Singh, Amteshwar

AbstractAmiodarone is an antiarrhythmic drug with a significant adverse effect profile, including neurotoxicity. While ataxia, neuropathy, and tremors are more commonly seen forms of amiodarone neurotoxicity, very few cases of nystagmus are reported. We report the case of an 86‐year‐old man who presented with abrupt‐onset ataxia, dizziness, and inability to ambulate, 10 days after initiating amiodarone for atrial fibrillation. His examination revealed gaze‐evoked nystagmus along with features of cerebellar dysfunction. After excluding other etiologies, amiodarone was stopped. His nystagmus resolved, and his ataxia improved within 48 h of stopping amiodarone. Due to the rarity of this drug‐induced adverse effect, we performed a systematic review of available case reports in the literature (PubMed and Scopus) using Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines and presented our findings. Nystagmus is a rarely reported adverse effect of amiodarone, which can occur within days to months of starting the medication. Treatment includes stopping the drug and monitoring for resolution of nystagmus.

ImportanceDirect oral anticoagulant (DOAC)–associated intracranial hemorrhage (ICH) has high morbidity and mortality. The safety and outcome data of DOAC reversal agents in ICH are limited.ObjectiveTo evaluate the safety and outcomes of DOAC reversal agents among patients with ICH.Data SourcesPubMed, MEDLINE, The Cochrane Library, Embase, EBSCO, Web of Science, and CINAHL databases were searched from inception through April 29, 2022.Study SelectionThe eligibility criteria were (1) adult patients (age ≥18 years) with ICH receiving treatment with a DOAC, (2) reversal of DOAC, and (3) reported safety and anticoagulation reversal outcomes. All nonhuman studies and case reports, studies evaluating patients with ischemic stroke requiring anticoagulation reversal or different dosing regimens of DOAC reversal agents, and mixed study groups with DOAC and warfarin were excluded.Data Extraction and SynthesisPreferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were used for abstracting data and assessing data quality and validity. Two reviewers independently selected the studies and abstracted data. Data were pooled using the random-effects model.Main Outcomes and MeasuresThe primary outcome was proportion with anticoagulation reversed. The primary safety end points were all-cause mortality and thromboembolic events after the reversal agent.ResultsA total of 36 studies met criteria for inclusion, with a total of 1832 patients (967 receiving 4-factor prothrombin complex concentrate [4F-PCC]; 525, andexanet alfa [AA]; 340, idarucizumab). The mean age was 76 (range, 68-83) years, and 57% were men. For 4F-PCC, anticoagulation reversal was 77% (95% CI, 72%-82%; I2 = 55%); all-cause mortality, 26% (95% CI, 20%-32%; I2 = 68%), and thromboembolic events, 8% (95% CI, 5%-12%; I2 = 41%). For AA, anticoagulation reversal was 75% (95% CI, 67%-81%; I2 = 48%); all-cause mortality, 24% (95% CI, 16%-34%; I2 = 73%), and thromboembolic events, 14% (95% CI, 10%-19%; I2 = 16%). Idarucizumab for reversal of dabigatran had an anticoagulation reversal rate of 82% (95% CI, 55%-95%; I2 = 41%), all-cause mortality, 11% (95% CI, 8%-15%, I2 = 0%), and thromboembolic events, 5% (95% CI, 3%-8%; I2 = 0%). A direct retrospective comparison of 4F-PCC and AA showed no differences in anticoagulation reversal, proportional mortality, or thromboembolic events.Conclusions and RelevanceIn the absence of randomized clinical comparison trials, the overall anticoagulation reversal, mortality, and thromboembolic event rates in this systematic review and meta-analysis appeared similar among available DOAC reversal agents for managing ICH. Cost, institutional formulary status, and availability may restrict reversal agent choice, particularly in small community hospitals.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a potentially life threatening severe cutaneous drug reaction. Most patients develop eosinophilia, a rash, a fever, lymphadenopathy and variable visceral organ involvement 2–6 weeks following exposure to the inciting medication. Unlike other severe cutaneous drug reactions, internal organ involvement that leads to high mortality is a unique feature of DRESS syndrome. While the liver is the most common internal organ involved, literally every other visceral organ can be affected in this syndrome. The lesser-known gastrointestinal manifestations of this syndrome include esophagitis, gastritis, enteritis, colitis, pancreatitis and a late autoimmune sequela due to pancreatic injury such as fulminant type 1 diabetes mellitus, autoimmune type 1 diabetes mellitus and type 2 diabetes mellitus. While these entities are less common, they are associated with equally severe complications and adverse patient outcomes. In this review, we synthetize data on these rare manifestations using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The liver, the most common visceral organ involved, has been described as part of DRESS elsewhere and is not included in the scope of this article.

Antiplatelet agents are the standard of practice in the management of atherosclerosis and acute coronary syndrome. In contrast to the available antiplatelet agents, vorapaxar represents a novel mechanism of action. It is an antagonist of the platelet protease-activated receptor-1 and inhibits thrombin-induced and thrombin receptor agonist peptide-induced platelet aggregation. The Thrombin Receptor Antagonist in Secondary Prevention of Atherothrombotic Ischemic Events-Thrombolysis in Myocardial Infarction 50 (TRA 2°P-TIMI 50) trial led to the approval of vorapaxar by the Food and Drug Administration and European Medicines Agency for the reduction of thrombotic cardiovascular events in patients with a history of myocardial infarction (MI) or peripheral arterial disease. TRA 2°P-TIMI 50 trial showed that the use of vorapaxar (2.5 mg once/daily) in addition to standard dual antiplatelet therapy with aspirin and a P2Y12 receptor inhibitor was effective in the secondary prevention of recurrent thrombotic events among patients with previous atherothrombosis, particularly in patients with prior MI; at the expense of an increase in major bleeding. Another recently published Vorapaxar Therapy in Patients With Prior Myocardial Infarction Treated With Newer Generation P2Y12 Receptor Inhibitors Prasugrel and Ticagrelor (VORA-PRATIC) study showed that among post-MI patients treated with potent P2Y12 inhibitors (prasugrel or ticagrelor), vorapaxar reduced platelet-driven global thrombogenicity, an effect that persisted, albeit attenuated, in the absence of aspirin. The current review summarizes an up-to-date literature on pharmacokinetics, pharmacodynamics, and clinical efficacy of vorapaxar and proposes future directions of research.