22-year-old woman, bipulmonary transplanted in March 2014 due to cystic fibrosis. The donor had positive serology for CMV, while the recipient was negative. A few days after transplantation, ganciclovir prophylaxis was started, and later, when the patient tolerated the oral route, valganciclovir was switched to valganciclovir. Viral load controls during prophylaxis were negative in the recipient until the 6th month after transplantation, when viral load was detected in the controls (2,090 IU/ml) without stopping prophylaxis. The patient was admitted to our hospital and started intravenous treatment with ganciclovir; however, one month after starting intravenous therapy, the positive viral load persisted and even increased to 42,400 IU/ml. Due to this, a resistance study was carried out, and it was found to be resistant to ganciclovir, so he was switched to foscarnet. With this drug, the viral load was negatived, but not without certain adverse effects such as hypomagnesaemia. This meant that the immunosuppressive treatment had to be modified, changing cyclosporine for everolimus, as the former can produce the same alteration8.
When the viral load became negative with foscarnet, treatment was suspended, with fortnightly check-ups.
After two months without treatment, the viral load had increased to 13,665 IU/ml, at which point a request was made to the Pharmacy Service for compassionate use of maribavir, with the intention that the patient would receive oral therapy instead of intravenous therapy.
While arrangements were being made to obtain maribavir, the patient started treatment again with oral valganciclovir. Because of the expected delay in obtaining maribavir, and given the urgency of the case, the physicians in charge of the patient considered the off-label use of leflunomide. This request was reported by the Pharmacy Department to the Hospital's Medical Directorate, which authorised the use of leflunomide in this patient.
Once leflunomide was available to start treatment, valganciclovir was discontinued. At this time (March 2015) the patient had a viral load of 17,344 IU/mL. The initial regimen was 100 mg daily for the first five days, followed by 20 mg every 12 hours. Fifteen days after starting treatment the viral load had decreased to 531 IU/mL, becoming undetectable within a month. Six months after starting leflunomide the patient maintained an undetectable viral load with no adverse drug effects.