Pyrazone

Indications

Sulfinpyrazone is used for the long-term treatment of chronic gout and high uric acid levels in the blood (hyperuricaemia). Taken regularly, it helps prevent new gout attacks and can slowly shrink tophi, the chalky lumps of uric acid crystals that form under the skin. It does not relieve a gout attack that has already started.

How It Works

Uric acid is removed from the body mainly by the kidneys. Sulfinpyrazone is a uricosuric medicine: it stops the kidneys from taking uric acid back into the blood, so more is passed out in the urine. As blood uric acid falls, fewer crystals form in the joints. It also has a mild effect on blood platelets, making them less sticky.

Dosage and Administration

The dose is as prescribed. Treatment is usually started at a low dose and increased gradually over a few weeks, then reduced to the lowest dose that keeps uric acid under control. Take the tablets with food or milk to reduce stomach upset. Drink plenty of water, at least 2 litres a day unless your doctor says otherwise, to help prevent kidney stones. Do not start it during an acute attack; your doctor may give Colchicine or a pain reliever for the first months to prevent flares.

Interactions

• Aspirin and other salicylates: block the effect of Sulfinpyrazone and should be avoided.
• Warfarin and other blood thinners: bleeding risk may increase.
• Sulfonylureas for diabetes such as Glibenclamide: blood sugar may fall too low.
• Phenytoin and Theophylline: blood levels may change.
• Penicillins and some other medicines removed by the kidneys: their levels may rise.

Contraindications

Do not take Sulfinpyrazone if you are allergic to it or to similar medicines, have an active stomach or duodenal ulcer, have severe kidney or liver disease, have a blood disorder, have porphyria, or have kidney stones made of uric acid. It should not be used during an acute gout attack.

Side Effects

Common side effects include stomach pain, nausea, indigestion and, at the start of treatment, more frequent gout attacks. Rash, fluid retention and kidney stones can occur. Rarely, it may affect the blood counts or the kidneys.

Get urgent medical help if you have black or bloody stools, vomiting blood, severe stomach pain, blood in the urine or severe pain in the side or back, a sudden drop in urine, unusual bleeding or bruising, sore throat with fever, or a severe skin reaction.

Pregnancy and Lactation

There is limited information on use in pregnancy, so it should be used only if your doctor feels it is clearly needed. It is not known whether it passes into breast milk; ask your doctor before breastfeeding.

Precautions and Warnings

Your doctor may check blood counts and kidney function from time to time. Use with care if you have a history of stomach ulcers, kidney problems or heart failure. Keep drinking plenty of fluids. Avoid taking Aspirin for pain; ask your pharmacist for a suitable alternative.

Overdose

An overdose may cause nausea, vomiting, stomach pain, difficulty breathing, unsteadiness and fits. Seek medical help straight away.

Therapeutic Class

Uricosuric agent (anti-gout medicine).

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.