2023 FSA Podium and Poster Abstracts
P058: AN UNUSUAL POSTPARTUM HYPERSENSITIVITY REACTION TO TRANEXAMIC ACID
Stephan Mouhanna, MD1; Tilman Chambers, MD1; Maria Frosth, MD2; Benjamin Houseman, MD, PhD, FASA2; 1Memorial Healthcare System; 2Envision Physician Services
The lysine analog tranexamic acid (TXA) has found widespread use for the reduction of bleeding in the perioperative setting. The WOMAN trial, for example, demonstrated that early administration of TXA during postpartum hemorrhage improved survival (1). Although TXA has an excellent safety profile, adverse drug reactions (ADR) to TXA have been reported (2). Most ADRs are Type 1 hypersensitivity reactions (T1HR), but cases of T-cell mediated drug eruptions have also been described (3). Here we describe a likely TXA ADR during repeat cesarean section in an otherwise healthy parturient.
A 36-year-old G5P1031 at 39 weeks and 2 days gestation was admitted for a repeat C-section. She had an uncomplicated prenatal course, and medical history was significant for childhood penicillin allergy. Spinal anesthesia (1 mL 0.75% bupivicaine with morphine 150 mcg and fentanyl 15 mcg) was administered uneventfully, followed by clindamycin and gentamicin for surgical site infection prophylaxis. A phenylephrine infusion and intermittent doses of ephedrine were utilized to maintain blood pressure. A healthy infant was delivered with APGAR scores of 8 of 9. Despite post-delivery oxytocin administration, EBL was elevated, requiring additional IV access as well as administration of 5% albumin (250 mL) and TXA 1g IV. Blood pressure remained stable throughout and total EBL was 1862 mL. Upon removal of the drapes, urticaria were noted on the patient's torso and limbs. Famotidine, Dexamethasone, and Diphenhydramine were administered intravenously with resolution of symptoms. The remainder of the patient’s hospital course was uneventful, and both mother and baby were discharged on hospital day 3 with a referral for allergy testing.
In addition to its role in reduction of perioperative bleeding, TXA has also found utility as a treatment for some types of angioedema and chronic urticaria because it inhibits the production of bradykinin (Figure 1A). The anti-inflammatory properties of TXA make it an unusual suspect for hypersensitivity reactions, yet case reports have documented a range of TXA-mediated ADRs (2-4). The ADR in our case was not a T1HR, suggesting a T-cell mediated mechanism. For patients with a suspected adverse reaction to TXA, aminocaproic acid should be avoided because it structurally resembles TXA. Ethamsylate, which is chemically distinct and improves platelet adhesiveness by impacting cyclooxygenase metabolism, is a suitable alternative (4).
The urticaria observed in our case could have resulted from multiple medications, including intrathecal opiates and antibiotics. However, each of these medications had been administered previously to this patient without issue, and the reaction occurred shortly after TXA administration. In this case we were unable to obtain a tryptase level to support a hypersensitivity reaction and the patient did not obtain formal allergy testing, which is necessary to confirm TXA as the causative agent (2).
References:
1) DOI: 10.1186/s12884-018-1855-5
2) DOI: 10.1186/s12948-020-00131-8
3) DOI: 10.1111/j.1365-2133.1993.tb15161.x.
4) DOI: 10.1097/01.mjt.0000158336.62740.54.
