PRECAUTIONS General Patients may experience a transient stinging or burning sensation following application of Cromolyn Sodium Ophthalmic Solution USP, 4%. The recommended frequency of administration should not be exceeded (see DOSAGE AND ADMINISTRATION). Information for Patients Patients should be advised to follow the patient instructions listed on the Information for Patients sheet. Users of contact lenses should refrain from wearing lenses while exhibiting the signs and symptoms of vernal keratoconjunctivitis, vernal conjunctivitis, or vernal keratitis. Do not wear contact lenses during treatment with Cromolyn Sodium Ophthalmic Solution USP, 4%. Carcinogenesis, Mutagenesis, Impairment of Fertility Long-term studies of cromolyn sodium in mice (12 months intraperitoneal administration at doses up to 150 mg/kg three days per week), hamsters (intraperitoneal administration at doses up to 52.6 mg/kg three days per week for 15 weeks followed by 17.5 mg/kg three days per week for 37 weeks), and rats (18 months subcutaneous administration at doses up to 75 mg/kg six days per week) showed no neoplastic effects. The average daily maximum dose levels administered in these studies were 192.9 mg/m2 for mice, 47.2 mg/m2 for hamsters and 385.8 mg/m2 for rats. These doses correspond to approximately 6.8, 1.7 and 14 times the maximum daily human dose of 28 mg/m2. Cromolyn sodium showed no mutagenic potential in the Ames Salmonella/microsome plate assays, mitotic gene conversion in Saccharomycas cerevisiae and in an in vitro cytogenetic study in human peripheral lymphocytes. No evidence of impaired fertility was shown in laboratory reproduction studies conducted subcutaneously in rats at the highest doses tested, 175 mg/kg/day (1050 mg/m2) in males and 100 mg/kg/day (600 mg/m2) in females. These doses are approximately 37 and 21 times the maximum daily human dose, respectively, based on mg/m2. Pregnancy Teratogenic Effects Pregnancy Category B. Reproduction studies with cromolyn sodium administered subcutaneously to pregnant mice and rats at maximum daily doses of 540 mg/kg (1620 mg/m2) and 164 mg/kg (984 mg/m2), respectively, and intravenously to rabbits at a maximum daily dose of 485 mg/kg (5820 mg/m2) produced no evidence of fetal malformation. These doses represent approximately 57, 35, and 205 times the maximum daily human dose, respectively, on a mg/m2 basis. Adverse fetal effects (increased resorption and decreased fetal weight) were noted only at the very high parenteral doses that produced maternal toxicity. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Cromolyn Sodium Ophthalmic Solution USP, 4% is administered to a nursing woman. Pediatric Use Safety and effectiveness in children below the age of 4 years have not been established.