The association between warfarin usage and international normalized ratio increase: systematic analysis of FDA Adverse Event Reporting System (FAERS)

Introduction

Elevated international normalized ratio (INR) has been commonly reported as an adverse drug event (ADE) for patients taking warfarin for anticoagulant therapy.

Aim

The purpose of this study was to determine the association between increased INR and the usage of warfarin by using the pharmacovigilance data from the FDA Adverse Event Reporting System (FAERS).

Methods

The ADEs in patients who took warfarin (N = 77,010) were analyzed using FAERS data. Association rule mining was applied to identify warfarin-related ADEs that were most associated with elevated INR (n = 15,091) as well as possible drug-drug interactions (DDIs) associated with increased INR. Lift values were used to identify ADEs that were most commonly reported alongside elevated INR based on the correlation between both item sets. In addition, this study sought to determine if the increased INR risk was influenced by sex, age, temporal distribution, and geographic distribution and were reported as reporting odds ratios (RORs).

Results

The top 5 ADEs most associated with increased INR in patients taking warfarin were decreased hemoglobin (lift = 2.31), drug interactions (lift = 1.88), hematuria (lift = 1.58), asthenia (lift = 1.44), and fall (lift = 1.32). INR risk increased as age increased, with individuals older than 80 having a 63% greater likelihood of elevated INR compared to those younger than 50. Males were 9% more likely to report increased INR as an ADE compared to females. Individuals taking warfarin concomitantly with at least one other drug were 43% more likely to report increased INR. The top 5 most frequently identified DDIs in patients taking warfarin and presenting with elevated INR were acetaminophen (lift = 1.81), ramipril (lift = 1.71), furosemide (lift = 1.64), bisoprolol (lift = 1.58), and simvastatin (lift = 1.58).

Conclusion

The risk of elevated INR increased as patient age increased, particularly among those older than 80. Elevated INR frequently co-presented with decreased hemoglobin, drug interactions, hematuria, asthenia, and fall in patients taking warfarin. This effect may be less pronounced in women due to the procoagulatory effects of estrogen signaling. Multiple possible DDIs were identified, including acetaminophen, ramipril, and furosemide.

The so-called anterior meningeal artery: an anatomic study for treatment modalities

SUMMARY

The so called anterior meningeal artery (AMA) is a branch of the vertebral artery (VA), which had been interpreted as a supplying vessel of the dura in the foramen magnum and upper cervical level. In this study, we examined the anatomy of this artery and relationships to its surrounding structures for treatment modalities. With the aid of magnification, five adult cadaveric head and neck complex and five cervical spines were examined after perfusion of the vessels with colored silicone. The AMA arose from the VA between the C2 and C3 level, and passed medially through the intrervertebral foramen anterior to the dural sheath of the third cervical nerve root. It ran upwards dorsal to the deep layer of the posterior longitudinal ligament (PLL) with anterior internal vertebral venous plexus. Rostrally, it formed an arcade above the apex of the odontoid process with its contralateral mate. The AMA gave off several tiny branches to the deep layer of the PLL, ligaments and soft tissues above the apex of the odontoid process, and vertebral bodies of the axis. At the level of the foramen magnum, it ended in several small twigs to the dura. Anastomoses between the AMA system and adjacent vessels were observed. One was directed through the hypoglossal canal to the ascending pharyngeal artery and the other was with the V3 segment of the VA. The origin and course of the two AMA, and anastomoses were symmetric. Although the AMA feeds the ventral dura of the foramen magnum, the perfusion area is larger than its name suggests, including the bony and ligamentous structures in the craniovertebral junction. Anatomical knowledge of the AMA, including its anastomoses and layer relationships to the surrounding structures, may help to perform treatment modalities in this region rationally.

Transitional cell carcinoma of the ureter and struvite calculi

CONTEXT

The association of primary carcinoma of the ureter and lithiasis is extremely rare. We report a rare case of a primary carcinoma of the ureter with corariform calculus.

CASE REPORT

60-year-old phaeodermal female, reported a history of right-side nephritic colic, hyperthermia and pyuria during the past 20 years and had received treatment for urinary infections a number of times. The first clinical presentation was related to lithiasis and the tumor had not been shown up by excretory urography, cystoscopy or ultrasonography. Two months after the calculus had been eliminated, the patient began to have serious symptoms and a grade III transitional cell carcinoma of the ureter was discovered. Total nephroureterectomy and M.V.A.C. (Methotrexate + Vinblastina + Doxo Rubicina + Cisplatina) chemotherapy were tried unsuccessfully. In this report we emphasize the diagnostic difficulty caused by the concomitant presence of the two pathologies. In our opinion, the rapid evolution in this case is directly related to the high grade of the tumor.

Penis wound by scorpion sting

CONTEXT

The majority of scorpion stings are oligosymptomatic, occurring mainly on the hands and feet. Fatality is rare.

CASE REPORT

A 33-year old man suffered a severe sting on his penis from a scorpion of the species Tytius trivittatus. Alcohol and salt were used without success in an effort to relieve pain. Medical assistance was sought 4 hours after the event, at which time diffuse erythema, edema and punctiform injury on the glans penis were observed, with no systemic manifestation. Intravenous meperidine was administered with immediate relief of the pain. The local signs disappeared within 48 hours, with the patient remaining asymptomatic.

A new tick-borne encephalitis-like virus infecting New England deer ticks, Ixodes dammini

To determine if eastern North American Ixodes dammini, like related ticks in Eurasia, maintain tick-borne encephalitis group viruses, we analyzed ticks collected from sites where the agent of Lyme disease is zoonotic. Two viral isolates were obtained by inoculating mice with homogenates from tick salivary glands. The virus, which was described by reverse transcriptase polymerase chain reaction and direct sequencing of the amplification products, was similar to, but distinct from, Powassan virus and is provisionally named "deer tick virus." Enzootic tick-borne encephalitis group viruses accompany the agents of Lyme disease, babesiosis, and granulocytic ehrlichiosis in a Holarctic assemblage of emergent deer tick pathogens.