Does glimepiride alter the pharmacokinetics of sildenafil citrate in diabetic nephropathy animals: investigating mechanism of interaction by molecular modeling studies

Pharmacokinetic/Pharmacodynamic Interactions Between Evogliptin and Glimepiride in Healthy Male Subjects

Purpose

Evogliptin, a dipeptidyl peptidase-4 inhibitor, and glimepiride, a sulfonylurea, are used to treat type 2 diabetes mellitus. In this study, we aimed to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) interactions between evogliptin and glimepiride.

Materials and Methods

A randomized, open-label, 3-period, 3-treatment, 2-sequence crossover study was conducted in healthy male subjects. During each period, subjects received multiple doses of evogliptin 5 mg alone (EVO), glimepiride 4 mg alone (GLI), or a combination of the two (EVO+GLI). Serial blood and urine samples were collected 168 and 24 h post dosing, respectively, for PK and PD analyses.

Results

Thirty-four subjects completed the study. The co-administration of evogliptin and glimepiride did not alter their plasma and urine PK profiles. For evogliptin, the geometric mean ratio (GMR) (90% confidence intervals) for the maximum plasma concentrations at steady-state (C_max,ss) and the area under the curve during dosing interval at steady-state (AUC_τ,ss) of EVO+GLI to E were 1.02 (0.98-1.06) and 0.97 (0.95-1.00), respectively. For glimepiride, the corresponding values of EVO+GLI to GLI were 1.08 (1.01-1.17) and 1.08 (1.02-1.14), respectively. All values were within the regulatory bioequivalence criteria of 0.8-1.25. Glucose excursion decreased with the co-administration of evogliptin and glimepiride compared with that observed with the evogliptin or glimepiride monotherapy.

Conclusion

Evogliptin and glimepiride had no PK interactions when co-administered, while the combination therapy showed an additive glucose-lowering effect compared to those of evogliptin or glimepiride monotherapy.

Effect of glimepiride on the pharmacokinetics of teneligliptin in healthy Korean subjects

WHAT IS KNOWN AND OBJECTIVE

Teneligliptin is a DPP-4 inhibitor used for the treatment of type 2 diabetes mellitus, commonly prescribed in combination with glimepiride. Teneligliptin is metabolized by CYP3A4, and glimepiride might be partly metabolized by CYP3A4. The aim of the study was to investigate the possible effect of glimepiride on the pharmacokinetics of teneligliptin in healthy subjects.

METHODS

A repeated dose, open-label, fixed-sequence study was conducted in 26 healthy subjects. All participants were administered 20 mg teneligliptin daily for 6 days. On day 7, 4 mg glimepiride was administered together with 20 mg teneligliptin. Plasma teneligliptin concentrations were measured at a steady state, and its pharmacokinetic characteristics were compared without and with glimepiride.

RESULTS AND DISCUSSION

No statistically significant difference was found in the effect of glimepiride on teneligliptin pharmacokinetics. The steady-state C_max,ss values of teneligliptin without and with glimepiride were 207.01 ng/mL and 202.15 ng/mL, respectively. Its AUC_τ values at steady-state without and with glimepiride were 1527.8 ng · h/mL and 1578.6 ng · h/mL, respectively. The point estimation of geometric mean ratios (GMR) and the 90% confidence interval for both C_max,ss and AUC_τ were within the equivalence range of 0.8-1.25. The results of the present study revealed that glimepiride did not cause pharmacokinetic interaction with teneligliptin in humans.

WHAT IS NEW AND CONCLUSION

Glimepiride did not affect the pharmacokinetic characteristics of teneligliptin in healthy subjects.

Therapeutic efficacy of pentoxifylline on proteinuria and renal progression: an update

Blood pressure control with renin-angiotensin system (RAS) blockade has remained the gold standard for treating patients with proteinuric chronic kidney disease (CKD) up to date. Nevertheless, RAS blockade slows but does not halt the progression of kidney disease, thus highlighting the need to search for additional therapeutic approaches. The nonselective phosphodiesterase (PDE) inhibitor pentoxifylline (PTX) is an old drug that exhibits prominent anti-inflammatory, anti-proliferative and anti-fibrotic activities both in vitro and in vivo. Studies in human subjects have shown that PTX monotherapy decreases urinary protein excretion, and add-on therapy of PTX to background RAS blockade additively reduces proteinuria in patients with CKD of various etiology. More recent studies find that PTX combined with RAS blockade delays the decline of glomerular filtration rate in diabetic patients with mild to moderate CKD, and reduces the risk of end-stage renal disease in diabetic and non-diabetic patients in late stage of CKD with high proteinuria levels. In this review, we update the clinical trial results of PTX as monotherapy, or in conjunction or in comparison with RAS blockade on patients with proteinuria and CKD, and propose a mechanistic scheme explaining the renoprotective activities of this drug.

Pentoxifylline Alleviates Early Brain Injury After Experimental Subarachnoid Hemorrhage in Rats: Possibly via Inhibiting TLR 4/NF-κB Signaling Pathway

Early brain injury (EBI) after subarachnoid hemorrhage (SAH) generally causes significant and lasting damage. Pentoxifylline (PTX), a nonselective phosphodiesterase inhibitor, has shown anti-inflammatory and neuroprotective properties in several brain injury models, but the role of PTX with respect to EBI following SAH remains uncertain. The purpose of this study was to investigate the effects of PTX on EBI after SAH in rats. Adult male Sprauge-Dawley rats were randomly assigned to the sham and SAH groups. PTX (30 or 60 mg/kg) or an equal volume of the administration vehicle (normal saline) was administrated at 30 min intervals following SAH. Neurological scores, brain edema, and neural cell apoptosis were evaluated. In order to explore other mechanisms, changes in the toll-like receptor 4 (TLR4) and the nuclear factor-κB (NF-κB) signaling pathway, in terms of the levels of apoptosis-associated proteins, were also investigated. We found that administration of PTX (60 mg/kg) notably improved neurological function and decreased brain edema at both 24 and 72 h following SAH. Treatment with PTX (60 mg/kg) significantly inhibited the protein expressions of TLR4, NF-κB, MyD88 and the downstream pro-inflammatory cytokines, such as the tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). PTX also significantly reduced neural cell death and BBB permeability. Our observations may be the first time that PTX has been shown to play a neuroprotective role in EBI after SAH, potentially by suppressing the TLR4/NF-κB inflammation-related pathway in the rat brain.

Association of Chemerin and Vascular Endothelial Growth Factor (VEGF) with Diabetic Nephropathy

Background

Diabetic nephropathy (DN) is a common complication of diabetes, caused by diabetic microvascular lesions. The pathogenesis of DN is complicated, involving genetics, physics, chemistry, and environmental factors. Chemerin is a fat cell factor that participates in regulating inflammation. Vascular endothelial growth factor (VEGF) promotes vascular endothelial cell proliferation, differentiation, and angiogenesis. The relationship role of Chemerin and VEGF in DN is not fully understood.

Material/Methods

SD rats were randomly divided into 2 groups: the control group and the DN group. Streptozotocin was used to construct the DN model. Serum creatinine (Scr), blood urea nitrogen (BUN), and urine microalbumin (UAlb) were detected. Real-time PCR and Western blot were used to test Chemerin and VEGF mRNA and protein expression in kidney tissue. ELISA was performed to test TGF-β1, TNF-α, and INF-γ levels. The correlation of Chemerin and VEGF with renal function and inflammatory factors was analyzed.

Results

DN group rats showed obviously increased Scr and BUN levels, and elevated TGF-β1, TNF-α, and INF-γ secretion (P<0.05). Compared with controls, Chemerin and VEGF were clearly overexpressed in the DN group (P<0.05). Chemerin and VEGF expression were positively correlated with inflammatory factors and renal function.

Conclusions

Chemerin and VEGF play important roles in DN by regulating inflammatory factors and renal function. They may be treated as indicators of DN.