The description of adverse reactions is based on events from clinical studies (approximately 200 patients) conducted prior to 1986, and the controlled trial of aerosolized Ribavirin for Inhalation Solution, USP conducted in 1989-1990. Additional data from spontaneous post-marketing reports of adverse events in individual patients have been available since 1986.

Deaths

Deaths during or shortly after treatment with aerosolized Ribavirin for Inhalation Solution, USP have been reported in 20 cases of patients treated with Ribavirin for Inhalation Solution, USP (12 of these patients were being treated for RSV infections). Several cases have been characterized as “possibly related” to Ribavirin for Inhalation Solution, USP by the treating physician; these were in infants who experienced worsening respiratory status related to bronchospasm while being treated with the drug. Several other cases have been attributed to mechanical ventilator malfunction in which Ribavirin for Inhalation Solution, USP precipitation within the ventilator apparatus led to excessively high pulmonary pressures and diminished oxygenation. In these cases the monitoring procedures described in the current package insert were not employed (see Description of Studies, WARNINGS, and DOSAGE AND ADMINISTRATION).

Pulmonary and Cardiovascular

Pulmonary function significantly deteriorated during aerosolized Ribavirin for Inhalation Solution, USP treatment in six of six adults with chronic obstructive lung disease and in four of six asthmatic adults. Dyspnea and chest soreness were also reported in the latter group. Minor abnormalities in pulmonary function were also seen in healthy adult volunteers.

In the original study population of approximately 200 infants who received aerosolized Ribavirin for Inhalation Solution, USP, several serious adverse events occurred in severely ill infants with life-threatening underlying diseases, many of whom required assisted ventilation. The role of Ribavirin for Inhalation Solution, USP in these events is indeterminate. Since the drug’s approval in 1986, additional reports of similar serious, though non-fatal, events have been filed infrequently. Events associated with aerosolized Ribavirin for Inhalation Solution, USP use have included the following:

Pulmonary: Worsening of respiratory status, bronchospasm, pulmonary edema, hypoventilation, cyanosis, dyspnea, bacterial pneumonia, pneumothorax, apnea, atelectasis and ventilator dependence.

Cardiovascular: Cardiac arrest, hypotension, bradycardia and digitalis toxicity. Bigeminy, bradycardia and tachycardia have been described in patients with underlying congenital heart disease.

Some subjects requiring assisted ventilation experienced serious difficulties, due to inadequate ventilation and gas exchange. Precipitation of drug within the ventilatory apparatus, including the endotracheal tube, has resulted in increased positive end expiratory pressure and increased positive inspiratory pressure. Accumulation of fluid in tubing (“rain out”) has also been noted. Measures to avoid these complications should be followed carefully (see DOSAGE AND ADMINISTRATION).

Hematologic

Although anemia was not reported with use of aerosolized Ribavirin for Inhalation Solution, USP in controlled clinical trials, most infants treated with the aerosol have not been evaluated 1 to 2 weeks post-treatment when anemia is likely to occur. Anemia has been shown to occur frequently with experimental oral and intravenous Ribavirin for Inhalation Solution, USP in humans. Also, cases of anemia (type unspecified), reticulocytosis and hemolytic anemia associated with aerosolized Ribavirin for Inhalation Solution, USP use have been reported through post-marketing reporting systems. All have been reversible with discontinuation of the drug.

Other

Rash and conjunctivitis have been associated with the use of aerosolized Ribavirin for Inhalation Solution, USP. These usually resolve within hours of discontinuing therapy. Seizures and asthenia associated with experimental intravenous Ribavirin for Inhalation Solution, USP therapy have also been reported.