Aloric

Indications

Allopurinol is used for long-term prevention of gout attacks and to lower high uric acid levels in the blood. It is also used to prevent some types of kidney stones (uric acid stones, and calcium stones linked to high uric acid), and to prevent a sudden rise in uric acid during some cancer treatments.

How It Works

Allopurinol blocks an enzyme called xanthine oxidase, which the body uses to make uric acid. With less uric acid, crystals stop forming in the joints and kidneys, and existing crystals slowly dissolve.

Dosage and Administration

Adults: usually started at 100 mg once a day. The doctor raises the dose slowly, often by 100 mg every 2 to 4 weeks, based on blood uric acid tests. A common long-term dose is 100 to 300 mg a day; some people need more under a doctor's supervision. Lower doses are used in kidney disease. Take it once a day after food with a glass of water, and drink plenty of fluids (about 2 litres a day). Gout attacks can become more frequent in the first months; keep taking it, and the doctor may give another medicine (such as Colchicine) to prevent flares. It is not started during an attack, but if you already take it, do not stop during an attack. For cancer treatment, use as prescribed.

Interactions

• Azathioprine and Mercaptopurine: Allopurinol greatly increases their levels; their dose must be reduced by the doctor.
• Warfarin: its effect may increase.
• Amoxicillin and Ampicillin: skin rash is more likely.
• Theophylline, Ciclosporin and Chlorpropamide levels can rise.
• Thiazide diuretics and ACE inhibitors (such as Captopril) may increase the risk of allergic reactions, especially with kidney problems.

Contraindications

Allergy to allopurinol, or any previous serious skin reaction to it.

Side Effects

The most common side effect is a skin rash; stop taking it and see a doctor if a rash appears. Others include nausea, stomach upset, diarrhoea, drowsiness, headache and gout flares at the start. Rarely, it causes a severe allergic reaction. Stop taking it and get urgent medical help if you have a rash with blisters, peeling skin, mouth or eye sores, fever, swollen glands, yellow skin or eyes, or swelling of the face or throat.

Pregnancy and Lactation

Not usually used in pregnancy; take it only if a doctor decides the benefit outweighs the risk. It passes into breast milk, so ask your doctor before using it while breastfeeding.

Precautions and Warnings

Tell your doctor if you have kidney or liver disease, heart failure or high blood pressure, or take water tablets. People of some Asian backgrounds (such as Han Chinese, Thai and Korean) have a higher risk of severe skin reactions, and a genetic test (HLA-B*5801) may be done before starting. Blood tests may be needed. It can cause drowsiness, so take care when driving.

Overdose

Overdose may cause nausea, vomiting, diarrhoea and dizziness. Seek medical help; drinking plenty of fluids helps the kidneys remove it.

Therapeutic Class

Anti-gout medicine (xanthine oxidase inhibitor).

Storage

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