4CPS-068 Intravenous levomepromazine in the treatment of cutaneous rash due to suspected drug hypersensitivity: a case report

<h3>Background and Importance</h3> Drug hypersensitivity reactions are a diverse group of immune-mediated reactions following exposure to a medication, and their diagnosis can be challenging. Upon suspicion, the offending drug should be discontinued. Treatment varies based on symptom severity and may include antihistamines, corticosteroids, and adrenaline.¹ The presented case is notable for the successful use of intravenous levomepromazine in treating refractory drug-induced rash. <h3>Aim and Objectives</h3> The aim is to describe the multidisciplinar management of a 19-year-old female with no oral route available who suffered unresponsive cutaneous rash due to suspected drug hipersensitivity. <h3>Material and Methods</h3> The patient was hospitalised with diagnosis of septic shock and a pseudo-obstructive syndrome. Following surgical intervention and a complex pharmacological treatment, the patient developed a severe pruritic erythematous rash. Intravenous dexchlorpheniramine was initiated and administration of beta lactamics, sulfonamides and pyrazolones was prohibited. As no response was observed, intravenous and topical methylprednisolone was added and omeprazole, orthopramides, alpha-adrenergic agonists and macrolides were discontinued. Patient’s clinical status, including eosinophil count, liver enzymes, and renal function, was closely monitored. Due to the worsening rash and refractory pruritus, allergists decided to contact Pharmacy Service in order to search for an alternative intravenous treatment option. <h3>Results</h3> Since oral administration was not an option and no intravenous H1-antagonist were available in our country, other than dexchlorpheniramine, the use of levomepromazine was suggested. It has a phenothiazine chemical structure, similar to other H1-antagonist drugs. We recommended to start a continuous infusion of 12,5 mg in 500mL of dextrose 5% in an off-label,² compassionate use scenario.³ Soon the patient showed significant improvement in pruritus and a reduction in erythema and infiltration of the rash which allowed corticoesteroid tapering and eventual discontinuation of levomepromazine few days after. <h3>Conclusion and Relevance</h3> This case highlights the potential use of intravenous levomepromazine for treating refractory drug hypersensitivity reactions. It also underscores the importance of a multidisciplinary approach and contributes to the limited body of literature available. <h3>References and/or Acknowledgements</h3> Hausmann O. Drug allergy. <i>Middleton’s Essential Allergy</i> 2017. Sanofi-aventis Canada Inc. Product monograph Nozinan 2006, https://pdf.hres.ca/dpd_pm/00002959.PDF Fekete Z. Control of pruritus with levomepromazine. <i>Appl Ther</i>. 1963;<b>5</b>:333–4. <h3>Conflict of Interest</h3> No conflict of interest