D3.256 - Is an Early-Type Hypersensitivity Reaction Possible with Both Peroral and Parenteral Anticoagulant Drugs? A Successful 2-Day Peroral Desensitization Protocol to Rivaroxaban

Objective: Immediate hypersensitivity reactions (HSRs) are rarely observed toward new-generation anticoagulants. Rapid drug desensitization (RRD) is needed when there is no alternative successful treatment for the patient. We aimed to present the first successful RRD in the literature with rivaroxaban in patients with early-type HSRs to both peroral (po) and parenteral anticoagulants.

Case: A 42-year-old female patient was started on intravenous heparin treatment and po rivaroxaban after lifelong anticoagulation was planned due to deep vein thrombosis history and Factor V Leiden mutation. Two hours after the first use of rivaroxaban, a non-IgE-mediated anaphylaxis-like picture developed, and subcutaneous enoxaparin and po warfarin treatments were tried, but non-Immunoglobulin E (IgE)-mediated anaphylaxis developed with the first dose of these agents, and sc tinzaparin was started. The patient, who used tinzaparin for one year, had shortness of breath and widespread erythema on the body, and the treatment was terminated. Then, fondaparinux was brought from abroad and the treatment was continued. During the follow-up, apixaban and rivaroxaban were applied by the hematology department due to the inability to obtain medication from abroad, and she was referred to us after non-IgE-mediated anaphylaxis developed with both agents. Due to the plan to return to rivaroxaban in her treatment, drug desensitization with peroral tablets was planned. Since there is no existing protocol in the literature, a peroral 2-day desensitization protocol was created in consultation with the Clinical Pharmacy Department (Table 1). Rivaroxaban 20 mg tablet was prepared by diluting it with physiological serum. Methylprednisolone 80 mg, montelukast 10 mg, cetirizine 10 mg, pheniramine 45.5 mg, and famotidine 40 mg were applied before HID. Seven-step, successful RDD; starting with 0.2 mg rivaroxaban and increasing the dose every half hour, 22.6 mg cumulative drug dose was administered in 180 minutes without any problems. The patient, who was planned to receive a single dose of 20 mg per day, received 20 mg of rivaroxaban the next day without any problems.

Conclusion: RDD is an effective and safe method in the presence of appropriate physical conditions and an experienced team. We have developed and presented the first successful RDD protocol with rivaroxaban in the literature in our department.