Background Boosted protease inhibitor monotherapy may offer antiviral efficacy while reducing drug interactions, costs and toxicity in HIV infected patients.

Purpose The aim of this study was to assess the ef­ficacy of darunavir/ritonavir (DRV/r) monotherapy in a real life setting.

Material and methods A retrospective analysis of all HIV infected pa­tients, who had initiated DRV/r monotherapy between January 2009 and January 2016, was performed. Patients with previous virological control after the start, and those who were treated for at least one year with DRV/r, were included. Data analysed: sex, age, start reason, previous treatment, presence of blips and adherence based on the dispensations record of the previous 6 months. Additionally, the reason for discontinuation was analysed in those patients who discontinued treatment, and length of treatment with DRV/r was recorded. Finally, CD4 lymphocyte counts at the beginning and end of monotherapy or at the end of the study were recorded. Data were collected from clinical documentation and using computer tools(Farmatools and Intralab).

Results 53 patients started treatment with DRV/r. 71.6% (38) were men and mean age was 48 years. The reason for starting was for treatment simplification in 44%, renal impairment in 17%, gastrointestinal symptoms in 17%, dyslipidaemia in 11% and neuropsychiatric symptoms in 11.0%. Regarding previous treatment, 49.0% (26) had received triple therapy 2ITIAN+PI/r, 26.4% (14) 2ITIAN+1ITINN, 17.0% (9) PI/r (LPV/r) and 7.6% (4) different combinations. 84.0% had superior treatment adherence (90.0%). 60.4% (32) continued with DRV/r until January 2016 with a mean duration of 37.7 months. 37.5% (12) had blips in some of the controls, but in no case was this the reason for discontinuation. 39.6% (21) discontinued treatment with an average duration of 19.4 months. The reasons for discontinuation were toxicity in 9 patients (4 gastrointestinal, 2 renal, 1 neurologic, 1 interactions and 1 gestation), loss to follow-up/death in 6, blips in 4 and virological failure in 2. Mean baseline CD4 DRV/r was 693 000/mm³, maintaining ultimate control favourably with 693 000/mm³. No protease inhibitor mutations were detected.

Conclusion Boosted protease inhibitor monotherapy with DRV/r was effective in a real life setting. About 40% of patients changed to DRV/r, but neither virological failure nor blips were the fundamental reasons for change.

No conflict of interest