Background and Importance The use of medications in special situations is a common practice worldwide, even though it is a field with very few published studies at present. A lot of effort is spent daily in hospital pharmacy services to process requests for these medications. Knowing which medical specialties and which drugs are most commonly used in such situations can be a good policy to know what economic weight these drugs have over the total.

Aim and Objectives Analyse the drugs used in special conditions in the hospital in 2021. The specific objectives were to describe the use and budgetary impact of foreign drugs and drugs authorised under conditions other than those established in the technical data sheet. In addition, another objective was the description of the use of compassionate medicines.

Material and Methods Electronic search on the AEMPS website for drug use under special conditions.

Search for the cost of each of the foreign drugs purchased.

Data mining of individualised requests for treatment with indications not included in the prescribing information drug.

Calculation of the cost per patient of those drugs used under conditions other than those authorised in prescribing information drug.

Results 173 patients were treated with foreign drugs (55 active ingredients in 71 indications).

The foreign drugs requested the most in 2021 were thyrotropin alfa, alpha tocopheryl acetate and defibrotide. The majority corresponded to oncology and haematology requests. Total expenditure was €1,346,000.

There were 259 compassionate drug applications processed (35 active ingredients in 38 indications). Remdesivir was the most widely used compassionate drug.

Off-label drugs were validated and dispensed for 2,033 patients (108 active ingredients in 193 indications) with an expenditure of €6,308,000 in 2021.

88.2% of the off-label drug requests were made under protocols authorised by the Pharmacy Commission.

The most frequent individualised off-label drug requests were for ustekinumab and pembrolizumab, and the active ingredients with the greatest economic impact were ustekinumab and atezolizumab/bevacizumab, accounting for 25.9% of total expenditure.

Conclusion and Relevance There is a need to continue with the protocolisation of special uses to improve their knowledge and facilitate their availability. The information systems should be completed to speed up the use of data and to include requests for drugs pending funding.

Conflict of Interest No conflict of interest