Key Takeaways
- Allopurinol lowers urate and prevents future gout; colchicine treats and prevents short-term flare inflammation. They are not interchangeable. [1]
- Allopurinol does not relieve an acute flare, and colchicine does not lower urate. [1]
- Allopurinol is taken daily long-term and started low, then titrated to a serum urate below 6 mg/dL. [1]
- Colchicine for a flare is low-dose (1.2 mg, then 0.6 mg one hour later); for prophylaxis it is taken at a low daily dose. [2][3]
- When urate-lowering therapy starts, short-term colchicine or NSAID prophylaxis reduces early flares. [1][4]
- Allopurinol can rarely cause severe skin reactions, especially with the HLA-B*58:01 allele; colchicine can be toxic with interacting drugs or kidney or liver disease. [5][3]
Two Different Jobs
Gout has two distinct problems: the crystal-driven inflammation of an acute flare, and the chronically high urate that keeps producing those crystals. The medicines map onto those two problems. Allopurinol attacks the underlying driver by lowering urate production; colchicine calms the inflammation of a flare without touching urate.[1]
The one-sentence version: allopurinol is a daily, long-term urate-lowering drug; colchicine is an anti-inflammatory used for flares and for short-term flare prevention. If you want to lower uric acid, you need allopurinol (or a related drug). If you want to stop the pain of this week's attack, you need colchicine, an NSAID, or a steroid.[1]
Allopurinol: What It Does
Allopurinol and its active metabolite oxypurinol block xanthine oxidase, the enzyme that converts hypoxanthine and xanthine into urate. This reduces urate production and, over months, lowers serum urate enough to dissolve existing monosodium urate crystals and stop new flares.[6] Allopurinol is the preferred first-line urate-lowering drug in the 2020 ACR guideline, including for many people with chronic kidney disease.[1]
It is not a flare medicine. It works slowly over weeks to months, and in fact starting it can trigger a flare in the first months as urate levels shift, which is exactly why short-term colchicine or NSAID prophylaxis is added.[1] Starting low (commonly 100 mg daily, lower with kidney impairment) and titrating against measured serum urate both reduces the risk of flares and of serious skin reactions.[1]
Colchicine: What It Does
Colchicine is 300-year-old anti-inflammatory medicine that reduces the neutrophil-driven and inflammasome-driven inflammation caused by urate crystals.[3] It does not lower serum urate. For an acute flare, the evidence-backed regimen is low-dose: 1.2 mg at the first sign, then 0.6 mg one hour later, which in the AGREE trial matched the older high-dose course for pain relief with far fewer side effects.[2]
Colchicine also serves a second role: low-dose daily prevention. When someone begins urate-lowering therapy, a once- or twice-a-day low dose of colchicine (or an NSAID) for the first several months reduces the flares that often accompany the initial fall in urate.[1]
Can You Take Allopurinol and Colchicine Together?
Yes, and this combination is standard practice. A person starting allopurinol often takes low-dose colchicine (or an NSAID) at the same time as flare prophylaxis, then stops the prophylaxis after several months once urate is stable at target. This is not taking two gout drugs for the same job. It is pairing a urate-lowering drug with an anti-inflammatory.[1]
The details are being refined. A 2023 non-inferiority trial found that with the start-low, go-slow allopurinol escalation strategy, routine colchicine prophylaxis did not clearly reduce flares over the first six months for many patients, suggesting some people can skip it, but clinical practice still commonly uses short-term prophylaxis, especially for people at higher flare risk.[4]
Which One, When
| Question | Answer |
|---|---|
| Which stops the pain of a flare happening right now? | Colchicine, an NSAID, or a corticosteroid, not allopurinol. |
| Which prevents gout over years? | Allopurinol (or another urate-lowering drug) titrated to a urate target. |
| Which is started when urate-lowering therapy begins? | Both: allopurinol daily plus short-term colchicine or NSAID prophylaxis. |
| Which lowers uric acid? | Allopurinol only. Colchicine does not affect urate. |
Allopurinol vs Colchicine: Side by Side
| Allopurinol | Colchicine | |
|---|---|---|
| Drug class | Xanthine oxidase inhibitor (lowers urate) | Anti-inflammatory (microtubule and inflammasome effects) |
| Purpose | Long-term gout prevention | Acute flare treatment and short-term prophylaxis |
| How long | Daily, usually lifelong | Short course for a flare; a few months for prophylaxis |
| Effect on urate | Lowers serum urate below target | No effect on urate |
| Effect on a flare | None (may even cause early flares) | Reduces flare pain and inflammation |
Dosing and Titration
Allopurinol is started low, commonly 100 mg daily or less in kidney disease, then increased in steps (for example to 200 mg and then 300 mg) using repeated serum urate measurements until urate is below 6 mg/dL, or below 5 mg/dL in tophaceous disease.[1] The starting dose matters: it reduces the risk of early flares and of the allopurinol hypersensitivity reaction.[1] A fixed 300 mg dose reaches the urate target in only about one in five patients in older trials, which is why titration is important.[7]
Colchicine for a flare is 1.2 mg followed by 0.6 mg one hour later, and patients are counseled on a maximum course and to report diarrhea. For prophylaxis during urate-lowering initiation, a lower once- or twice-a-day maintenance dose is typical, with adjustment for kidney function and interacting drugs.[2][3]
Side Effects and Safety
Allopurinol is usually well tolerated, but it can cause a rash and, rarely, a severe hypersensitivity syndrome or life-threatening skin reactions such as Stevens-Johnson syndrome. The HLA-B*58:01 allele strongly predicts these severe reactions, which is why the guideline conditionally recommends testing before starting allopurinol in people of Southeast Asian or African American ancestry, and why any new widespread rash or blistering means stop the drug and seek care immediately.[5][1]
Colchicine's main dose-limiting effect is gastrointestinal, nausea, vomiting, and diarrhea, and it has a narrow safety margin in overdose. Because it is cleared partly by CYP3A4 and P-glycoprotein, strong inhibitors (clarithromycin, azole antifungals, some HIV medicines, and others) can push levels to toxic ranges, especially with kidney or liver disease, so dose adjustment and an interaction review are essential.[3]
| Safety point | Allopurinol | Colchicine |
|---|---|---|
| Most common issue | Mild rash | Gastrointestinal upset (diarrhea, nausea) |
| Serious concern | Severe skin reactions (SJS, TEN), rare but life-threatening | Toxicity with interacting drugs or kidney or liver disease |
| Predictive marker | HLA-B*58:01 allele | CYP3A4 and P-gp interactions |
| Kidney or liver disease | Start lower and titrate | Requires dose reduction and caution |
Cardiovascular Considerations
These drugs sit differently in the cardiovascular picture. Febuxostat, the other xanthine oxidase inhibitor, carries a U.S. boxed warning for cardiovascular death after the CARES trial, even though the larger FAST trial found noninferiority to allopurinol, so cardiovascular history is reviewed whenever febuxostat is considered; allopurinol remains preferred first-line.[8][9][1] Separately, low-dose colchicine is being studied as a cardiovascular drug in its own right after the COLCOT trial showed benefit after myocardial infarction, but that use is distinct from gout.[10]
Common Mistakes
- Taking allopurinol only during a flare. Allopurinol is a daily preventive medicine; taking it only when a joint hurts does not treat the flare and defeats its purpose.[1]
- Stopping allopurinol during a flare. Continue it; treat the flare separately.[1]
- Using colchicine as a long-term urate treatment. Colchicine does not lower urate, so using it indefinitely instead of allopurinol leaves the crystal burden in place.[1]
- Using old high-dose colchicine. Hourly dosing until diarrhea is obsolete and toxic; low-dose is equivalent for pain and safer.[2]
- Skipping the starting dose step on allopurinol. Starting at a full dose raises flare and skin-reaction risk.[1]
Red Flags
Stop the medicine and seek care for a new widespread rash, blistering, mouth sores, eye irritation, facial swelling, or fever after starting allopurinol (possible severe skin reaction), or for severe diarrhea, vomiting, or muscle weakness with colchicine (possible toxicity).[5][3]
Do not self-adjust either drug based on symptoms. Allopurinol is titrated on measured urate, and colchicine is dose-limited by toxicity and interactions, so both belong in a clinician-guided plan.[1][3]
Frequently Asked Questions
Yes. This is standard when starting urate-lowering therapy: allopurinol is taken daily long-term while a short course of low-dose colchicine (or an NSAID) prevents early flares. A clinician will specify the dosing and duration.[1]
No. Allopurinol lowers urate over weeks to months; it does not relieve an acute flare and can even cause a temporary increase in flares when started. Flare pain needs colchicine, an NSAID, or a steroid.[1]
No. Colchicine reduces inflammation but has no meaningful effect on serum urate. Only urate-lowering drugs such as allopurinol or febuxostat lower urate.[1]
They are not alternatives; they treat different parts of gout. Allopurinol is the long-term urate-lowering drug, and colchicine is an anti-inflammatory for flares and short-term prophylaxis.[1]
Usually long-term, often lifelong, because stopping it lets urate rise again and flares return. The dose is adjusted to keep serum urate below target.[1]
It lowers urate within weeks, but reducing flares and dissolving crystals takes months. That is why urate-lowering therapy is a long-term strategy, not a quick fix.[1]
Commonly 100 mg daily, or lower with kidney disease, then increased in steps using serum urate measurements until urate is below 6 mg/dL. Starting low reduces flares and skin reactions.[1]
Rare but serious skin reactions including Stevens-Johnson syndrome, linked to the HLA-B*58:01 allele. Any new widespread rash, blistering, or fever means stopping the drug and getting urgent care.[5]
Mostly gastrointestinal: nausea, vomiting, and diarrhea. It can be toxic when combined with certain drugs or in kidney or liver disease, so doses must be reviewed.[3]
Allopurinol is preferred first-line for many people with chronic kidney disease, started at a lower dose and titrated carefully with monitoring.[1]
Flare prophylaxis is generally a short-term measure for the first months of urate lowering. Whether and when to stop depends on how long urate has been at target, so confirm with a clinician.[1]
References
- FitzGerald JD, Dalbeth N, Mikuls T, et al. 2020 American College of Rheumatology Guideline for the Management of Gout. Arthritis Care & Research. 2020;72(6):744-760. doi:10.1002/acr.24180. https://pmc.ncbi.nlm.nih.gov/articles/PMC10563586/
- Terkeltaub RA, Furst DE, Bennett K, Kook KA, Crockett RS, Davis MW. High versus low dosing of oral colchicine for early acute gout flare. Arthritis & Rheumatism. 2010;62(4):1060-1068. doi:10.1002/art.27327. PMID: 20131255. https://pubmed.ncbi.nlm.nih.gov/20131255/
- U.S. Food and Drug Administration. COLCRYS (colchicine) prescribing information. Updated 2024. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8a5edd42-f1e5-4a67-a802-e2c0f6d19023
- Stamp L, Horne A, Mihov B, Drake J, Haslett J, et al. Is colchicine prophylaxis required with start-low go-slow allopurinol dose escalation in gout? A non-inferiority randomised double-blind placebo-controlled trial. Annals of the Rheumatic Diseases. 2023;82(12):1626-1634. doi:10.1136/ard-2023-224731. PMID: 37652661. https://pubmed.ncbi.nlm.nih.gov/37652661/
- Hung SI, Chung WH, Liou LB, et al. HLA-B*5801 allele as a genetic marker for severe cutaneous adverse reactions caused by allopurinol. Proceedings of the National Academy of Sciences USA. 2005;102(11):4134-4139. doi:10.1073/pnas.0409500102. PMID: 15743917. https://pubmed.ncbi.nlm.nih.gov/15743917/
- Sekine M, Okamoto K, Pai EF, Nagata K, Ichida K, et al. Allopurinol and oxypurinol differ in their strength and mechanisms of inhibition of xanthine oxidoreductase. Journal of Biological Chemistry. 2023;299(9):105189. doi:10.1016/j.jbc.2023.105189. PMID: 37625592. https://pubmed.ncbi.nlm.nih.gov/37625592/
- Becker MA, Schumacher HR Jr, Wortmann RL, MacDonald PA, Eustace D, Palo WA, Streit J, Joseph-Ridge N. Febuxostat compared with allopurinol in patients with hyperuricemia and gout. New England Journal of Medicine. 2005;353(23):2450-2461. doi:10.1056/NEJMoa050373. PMID: 16339094. https://pubmed.ncbi.nlm.nih.gov/16339094/
- White WB, Saag KG, Becker MA, et al. Cardiovascular Safety of Febuxostat or Allopurinol in Patients with Gout. New England Journal of Medicine. 2018;378(13):1200-1210. doi:10.1056/NEJMoa1710895. PMID: 29527974. https://pubmed.ncbi.nlm.nih.gov/29527974/
- Mackenzie IS, Ford I, Nuki G, et al. Long-term cardiovascular safety of febuxostat compared with allopurinol in patients with gout (FAST). The Lancet. 2020;396(10264):1745-1757. doi:10.1016/S0140-6736(20)32234-0. PMID: 33181081. https://pubmed.ncbi.nlm.nih.gov/33181081/
- Tardif JC, Kouz S, Waters DD, et al. Efficacy and Safety of Low-Dose Colchicine after Myocardial Infarction. New England Journal of Medicine. 2019;381(26):2497-2505. doi:10.1056/NEJMoa1912388. PMID: 31733140. https://pubmed.ncbi.nlm.nih.gov/31733140/