Severe leucopenia associated with Sitagliptin use

SARS-CoV-2 and diabetes: A potential therapeutic effect of dipeptidyl peptidase 4 inhibitors in diabetic patients diagnosed with COVID-19

COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 and has become an urgent economic and health challenge. Dipeptidyl peptidase 4 (DPP4), also mentioned as a cluster of differentiation 26 (CD26) is a serine exopeptidase found in two arrangements: a soluble form (sDPP-4) and a plasma membrane-bound form. Because other coronaviruses enter the cells by binding to DPP-4, it has been speculated that DPP-4 inhibitors may exert activity against COVID-19. Therefore, this review aimed to summarize the potential therapeutic effect of dipeptidyl peptidase 4 inhibitors in diabetic patients diagnosed with COVID-19. To include different studies, publications related to Dipeptidyl peptidase-4 inhibitor use and clinical outcomes from COVID-19 were searched from the databases such as Web of Science, PubMed, Medline, Elsevier, Google Scholar, and SCOPUS, via English key terms. A direct engrossment of DPP4 in COVID-19 needs to be elucidated, there is also evidence confirming that DPP4 inhibitors exert anti-fibrotic and modulate inflammation activity. Thus, the use of DPP-4 inhibitors could reduce mortality due to COVID-19 or improve the progression of COVID-19; this evidence may support the management of diabetic patients diagnosed with COVID-19; however more well-designed investigation is urgently required.

DPP4 and ACE2 in Diabetes and COVID-19: Therapeutic Targets for Cardiovascular Complications?

COVID-19 outbreak, caused by severe acute respiratory syndrome (SARS)-CoV-2 coronavirus has become an urgent health and economic challenge. Diabetes is a risk factor for severity and mortality of COVID-19. Recent studies support that COVID-19 has effects beyond the respiratory tract, with vascular complications arising as relevant factors worsening its prognosis, then making patients with previous vascular disease more prone to severity or fatal outcome. Angiotensin-II converting enzime-2 (ACE2) has been proposed as preferred receptor for SARS-CoV-2 host infection, yet specific proteins participating in the virus entry are not fully known. SARS-CoV-2 might use other co-receptor or auxiliary proteins allowing virus infection. In silico experiments proposed that SARS-CoV-2 might bind dipeptidyl peptidase 4 (DPP4/CD26), which was established previously as receptor for MERS-CoV. The renin-angiotensin-aldosterone system (RAAS) component ACE2 and DPP4 are proteins dysregulated in diabetes. Imbalance of the RAAS and direct effect of soluble DPP4 exert deleterious vascular effects. We hypothesize that diabetic patients might be more affected by COVID-19 due to increased presence ACE2 and DPP4 mediating infection and contributing to a compromised vasculature. Here, we discuss the role of ACE2 and DPP4 as relevant factors linking the risk of SARS-CoV-2 infection and severity of COVID-19 in diabetic patients and present an outlook on therapeutic potential of current drugs targeted against RAAS and DPP4 to treat or prevent COVID-19-derived vascular complications. Diabetes affects more than 400 million people worldwide, thus better understanding of how they are affected by COVID-19 holds an important benefit to fight against this disease with pandemic proportions.

SARS-CoV-2 and DPP4 inhibition: Is it time to pray for Janus Bifrons?

Diabetes could be a risk factor for severity and mortality in patients with coronavirus disease 2019 COVID-19. It has been hypothesized that DPP4 inhibition, a therapy currently available for type 2 diabetes, might represent a target for decreasing the risk of the acute respiratory complications of the COVID-19 infection but (1) lack of demonstration of SARS-CoV2 binding to DPP4 (2) possible protective role of sDPP4 in Middle East respiratory Syndrome (MERS-CoV) (3) demonstrated inhibition and downregulation of DPP4 by HIV1 and MERS-CoV and (4) not exclusive role of the receptor binding in tropism of the Coronavirus family, support that DPP4 inhibition at present doesn't represent a plausible approach to mitigate COVID-19.

DPP-4 inhibitors: a patent review (2012 - 2014)

INTRODUCTION

Dipeptidyl peptidase 4 (DPP-4) is a serine protease, which catalyzes the hydrolytic process of the amide bond X-Ala or X-Pro at the N-terminus of peptides. This enzyme is involved in the degradation of two incretin hormones glucagon-like peptide-1 and glucose-dependent-insulinotropic polypeptide, which increase the production and release of insulin. Therefore, DPP-4 inhibitors are considered as one of the well-established therapies available for type 2 diabetes mellitus.

AREAS COVERED

In this review, the authors report all the patents related to DPP-4 inhibitors from 2012 to 2014. The chemical-related patents have been divided in three general families: i) peptidomimetics; ii) peptides; and iii) non-peptidomimetics compounds. The third group is the most consistent; thus the patents have been further divided on the basis of the chemical structure. In the last section, we briefly discuss the patents containing the formulations or associations of DPP-4 inhibitors with other drugs.

EXPERT OPINION

In the last few years, the research on DPP-4 inhibitors has significantly grown leading to the development of heterocyclic scaffolds and non-peptidomimetic structures. Unfortunately, these compounds are not immune from side effects associated with the inhibition of other substrates, indicating that DPP-4 inhibitors are likely multi-target drugs. Therefore, their potential multi-target effects require more attention in clinical practice, even if at this moment, all the patents are focused only on diabetes.

The pharmacokinetic considerations and adverse effects of DPP-4 inhibitors [corrected]

INTRODUCTION

Dipeptidyl-peptidase-4 (DPP-4) inhibitors are a class of anti-hyperglycemic agents with proven efficacy in patients with type 2 diabetes mellitus (T2DM).

AREAS COVERED

This review considers the pharmacokinetic profile, adverse effects and drug interactions of DPP-4 inhibitors. DPP-4 inhibitors have certain differences in their structure, metabolism, route of elimination and selectivity for DPP-4 over structurally related enzymes, such as DPP-8/DPP-9. They have a low potential for drug interactions, with the exception of saxagliptin that is largely metabolized by cytochrome CYP3A4/A5. Reports of pancreatitis and pancreatic cancer have raised concerns regarding the safety of DPP-4 inhibitors and are under investigation. Post-marketing surveillance has revealed less common adverse effects, especially a number of skin- and immune-related adverse effects. These issues are covered in the present review.

EXPERT OPINION

DPP-4 inhibitors are useful and efficient drugs. DPP-4 inhibitors have similar mechanism of action and similar efficacy. However, DPP-4 inhibitors have certain differences in their pharmacokinetic properties that may be associated with different clinical effects and adverse event profiles. Although clinical trials indicated a favorable safety profile, post-marketing reports revealed certain safety aspects that need further investigation. Certainly, more research is needed to clarify if the differences among DPP-4 inhibitors could lead to a different clinical and safety profile.

Dipeptidyl peptidase-4 inhibitors: multitarget drugs, not only antidiabetes drugs

Dipeptidyl peptidase (DPP)-4 inhibitors are a new class of antidiabetic agents that reduce blood glucose by preventing the degradation of the endogenous incretin hormones glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide. Protection by DPP-4 inhibitors of β-cell function has been demonstrated in patients with type 2 diabetes. Because DPP-4 is an enzyme widely expressed in humans, DPP-4 inhibitors are speculated to be multitarget agents. However, other potential therapeutic benefits of DPP-4 inhibitors remain unknown. Recently, some therapeutic effects of DPP-4 inhibitors, such as immune regulation, cardiovascular protection, and anti-inflammatory effects, have been observed. This article provides a systematic and comprehensive review of current research into the newly found effects and mechanism of action of DPP-4 inhibitors in a therapeutic context.

Efficacy of sitagliptin when added to ongoing therapy in korean subjects with type 2 diabetes mellitus

BACKGROUND

To evaluate the clinical efficacy of sitagliptin for reducing plasma glucose levels in Korean subjects with type 2 diabetes mellitus during a 14-week treatment period.

METHODS

Our study design involved the addition of 100 mg sitagliptin once-daily to three ongoing combination therapy regimens and changing from glimepiride and metformin to sitagliptin and metformin.

RESULTS

The addition of sitagliptin 100 mg/day produced a statistically significant reduction in mean HbA1c level (mean HbA1c reduction of 0.99±0.85%, P<0.01). In the group taking a combination of sitagliptin and metformin (n=143, initial mean HbA1c level=7.48%), the reductions in HbA1c, 2-hour postprandial glucose, and fasting glucose levels were 0.72±0.76% (P<0.01), 47±65 mg/dL (P<0.01), and 15±44 mg/dL (P<0.01), respectively. In the group taking a combination of sitagliptin, glimepiride, and metformin (n=125, initial mean HbA1c level=8.42%), the reductions in HbA1c, 2-hour postprandial glucose, and fasting glucose levels were 1.09±0.86% (P<0.01), 62±64 mg/dL (P<0.01), and 31±45 mg/dL (P<0.01), respectively. In the group taking a combination of sitagliptin, glimepiride, metformin, and α-glucosidase inhibitor (n=63, initial mean HbA1c level=9.19%), the reductions in HbA1c, 2-hour postprandial glucose, and fasting glucose levels were 1.27±0.70% (P<0.01), 72±65 mg/dL (P<0.01), and 35±51 mg/dL (P<0.01), respectively. In the group that had previous hypoglycemic events and that changed from glimepiride to sitagliptin, HbA1c level did not change but fasting glucose increased significantly (14±29 mg/dL, P<0.01).

CONCLUSION

Sitagliptin combination therapy for 14 weeks significantly improved glycemic control and was well-tolerated in Korean subjects with type 2 diabetes mellitus.