For most injections, 1 percent lidocaine or to percent bupivacaine is mixed with a corticosteroid preparation. The dose of anesthetic varies from mL for a flexor tendon sheath (trigger finger) to 5 to 8 mL for larger joints. On rare occasions, patients exhibit signs of anesthetic toxicity, including flushing, hives, chest or abdominal discomfort, and nausea. It can take as long as 20 to 30 minutes following the injection for these symptoms to present. For this reason, and to monitor for allergic reactions, patients should be observed in the office for at least 30 minutes following the injection.
In patients with the adrenogenital syndrome , a single intramuscular injection of 40 mg every two weeks may be adequate. For maintenance of patients with rheumatoid arthritis , the weekly intramuscular dose will vary from 40 to 120 mg. The usual dosage for patients with dermatologic lesions benefited by systemic corticoid therapy is 40 to 120 mg of methylprednisolone acetate administered intramuscularly at weekly intervals for one to four weeks. In acute severe dermatitis due to poison ivy, relief may result within 8 to 12 hours following intramuscular administration of a single dose of 80 to 120 mg. In chronic contact dermatitis, repeated injections at 5 to 10 day intervals may be necessary. In seborrheic dermatitis, a weekly dose of 80 mg may be adequate to control the condition.
Early trials of intra-articular corticosteroids showed equal systemic absorption of methylprednisolone in patients with rheumatic and osteoarthritic hands 42 and knees. 43 This suggests that steroid pharmacokinetics, rather than disease-related factors, should guide steroid selection. A recent review by the National Health Service of the United Kingdom 44 recommends triamcino-lone and methylprednisolone as preferred agents for injection of large joints (., knee). For smaller joints (., finger), either hydrocortisone or methylprednisolone (Hydeltrasol, brand no longer available in the United States) is recommended. Tables 5 and 6 45 compare commonly available steroid preparations.