The drug's most common side effects are poor or reduced appetite, vomiting, lack of energy, diarrhea, and weakness. Occasionally, more serious side effects, including bloody diarrhea, collapse, severe sodium/potassium imbalance, and destruction of the adrenal gland may occur, and may result in death. In 2014, with input from CVM, the manufacturer updated the information about patient monitoring and side effects on the package insert. Although not proven to be caused by Vetoryl, some additional side effects reported to CVM and now included on the package insert are adrenal insufficiency, shaking, elevated liver enzymes and elevated kidney tests.
A randomised, double-blind, placebo-controlled study compared the efficacy of Pulmicort Respules and placebo in the treatment of croup in 83 infants and children (aged 6 months to 8 years) admitted to hospital for croup. Patients received either Pulmicort Respules 2 mg or placebo every 12 h for a maximum of 36 h or until discharge from hospital. The total croup symptom score was assessed at 0, 2, 6, 12, 24, 36 and 48 hours after the initial dose. At 2 hours, both the Pulmicort Respules and placebo groups showed a similar improvement in croup symptom score, with no statistically significant difference between the groups. By 6 hours, the croup symptom score in the Pulmicort Respules group was statistically significantly improved compared with the placebo group, and this improvement versus placebo was similarly evident at 12 and 24 hours.