Antiplatelet, anticoagulant or both? A tool for pharmacists

A retrospective study of antithrombotic therapy use in an outpatient haemodialysis unit

WHAT IS KNOWN AND OBJECTIVE

Patients on haemodialysis (HD) are at increased risk of both bleeding and thrombotic events, due to comorbidities and nature of dialysis treatment. However, there is a lack of research on evidence-based treatment strategies and prescribing patterns for antithrombotic therapies (ATT) in this population. To characterize ATT use and its main indications in an outpatient HD unit.

METHODS

A single-centre retrospective chart review was conducted in a Toronto outpatient HD unit (n = 329). Medical histories, number of ATTs and corresponding indications were collected from adult patients prescribed at least one ATT from 1 October 2019 to 31 December 2019, inclusive.

RESULTS AND DISCUSSION

Of 329 patients in the unit, a total of 135 (41%) patients were on at least one ATT. Of these 135 patients, 80% were on monotherapy (55% antiplatelet, 25.1% anticoagulant), 12.6% were on dual antiplatelet therapy (DAPT), and 7.4% were on a antiplatelet and anticoagulant combination. Primary indications for ATT in our cohort were coronary artery disease (CAD; 55%), atrial fibrillation (18.5%) and venous thromboembolism (VTE; 17%). Described ATT use was in-line with current clinical guidelines. Monotherapy was primarily used in our HD cohort, whereas few patients were on dual therapy. Low-dose aspirin was the most common antiplatelet prescribed for secondary prevention of cardiovascular events. Warfarin monotherapy was primarily indicated for VTE, and DAPT aspirin/clopidogrel was the most commonly prescribed for CAD.

WHAT IS NEW AND CONCLUSION

Our characterization of ATT use in this HD cohort demonstrates that ATT is often prescribed for a number of different CVD reasons. Overlapping and confounding indications for prescribing ATTs, lack of randomized controlled trials and unclear clinical guidelines mean that individualized risk-benefit assessments for ATT use are still needed to provide care for these high-risk patients. More research to address the safety and efficacy of ATTs is warranted to develop more robust evidence-based treatment guidelines for the HD population.

Synthesis of 3,3-dimethyl-6-oxopyrano[3,4-c]pyridines and their antiplatelet and vasodilatory activity

OBJECTIVES

Both pyridine and pyrano derivatives have been previously shown to possess biologically relevant activity. In this study, we report the incorporation of these two scaffolds into one molecule.

METHODS

The designed 3,3-dimethyl-6-oxopyrano[3,4-c]pyridines were synthesized by the acylation of enamine under Stork conditions followed by condensation of formed β-diketones with 2-cyanoacetamide. The structures of these compounds were confirmed by using a wide spectrum of physico-chemical methods. Their antiplatelet, anticoagulant and vasodilatory activity together with toxicity were evaluated.

KEY FINDINGS

A series of 6-oxopyrano[3,4-c]pyridines 3a-j was obtained. Four of these compounds were reported for the first time. None of the tested compounds demonstrated anticoagulant effect but 8-methyl derivative (3a) was a potent antiplatelet compound with IC50 numerically twice as low as the clinically used acetylsalicylic acid. A series of further mechanistic tests showed that 3a interferes with calcium signaling. The compound is also not toxic and in addition possesses vasodilatory activity as well.

CONCLUSIONS

Compound 3a is a promising inhibitor of platelet aggregation, whose mechanism of action should be studied in detail.