Gout, colchicine allopurinol

Drugs used in the treatment of gout Colchicine Allopurinol Uricosuric agents... 

Allopurinol (Zyloprim) reduces the production of uric acid, thus decreasing serum uric acid levels and the deposit of urate crystals in joints. The exact mechanism of action of colchicine is unknown, but it does reduce the inflammation associated with the deposit of urate crystals in the joints. This probably accounts for its ability to relieve the severe pain of acute gout. Colchicine has no effect on uric acid metabolism. 

For patients with chronic gout, colchicine has established value as a prophylactic agent, especially when there is frequent recurrence of attacks. Prophylactic medication also is indicated upon initiation of long-term medication with allopurinol or the uricosuric agents, because acute attacks often increase in frequency during the early months of such therapy. 

Gout is a metabolic disease in which there is a overproduction of purines. It is characterized by intermittent attacks of acute arthritis produced by the deposition of sodium urate crystals in the synovial tissue of joints. Drugs used for treating gout are allopurinol, probenecid, colchicine, and NSAIDs. 

The options available are allopurinol, probenecid (named patient only) and sulfinpyrazone. Allopurinol is the drug usually chosen as a first line agent for the prevention of gout. Colchicine may be given at a dose of 500 micrograms twice or three times daily when allopurinol or uricosuric drugs are initially commenced in order to prevent an attack of gout. NSAIDs may also be used but this would not be an appropriate option for Mr KT. 

Be aware of treatment of gout with allopurinol and colchicine. 

The aims of treatment are to decrease the symptoms of an acute attack, decrease the risk of recurrent attacks, and lower serum urate levels. Therapy of gout focuses on colchicine, allopurinol, and the uricosuric agents—probenecid, sulfinpyrazone, and ben7,bromarone. 

The active principle of the autumn crocus (Colchicum autumnale), colchicine (48), is one of the very few drugs that have remained in reputable medical use since ancient times. This drug was the only useful treatment available for the excruciating pain associated with crystallization of uric acid in the joints characteristic of gout until the advent of allopurinol. Although the precise mechanism by which colchicine gives this dramatic relief remains undefined, the antimitotic activity of this agent is... 

Allopurinol is well absorbed with a short half-life of 2 to 3 hours. The half-life of oxypurinol approaches 24 hours, allowing allopurinol to be dosed once daily. Oxypurinol is cleared primarily renally and can accumulate in patients with reduced kidney function. Allopurinol should not be started during an acute gout attack because sudden shifts in serum uric acid levels may precipitate or exacerbate gouty arthritis. Rapid shifts in serum uric acid can change the concentration of monosodium urate crystals in synovial fluid, causing more crystals to precipitate. Thus some clinicians advocate a prophylactic dose of colchicine (0.6 mg/day) during initiation of antihyperuricemic therapy. Acute episodes should be treated appropriately before maintenance treatment is started. 

Management of an acute attack of gout involves the use of high doses of nonsteroidal anti-inflammatory agents (NSAIDs). Colchicine is useful in patients with heart failure where the use of NSAIDs is contraindicated because of water retention. Allopurinol and other uricosuric agents are not indicated for acute attacks as they may aggravate the condition. The use of an intra-articular corticosteroid injection in gout is unlicensed. 

Increased acute attacks of gout during early stages of allopurinol administration— cover with colchicine... 

As with allopurinol, prophylactic treatment with colchicine or NSAIDs should start at the beginning of treatment to avoid gout flares. The most frequent treatment-related adverse events are liver function abnormalities, diarrhea, headache, and nausea. Febuxostat appears to be well tolerated in patients with a history of allopurinol intolerance. 

If properly controlled, simple gout may have few adverse effects. However, the severe neurological symptoms of Lesch-Nyhan syndrome (Section E,2 of text)6 cannot be corrected by medication. Colchicine (Box 7-D), in a manner which is not understood, alleviates the painful symptoms of gout caused by the deposits of sodium urate in joints and tissues. It is also important to keep the dietary purine intake low and it is often necessary to inhibit xanthine oxidase. A widely used and effective inhibitor is the isomer of hypoxanthine known as allopurinol, which is taken daily in amounts of 100 -600 mg or more. 

In a pathological condition that causes pain, drugs may be used either to care for the acute attack of pain or as prophylaxis to prevent the occurrence of pain. For example, colchicine is used during an acute attack of gout, and after the pain has subsided initially, the patient is switched to uricosuric agents such as probenecid or an inhibitor of uric acid synthesis such as allopurinol. 

Acute gout is usually treated with an NSAID in full dose. Any such drug which is tolerated may be used (except aspirin which in low dose promotes urate retention, see below) indomethacin is often chosen because of its strong anti-inflammatory action and efficacy. If treatment is started early, the attack may be terminated in a few hours. Colchicine is useful if NSAIDs are contraindicated. If neither colchicine nor NSAIDs are tolerated, oral prednisolone 40 mg/d and tapered over a week is also effective. It requires only a moment s thought to appreciate that the uricosurics and allopurinol will not relieve an acute attack of gout. 

Acute gout can be exacerbated at the beginning of allopurinol treatment unless the drug is combined with colchicine or an anti-inflammatory drug (18). 

Kot TV, Day RO, Brooks PM. Preventing acute gout when starting allopurinol therapy. Colchicine or NSAIDs Med J Aust 1993 159(3) 182-4. 

Gout is treated with diet and with several drugs. Dietary control (i.e., reduced consumption of food that is rich in nucleic acids such as liver and sardines) depresses uric acid synthesis in some individuals who are susceptible to primary gout. Allopurinol and colchicine are often used in gout therapy. Because allopurinol... 

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