Allopurinol

Allopurinol

Allopurinol is a powerful drug that doctors often prescribe to help manage gout and high uric acid levels. This medicine works by lowering the amount of uric acid in the body and has revolutionized the way how people deal with gout attacks and kidney stones. Allopurinol has an impact on the way the body makes uric acid, making it a key player in treating these painful conditions.

This article will dive into what allopurinol is and how it works. We will look at various allopurinol tablet uses, the right way to take it, and possible side effects to watch out for. Readers will also learn about the usual allopurinol dose and how to take it safely. 

What is Allopurinol?

Allopurinol is a powerful medication that belongs to a drug category called xanthine oxidase inhibitors. It affects the body's production of uric acid, which can cause gout and kidney stones when levels are too high. It works by lowering the amount of urate in the blood, which is why it is sometimes called a urate-lowering therapy (ULT). 

Allopurinol Tablet Uses

Allopurinol significantly impacts managing various conditions related to high uric acid levels, including: 

• Doctors often prescribe allopurinol 100mg for the long-term treatment & prevention of gout, a type of arthritis where uric acid build-up occurs in the joints, causing sudden attacks of pain and swelling. Allopurinol can prevent gout attacks from happening and help prevent joint damage when taken regularly. 
• This medicine is also helpful to treat high uric acid levels in individuals with certain cancers undergoing chemotherapy. 
• Doctors prescribe allopurinol to manage recurring kidney stones in people with high uric acid levels in their urine. 

How to Use Allopurinol Tablets

• Allopurinol is taken as a tablet once daily, preferably after a meal, to reduce stomach irritation. 
• Swallow the tablet with water and aim to take it at the same time each day. 
• Drinking plenty of water throughout the day is crucial, as this helps your body get rid of more urate through your kidneys. 
• Doctors will monitor your urate levels with blood tests every 2-4 weeks and may adjust your dose accordingly. 
• Remember that allopurinol does not treat immediate gout pain but is a long-term solution to manage urate levels. 
• You should continue taking allopurinol even if you experience more gout attacks initially or if it does not seem to help right away. Your doctor may recommend additional medicines to manage gout attacks during the first few months of treatment.
• Store allopurinol tablets in a closed box at room temperature.

Side Effects of Allopurinol Tablet

Allopurinol can cause side effects, although many people experience no or only minor side effects. Common side effects include: 

• Feeling or being sick
• Diarrhoea
• Skin rashes
• During the first few months of urate-lowering therapy, acute gouty flares are more likely to occur because of the destabilisation of intra-articular uric acid microtophi.

Serious adverse effects can be rare and may include: 

• Liver problems like yellowing of the skin or eyes, dark-coloured urine, light-coloured stool, itching, or unusual tiredness
• Blood disorders
• Kidney problems, like low urine output, unusual tiredness, and swelling in the feet, ankles, or legs
• Severe allergic reactions, like fever, swollen lymph nodes, throat tightness, breathing difficulty, or swelling in the face, eyes, lips, mouth, tongue, or throat
• Stevens-Johnson syndrome (rare), which causes flu-like symptoms followed by a blistering rash 
• Toxic epidermal necrolysis (TEN), which causes painful red rash or blisters on the skin, mouth, nose & genitals

Precautions

• Medication History: Before taking allopurinol, inform your doctor about any allergies to this medication or other drugs, along with all ongoing medicines, vitamins, and herbal supplements. 
• Medical Conditions: Individuals should tell their doctor if they have liver disease, kidney problems, blood disorders, or thyroid issues. 
• Ethnicity: People of Han Chinese, Thai, or Korean origin are more prone to serious side effects of this drug.
• Lactation: Allopurinol can pass through milk, so breastfeeding women should inform their doctor.
• Dizziness: Allopurinol can cause dizziness or drowsiness, so avoid driving a vehicle if you experience these effects. 
• Gout Flare-up: Starting allopurinol might trigger a gout attack initially, but it is important to continue taking the medicine as prescribed. Your doctor may give you additional medication to reduce the risk of these attacks. 

How Allopurinol Tablet Works

Allopurinol impacts the body's production of uric acid by inhibiting an enzyme called xanthine oxidase. This enzyme is a key component in converting hypoxanthine to xanthine & then to uric acid. By stopping this process, allopurinol lowers the amount of urate in the blood, which is why it is sometimes called a urate-lowering therapy (ULT). When urate levels drop, new crystals stop forming, and existing crystals slowly dissolve. This process can take a few years, during which you might still experience gout attacks. However, once all the crystals dissolve, there will be no further joint damage or gout attacks due to these crystals as long as you keep taking allopurinol. It is important to note that allopurinol does not treat immediate gout pain but is a long-term solution to manage urate levels.

Can I Take Allopurinol with Other Medicines?

Allopurinol can interact with several medications, such as:

• ACE inhibitors
• Amoxicillin
• Ampicillin
• Aspirin
• Azathioprine
• Cancer medicines
• Cyclosporine
• Furosemide
• Penicillin antibiotics 
• Probenecid
• Theophylline
• Thiazide diuretics 
• Warfarin

Dosing Information

The starting dose of allopurinol for gout treatment is 100 mg daily. Doctors gradually increase this by 100 milligrams every two to five weeks until the target serum uric acid level is reached. 

For patients with kidney problems, the starting dose is lower at 50 mg daily, increased by 50 mg every 2 to 5 weeks. 

To prevent tumour lysis syndrome, the initial dose of allopurinol is 2 to 3 days before chemotherapy and continues for 3 to 7 days after. The dose for this use is 300 mg/m² daily in three divided doses, up to 800 mg daily.

FAQs

1. What happens if I miss a dose?

If you forget to take allopurinol, take it as soon as you remember unless it is almost time for your next scheduled dose. In that situation, skip the missed one and take your next dose at the usual time. 

2. What happens if I overdose?

If you take more than your prescribed dose of allopurinol and experience symptoms like nausea, vomiting, diarrhoea, dizziness, tiredness, headaches, or stomach pain, seek medical advice immediately. Go to A&E if necessary and bring the allopurinol packet, any remaining medicine, and any other medicines you take.

3. What to avoid when taking allopurinol?

Avoid drinking alcohol excessively while taking allopurinol, as it can increase urate levels in the blood and trigger gout attacks. Be cautious when driving a vehicle, as allopurinol may cause drowsiness or dizziness in some people. Discuss any new medications with your treating doctor before starting them, as allopurinol can interact with certain drugs.

4. Is allopurinol safe?

Allopurinol is generally safe when taken as prescribed. However, it can cause side effects in some people. Common side effects include rashes, headaches, drowsiness, dizziness, nausea, and changes in taste. Always follow your clinician's instructions and report any concerning symptoms immediately.

5. What is the allopurinol drug commonly used for?

Allopurinol is primarily used for the long-term treatment and prevention of gout. It works by lowering urate levels in the blood, which helps stop gout attacks and prevent joint damage. It is also used to manage high uric acid levels in certain types of cancer patients undergoing chemotherapy and to prevent recurring kidney stones in individuals with high uric acid urine levels.

6. Who cannot take allopurinol?

Allopurinol may not be suitable for everyone. People who have had an allergic reaction to allopurinol before should not take it. Those of Han Chinese, Thai, or Korean origin may need genetic testing before starting allopurinol due to a higher possibility of severe side effects. Patients with liver or kidney problems may need dose adjustments. 

7. Why is allopurinol taken at night?

There is no specific recommendation to take allopurinol at night. It is taken once daily, and the time of day does not significantly affect its effectiveness. However, some people may find it convenient to take it at night as part of their bedtime routine. The most important thing is to take it consistently at the same time each day.

8. Can I take allopurinol every other day?

Doctors usually prescribe allopurinol to be taken daily. Taking it every other day may not maintain consistent uric acid levels in your blood, which could reduce its effectiveness in preventing gout attacks. Always follow your doctor's instructions regarding allopurinol dosage and frequency. 

9. Is allopurinol harmful to the kidneys?

Contrary to common belief, allopurinol is not harmful to the kidneys. Studies have shown that allopurinol may help slow the advancement of kidney disease in some patients. It can be used safely in patients with kidney problems, although the dose may need to be adjusted. 

10. Are colchicine and allopurinol the same?

No, colchicine and allopurinol are different medications used to treat gout. Colchicine helps treat acute gout attacks and reduce inflammation. On the other hand, allopurinol is a long-term treatment that lowers uric acid levels to prevent gout attacks. They work differently and are often used at different stages of gout management.

11. When to stop allopurinol?

Allopurinol is usually a long-term treatment; you should not stop taking it without consulting your doctor. Suddenly, stopping allopurinol can trigger gout attacks. Only stop taking allopurinol if your doctor advises you to do so.