Aim and objectives To analyse the profile of pharmacological interactions with RTV as an enhancer of PIs and their severity. Material and methods A retrospective observational study was conducted where patients undergoing treatment for HIV-1 infection with PI boosted with RTV before 2018 were reviewed. Patients who had been treated with RTV as an enhancer for at least 6 months were selected. Those that presented some interaction with PI/enhancer were reviewed. Data were collected on age, sex, drug interactions and their severity, and medical action/decision. The data were obtained from the drug dispensing register of the outpatient pharmaceutical care unit and the electronic clinical record. Interactions and their severity were reviewed using www.hivdruginteractions.org/checker. Results 210 patients were reviewed, of whom 5 patients (2.38%) had interactions that motivated treatment modification, reflected in the clinical history, with a mean age of 52 years (SD 5).. RTV-triazolam: avoid co-administration. RTV can increase triazolam concentrations resulting in prolonged sedation or respiratory depression. Decision: ART modification. . RTV-sildenafil: potential interaction. Co-administration of darunavir/RTV (400/100 mg twice daily) and a single dose of sildenafil resulted in fourfold greater exposure. Decision: use sildenafil single dose at a maximum 25 mg every 48 hours. . RTV-quetiapine: avoid co-administration. Concomitant administration of RTV and quetiapine is contraindicated because it can increase the toxicity related to quetiapine due to its metabolism mainly by CYP3A4, which RTV inhibits. Decision: reduce quetiapine dose to one-sixth if administered jointly. . RTV-atorvastatin: very low evidence interaction. Coadministration may increase atorvastatin concentrations and increase the risk of myopathy. Decision: exchange for pravastatin. . RTV-anti-VHC (ombitasvir+paritaprevir/RTV): avoid coadministration. Co-administration with additional ritonavir is not recommended. Optional decision: modification of ART until the end of anti-HCV treatment. Conclusion and relevanceInteractions related to ART based on PI/enhancer can be easily managed to avoid causing harm to the patient. It is necessary to review the complete treatment in ART patients whenever they start a new drug.

AimsTreatment with dihydropyrimidines poses a significant risk of serious adverse reactions for patients with dihydropyrimidine dehydrogenase (DPD) deficiency. This study seeks to analyse the correlation between DPD deficiency and plasmatic uracil values in patients who are candidates for a fluoropyrimidine scheme. It also studies the incidence of adverse events (AEs) in patients with DPD deficiency established with plasmatic uracil determination.MethodsThis was a retrospective observational study conducted in a tertiary level establishment from September 2020 to April 2021. Patients included were diagnosed with gastrointestinal tumours, were of good status, and were initiated into a fluoropyrimidine-based regimen. The incidence and grade of AEs, according Common Terminology Criteria for Adverse Events (CTCAE), were collected and compared in patients with and without DPD deficiency.Results119 patients diagnosed with gastrointestinal cancer met the inclusion criteria. In 92 (77%) patients there was no DPD deficiency according to plasmatic uracil thresholds. In the group of patients without deficit, dose reductions oscillated between 10–25% (mean 17.4%). In the no DPD deficiency group, 43 (46%) patients experienced AEs. Patients who had a DPD deficiency according to plasmatic uracil measurements were started on a 5-fluorouracil (5-FU) regimen with a dose reduction of 15–50% (mean 35%). In this group, 12 patients (44%) experienced some AEs.ConclusionNew research is needed to clarify the correlation between plasma uracil values and DPD deficiency to achieve an optimal balance between clinical benefit and toxicity.

psoriasis. Median age was 50.7 years (range 5.9-91.7) and 221 (61.9%) patients were men. 282 patients (79%) were treated with only one biological drug: 75 patients with anti-TNF-a, 132 with anti-IL-17 and 75 with anti-IL-23. 65 patients (18.2%) were treated with two biological drugs in sequence (table 1). Conclusion and relevance More than 97% of patients were treated with only one (79%) or two (18.2%) biological drugs for moderate-to-severe plaque psoriasis, with a prevalence of anti-IL-17. Further investigation of the causes for the change from one to another biological drug is needed. These could include adverse events, ineffectiveness or other reasons.

in 2.6%. At least 41% of the patients had been treated with PPIs for more than a year; for the rest of the patients, no prescription data were available prior to joining the pharmacy service. The mean number of drugs prescribed per patient was 8.3±5, 1.2% were being treated with an NSAID, 42.3% were taking acetylsalicylic acid concomitantly at antiplatelet doses and 3.8% were given bisphosphonates. The prevalence of patients being treated with a PPI and with a history of fracture was 48.7%. Conclusion and relevance There was a high prevalence of patients without a clear indication for the prescription of PPIs in the GHC. This makes it necessary to review the treatments to assess possible deprescription of these drugs. In addition, their administration could be related to an increased risk of fractures due to its high prevalence.

medications which require the user to pass through such selection and confirmation steps were far less prevalent in the near miss lookalike-soundalike error group.