Allopurinol (Zyloprim, Aloprim) is a xanthine oxidase inhibitor that prevents attacks of gout and renal stones in affected patients, and also treats some complications of cancer chemotherapy. It works by reducing the amount of a chemical called uric acid, which in high doses is responsible for these conditions. Allopurinol is not used to treat gout or renal stones, rather to prevent further attacks in patients already affected by these conditions.
Allopurinol is taken as a tablet form, and is initially taken once a day, ideally with food. The tablets come in 100g and 300g strengths.
When you start taking allopurinol, your doctor will do regular blood tests for the first few months. These will be to measure your uric acid levels. This is because allopurinol reduces blood uric acid levels, and by measuring this it can be determined whether your treatment needs adjusting. This will allow you to take the optimum amount of medication for you, as taking too much allopurinol if you don’t need to can cause unnecessary side-effects. Depending on the results of the blood tests, you may have to change your dose of allopurinol regularly for the first few weeks, and you may end up having to taking the medication several times a day.
Below are the dosages of allopurinol adjusted for different medical conditions and for different patient age groups.
Dosage of Allopurinol for Gout and Kidney Stones
For Gout in Adults and the Elderly: the starting dose of allopurinol is 100mg. The dose will be adjusted over the course of a few weeks to months, depending on your uric acid levels and whether you suffer any more attacks of gout or renal stones. The end dose will vary from 100mg to 800mg depending on the severity of your condition.
If the dose is over 300mg, it must be divided into two or three doses and taken several times a day.
Dosage of Allopurinol for Cancer- Related Hyperuricaemia
For Adults: 600-800mg daily with a high fluid intake. Lots of fluids are required to ensure the kidneys are well hydrated and can effectively remove the uric acid from the body.
For children: the amount taken will depend on the child’s weight and age but is usually between 150mg-300mg. Lots of fluids will be required (at least eight glasses daily) to remove the uric acid from the body.
What to Remember when Taking Allopurinol
When taking allopurinol, you should follow the advice given to you by your doctor or pharmacist. You should store the medicine in a cool, dark place away from children. You should never share your medication with other people, even if they appear to have the same symptoms as you, because you do not know their medical history and you could cause them harm. If you miss a dose, do not take double the next time. Allopurinol is usually taken life-long.
Allopurinol is a preventative medication, and does not help treat attacks of gout and kidney stones. You should continue to take allopurinol during an attack, but you should also contact your doctor for medication to help you deal with this.