The most commonly reported side effects were: oral thrush , nausea , headache , and pain in the pharynx or larynx . More rarely reported side effects (occurring in <1% of patients during the clinical trial) include: tachycardia , palpitations , dry mouth , allergic reaction ( bronchospasm , dermatitis , hives ), pharyngitis , muscle spasms , tremor , dizziness , insomnia , nervousness , and hypertension . Patients experiencing an allergic reaction or increase in difficulty breathing while using this medication should immediately discontinue its use and contact their physician. 
There is no clinical syndrome associated with an overdosage of cromolyn sodium . In several animal species acute toxicity with cromolyn sodium occurs only with very high exposure levels. No deaths occurred at the highest oral doses tested in mice, 8,000 mg/kg (approximately 5,100 and 2,700 times the maximum recommended daily inhalation doses in adults and children, respectively, on a mg/m 2 basis) or in rats, 8,000 mg/kg (approximately 10,000 and 5,400 times the maximum recommended daily inhalation doses in adults and children, respectively, on a mg/m 2 basis).