Precautions and Warnings

• It is used at the lowest dose for the shortest possible time.
• Extra care is needed in older people, people with high blood pressure, kidney or liver problems, fluid retention or a history of stomach ulcers.
• It may hide the signs of an infection such as fever.
• Patients are monitored for blood pressure, kidney function and bleeding while receiving it.

Overdose

Because it is given in hospital, overdose is unlikely. Too much may cause stomach upset, drowsiness, kidney problems or bleeding. Treatment is supportive and given by the medical team.

Therapeutic Class

Non-steroidal anti-inflammatory drug (NSAID), selective COX-2 inhibitor.

Storage

Store below 30°C, away from light and out of the reach of children. Once mixed, it is used as directed on the pack.