Side effects are minimized by taking the lowest doses possible (that still yields positive results) and following doctor's orders. It is important to avoid self-regulation of the dosage, either by adding more or stopping the drug without a schedule. After prolonged use, steroids must be gradually reduced to permit the adrenal glands to resume natural cortisol production. Eliminating doses too quickly can result in glucocorticoid withdrawal symptoms, worsening of underlying inflammatory disease (rebound effect), or rarely, adrenal crisis (a life-threatening state caused by insufficient levels of adrenal steroids).
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.
Kenalog in blood - Derby et al. "Size and aggregation of corticosteroids used for epidural injections"