Acute Gouty Arthritis
The diagnosis and treatment of gouty arthritis is determined by the severity of pain, duration of attack, and extent of joint involvement. Pain assessment is commonly based on a visual analogue scale of 0 to 10 where ≤4 is mild, 5 to 6 is moderate, and ≥7 is severe. The duration of gouty arthritis is measured from the onset of gouty pain where <12 hours is early, 12 to 36 hours is well established, and >36 hours is late. The extent of an acute gouty arthritis attack is determined by the number of active joints. Gouty arthritis should be treated with pharmacologic therapy within 24 hours of attack and for up 7 to 10 days.[2,7] ULTs should be continued during an acute attack. Monotherapy with nonsteroidal anti-inflammatory drugs (NSAIDs), systemic corticosteroids, or colchicine is recommended for mild-to-moderate pain where only one or a few small joints are affected. Combination therapy is recommended for polyarticular attacks or an attack affecting multiple large joints that induce severe pain (Table 4).
Colchicine exerts its effects by reducing lactic acid production by leukocytes, which in turn decreases uric acid deposition and reduces phagocytosis, with abatement of the inflammatory response. Although an older drug, colchicine just recently obtained an FDA indication for use in patients with acute gout. Colchicine should be instituted only in early or well-established gouty attacks. In a recent randomized trial, low-dose colchicine (1.8 mg over 1 h) yielded both maximum plasma concentration and early gout-flare efficacy comparable to high-dose colchicine (4.8 over 6 h), with a safety profile indistinguishable from that of placebo.
NSAIDs inhibit the cyclooxygenase (COX) enzymes, which are involved in the inflammatory process and prostaglandin production. The three NSAIDs that are FDA approved for the treatment of acute gout are naproxen, indomethacin, and sulindac. Celecoxib, the only COX-2 inhibitor currently available in the U.S., does not have an indication for acute gout. However, celecoxib has been shown to effectively treat acute gout at high doses (800 mg/day) in a randomized study, although these doses exceed the recommended maximum daily doses.
Corticosteroids are recommended by the ACR for monotherapy, but these agents are generally reserved for patients who cannot tolerate either colchicine or NSAIDs due to their systemic adverse effects. Although the guidelines do not explicitly recommend depo formulations, these agents have been used; however, dosing is ambiguous. When selecting corticosteroids as the initial therapy, joint involvement needs to be considered (Table 4).
US Pharmacist. 2013;38(3):22-26. © 2013 Jobson Publishing