Background Hazard vulnerability analysis (HVA) is a method that provides a systematic approach to identifying the hazards and the direct and indirect effects that they have on the hospital pharmacy.

Purpose The objective of this study was to identify the phases at the greatest risks, to find solutions to reduce the risk level and to enhance patient safety.

Material and methods We have adapted this method to all the stages of drug compounding. We analysed 45 different events concerning the preparations of drugs. For each process, a score of 0 to 3, has been assigned for the following items: probability of the event happening (0=none/unknown; 1=low; 2=moderate; 3=high); magnitude of impact divided into human impact (probability of death or injury), property impact (physical losses and damages) and business impact (interruption of services) (0=none/unknown; 1=low, 2=moderate, 3=high); and mitigation factors divided into preplanning, internal response and external response (0=none/unknown, 1=high, 2=moderate, 3=low). The severity of the event determined using the difference between the magnitude of impact and the degree of mitigation. The risk was obtained by multiplying the probability by the severity.

Results Only 6/45 (13.3%) of all phases showed a risk of more than 50%. The risk related to the lack of prescription and, consequently, preparation made after a doctor’s call, was 52%. The risk related to the preparation of the drug that caused allergy to the patient noted in the electronic medical record was 56%. The risk due to the preparation of the drug that caused interactions with other drugs administered to the patient was 52%. The risk of the wrong quantity of drug prepared was 67%. The risk related to the error in the choice of the solvent to be used was 52%. The risk due to incorrect labelling was 56%.

Conclusion Based on these results, we have identified some solutions to reduce the risk: the double-check carried out by two different people could solve the risk due to incorrect labelling; and the software used by pharmacists can be improved to reduce the risk related to the patients’ allergy or cross-reaction. Finally, errors can be reduced through clearer and specific sessions of training for the compounders.

References and/or acknowledgements No conflict of interest.