Zorikos is allopurinol, supplied as 100 mg and 300 mg tablets. It is taken every day to prevent gout attacks by lowering uric acid in the blood. It does not treat an attack that has already started — and starting it during one can make things worse.
What is Zorikos?
Zorikos contains allopurinol. The South African Medicine Price Registry lists two strengths, both Schedule 3:
| Product | Form | Strength |
|---|---|---|
| Zorikos 100 | Tablet | Allopurinol 100 mg |
| Zorikos 300 | Tablet | Allopurinol 300 mg |
Gout is caused by uric acid, a waste product of the breakdown of purines — substances found in the body’s own cells and in food. When uric acid levels in the blood stay high, it crystallises in joints. Those needle-shaped crystals provoke intense inflammation, which is the excruciating pain of a gout attack.
Allopurinol blocks xanthine oxidase, the enzyme that produces uric acid. Less uric acid is made, blood levels fall, and over months the crystal deposits already in the joints slowly dissolve.
The two strengths exist because allopurinol is built up gradually — typically starting at 100 mg and increasing every few weeks until blood uric acid reaches a target level. Your dose is set by blood tests, not by how you feel. Someone whose dose is increased is not getting worse; the target simply has not been reached yet.
What is Zorikos commonly used for?
- Preventing gout attacks — the main use. Taken daily and long term, it stops attacks recurring.
- Chronic gouty arthritis, where repeated attacks have caused ongoing joint damage.
- Tophi — the visible lumps of uric acid crystals that form under the skin around joints, ears and fingers in long-standing gout. These shrink and can disappear on sustained treatment.
- Uric acid kidney stones, and preventing their recurrence.
- Preventing tumour lysis syndrome — the surge of uric acid when cancer cells break down rapidly at the start of chemotherapy.
- Certain rare enzyme disorders causing high uric acid.
Three points matter more than the list.
It is a preventer, not a painkiller. During an acute attack, the pain is treated with an anti-inflammatory, colchicine or a steroid. Allopurinol does nothing for the pain of an attack in progress.
Do not start it during an attack. A sudden change in uric acid levels can shake crystals loose and trigger a worse flare. Allopurinol is usually started once an attack has settled.
Attacks can get more frequent at first. In the early months of treatment, as deposits begin to dissolve, flares often increase. This is expected, and it is the single most common reason people abandon a treatment that was working. Doctors frequently prescribe a low-dose anti-inflammatory or colchicine alongside for the first months to cover this period. Do not stop allopurinol because you have an attack on it — stopping and restarting is itself a trigger.
It is usually lifelong. Stop it and uric acid rises again within weeks, and the attacks return.
How Zorikos fits into this medicine category
| Group | Examples | Role in gout |
|---|---|---|
| Xanthine oxidase inhibitors | Allopurinol (Zorikos), febuxostat | Long-term prevention by lowering uric acid |
| Colchicine | Colchicine | Acute attacks, and cover while starting allopurinol |
| NSAIDs | Indomethacin, naproxen, diclofenac | Acute attack pain and inflammation |
| Corticosteroids | Prednisone | Acute attacks where NSAIDs are unsuitable |
| Uricosurics | Probenecid | Increase uric acid excretion; alternative approach |
| Simple analgesics | Paracetamol (Donapan) | Limited help in gout — little anti-inflammatory effect |
Gout treatment splits cleanly into two jobs: putting out the fire, and stopping it starting. Allopurinol only does the second. See the pain, inflammation and musculoskeletal medicines hub.
What to check before using Zorikos
Tell your doctor or pharmacist if you:
- Have kidney disease. This is the most important check. Allopurinol is cleared by the kidneys, the dose usually needs reducing, and reduced kidney function raises the risk of serious reactions.
- Have liver disease.
- Take azathioprine or mercaptopurine. This combination is dangerous — allopurinol blocks their breakdown and levels can rise to toxic. Doses must be drastically reduced, or another approach used.
- Take warfarin, ciclosporin, theophylline, or ACE inhibitors or diuretics for blood pressure.
- Take ampicillin or amoxicillin — rash is more likely in combination.
- Are of Han Chinese, Thai or Korean ancestry, or have kidney disease. These groups carry a higher risk of severe skin reactions, and testing for the HLA-B*5801 gene is sometimes advised beforehand.
- Are pregnant or breastfeeding.
- Are having chemotherapy.
Practical points:
- Take it after food, at the same time each day, to reduce stomach upset.
- Drink plenty of fluid — around two litres daily unless your doctor has restricted it — which helps prevent uric acid crystallising in the kidneys.
- Keep your blood tests. The dose is guided by uric acid levels, and kidney and liver function are monitored too.
- Take it every day, indefinitely, including during an attack once you are established on it.
Diet still matters, though less than most people expect. Reducing alcohol — beer especially — sugary drinks, red meat and shellfish helps; but for most people with recurrent gout, diet alone will not control uric acid, and treating gout as a discipline problem rather than a metabolic one is why so many people suffer with it for years.
Possible cautions and when to ask a pharmacist or doctor
Common effects are rash, nausea, stomach upset, diarrhoea, headache and drowsiness, and — as above — an increase in gout flares during the first months.
Stop taking it and get emergency help immediately for any rash. This is the one warning to remember. Allopurinol can rarely cause severe hypersensitivity reactions, including Stevens-Johnson syndrome and DRESS — conditions that begin as a rash and can be life-threatening. Warning signs:
- Any new rash, particularly if spreading
- Blistering or peeling skin, or sores in the mouth, eyes or genitals
- Rash with fever, swollen glands or facial swelling
- Yellowing of the skin or eyes
Most rashes on allopurinol turn out to be minor. But because the serious ones start the same way, the safe response is always to stop and be assessed, not to wait and see.
Also seek advice for unexplained fever, unusual tiredness or bruising, breathlessness, or a marked drop in urine output.
Contact your doctor if attacks continue after six to twelve months of treatment, if you have stopped taking it for any reason, or if another doctor prescribes you a new medicine — allopurinol has more interactions than its simple appearance suggests.
Related medicine guides
- Browse Pain, Inflammation & Musculoskeletal Medicines guides
- Read: Prednisone used for
- Read: Donapan used for
Frequently asked questions
What is Zorikos used for? Preventing gout attacks by lowering uric acid in the blood. It is also used for uric acid kidney stones and to prevent uric acid surges during chemotherapy. It contains allopurinol.
What is the difference between Zorikos 100 and 300? Only the amount of allopurinol. Treatment usually starts at 100 mg and is increased until blood uric acid reaches target.
Can I take it during a gout attack? If you are already established on it, yes — keep taking it. Do not start it during an attack, as that can worsen the flare.
Will it stop the pain? No. It prevents future attacks. Acute pain is treated with an anti-inflammatory, colchicine or a steroid.
Why am I getting more attacks since starting it? This is expected in the first months, as existing crystal deposits dissolve. It is not a sign of failure. Your doctor may add cover for that period.
How long do I take it for? Usually indefinitely. Uric acid rises again within weeks of stopping and attacks return.
What should I do if I develop a rash? Stop taking it and seek medical attention the same day. Most rashes are minor, but serious skin reactions begin the same way.
Does diet still matter? It helps — less alcohol, fewer sugary drinks, less red meat and shellfish — but for most people with recurrent gout, diet alone will not control uric acid.