Compatibility of corticosteroids and antibiotics in combination

To study the compatibility of combinations of antibiotics and steroids commonly used in anterior segment surgery.

Research Laboratory, Helsinki University, Finland.

Aggregate production in vitro and in vivo was studied for three injectable antibiotics (cefotaxime sodium, tobramycin sulfate, and gentamicin) and four corticosteroids (triamcinolone acetonide, methylprednisolone sodium succinate, methylprednisolone acetate, and dexamethasone sodium phosphate) using conventional and dark-field microscopy. Aggregate formation on collagen shields and subconjunctival aggregate formation of tobramycin sulfate in combination with methylprednisolone acetate or dexamethasone sodium phosphate was also studied.

Dexamethasone sodium phosphate (4 mg/mL) did not form aggregates with any of the three antibiotics tested. Cefotaxime sodium did not cause aggregates when 24 mg/mL of dexamethasone sodium phosphate was used both in vitro and in vivo or in association with collagen shields.

To avoid undesired side effects, such as epithelial sloughing and corneal edema after collagen shield application, antibiotics and steroids must be carefully selected.