Brinzolamide

7 DRUG INTERACTIONS • There is a potential additive effect of the known systemic effects of carbonic anhydrase inhibition in patients receiving both oral and topical carbonic anhydrase inhibitors. ( 7.1 ) • Rare instances of acid-base alterations have occurred with high-dose salicylate therapy. ( 7.2 )

7.1 Oral Carbonic Anhydrase Inhibitors There is a potential for an additive effect on the known systemic effects of carbonic anhydrase inhibition in patients receiving an oral carbonic anhydrase inhibitor and AZOPT. The concomitant administration of AZOPT and oral carbonic anhydrase inhibitors is not recommended.

7.2 High-Dose Salicylate Therapy Carbonic anhydrase inhibitors may produce acid-base and electrolyte alterations. These alterations were not reported in the clinical trials with brinzolamide. However, in patients treated with oral carbonic anhydrase inhibitors, rare instances of acid-base alterations have occurred with high-dose salicylate therapy. Therefore, the potential for such drug interactions should be considered in patients receiving AZOPT.

8.1 Pregnancy Risk Summary There are no adequate and well-controlled studies in pregnant women to inform drug-associated risk. In reproductive toxicity studies, brinzolamide administered orally to rats induced fetal toxicity at 375 times the recommended human ophthalmic dose (RHOD) based on mg/kg. In rabbits, no fetal toxicity was observed following oral administration (see Data) . The background risk of major birth defects and miscarriage for the indicated population is unknown; however, in the U.S. general population, the estimated background risk of major birth defects is 2% to 4%, and of miscarriage is 15% to 20%, of clinically recognized pregnancies.

Data Animal Data Embryo-fetal studies were conducted in pregnant rats administered 0, 2, 6, or 18 mg/kg/day brinzolamide by oral gavage on gestation days 6 to 17, to target the period of organogenesis. Decreased fetal body weight with reduced skeletal ossification were observed at 18 mg/kg/day (375 times the RHOD based on mg/kg). The no-observed-adverse-effect-level (NOAEL) for fetal toxicity was 6 mg/kg/day (125 times the RHOD). Decreased maternal weight gain was observed at 18 mg/kg/day. The NOAEL for maternal toxicity was 6 mg/kg/day (125 times the RHOD).

Embryo-fetal studies were conducted in pregnant rabbits administered 0, 1, 3, or 6 mg/kg/day of brinzolamide by oral gavage on gestation days 6 to 18, to target the period of organogenesis. No treatment-related fetal effects were observed at any dose. The NOAEL for fetal toxicity was 6 mg/kg/day (125 times the RHOD based on mg/kg). Maternal weight loss during pregnancy was observed at 3 mg/kg/day (63 times the RHOD) and above. The NOAEL for maternal toxicity was 1 mg/kg/day (21 times the RHOD). A peri-/postnatal study was conducted in rats administered brinzolamide by oral gavage from gestation day 16 through lactation day 20.

Decreased pup body weight was observed at 15 mg/kg/day (313 times the RHOD based on mg/kg). The NOAEL for developmental toxicity was 5 mg/kg/day (104 times the RHOD). Following oral administration of 14 C-brinzolamide to pregnant rats, radioactivity was found to cross the placenta and was present in the fetal tissues and blood.