Intra-articular glucocorticoid therapy is appropriate for this patient. Intra-articular glucocorticoid injections are a good treatment strategy when only one or two joints are affected, the presence of joint infection has been ruled out, and oral therapies have potential adverse events. This patient has a history of gout and currently presents with evidence of an acute gouty attack in the knee. Given the synovial fluid leukocyte count (<50,000/µL [50 × 10⁹/L]), the documented presence of intracellular crystals, and the negative synovial fluid Gram stain, the probability of a joint infection is very low. The onset of gout in this patient was preceded by community-acquired pneumonia, which may have promoted the gout attack by causing fever and dehydration. Treatment for acute gout should focus on anti-inflammatory therapy, typically using colchicine, an NSAID, or a glucocorticoid. Although all three would effectively treat this patient's gout, the best choice would be an intra-articular glucocorticoid because of potential adverse effects of the other anti-inflammatories. Although both systemic and local glucocorticoid therapy are effective in treating acute gout, intra-articular glucocorticoids are preferred in this patient to avoid systemic immunosuppressive effects in the setting of resolving pneumonia and the possible adverse impact of systemic glucocorticoids in a patient with diabetes mellitus.

Acetaminophen is analgesic but not anti-inflammatory and does not promote the resolution of a gouty attack.

Colchicine effectively treats acute gout, especially in the early phases of an attack. However, colchicine is metabolized by the hepatic CYP3A4 enzyme, which clarithromycin strongly inhibits; coadministration raises the risk of colchicine toxicity and even death, and colchicine should be avoided while this patient is taking clarithromycin.

The presence of significant kidney disease makes the use of an NSAID such as indomethacin undesirable because cyclooxygenase inhibition adversely affects the kidneys.