Different effects of dihydropyridine calcium channel antagonists on CYP3A4 enzyme of human liver microsomes

Inhibitory effects of nimodipine, nitrendipine and felodipine on tamoxifen metabolism and molecular docking

Tamoxifen, a selective estrogen receptor modulator (SERM) used in breast cancer therapy, requires metabolic activation by CYP3A4 to exert its biological effects. This study evaluated the effects of calcium channel blockers nimodipine, nitrendipine and felodipine on tamoxifen metabolism by studying their interactions with tamoxifen in vitro and in vivo. Rat liver microsomes (RLM) and human liver microsomes (HLM) were used in this study to evaluate the inhibitory potential of nimodipine, nitrendipine and felodipine on tamoxifen metabolism in vitro. A total of 28 cardiovascular drugs, including calcium channel blockers, were screened in an RLM incubation system in vitro. In RLM, nimodipine, nitrendipine and felodipine had half-maximum inhibitory concentration (IC50) values of 5.55 µM, 11.86 µM and 7.71 µM, respectively. In HLM, the IC50 values were increased to 20.38 µM, 30.06 µM, and 44.45 µM for nimodipine, nitrendipine and felodipine, respectively. The kinetic assays indicated that nimodipine and felodipine inhibited the metabolism of tamoxifen in a competitive way, whereas nitrendipine showed non-competitive inhibition in RLM. However, felodipine exhibited non-competitive inhibition, and nimodipine and nitrendipine showed competitive inhibition in HLM. Pharmacokinetic studies in rats revealed that pretreatment with nimodipine and nitrendipine significantly increased the systemic exposure of tamoxifen, as demonstrated by increasing the area under the curve (AUC), the maximum concentration (Cmax) and decreasing the clearance (CLz/F). Finally, molecular docking studies supported these findings, showing potential interactions at the active site of CYP3A4. These results suggested the necessity for careful monitoring and possible dose adjustments of tamoxifen when co-administered with calcium channel blockers in clinic.

Evaluation of drug interaction between cyclosporine and lercanidipine: a descriptive study

OBJECTIVES

Cyclosporine is an immunosuppressive drug with a high potential for drug interactions that is frequently used in renal transplant patients. The purpose of this study was to assess the change in cyclosporine concentration in patients taking cyclosporine and lercanidipine concurrently.

METHODS

The potential drug interactions in renal transplant patients who received lercanidipine and cyclosporine concurrently in a university hospital between January 2008 and January 2018 were evaluated retrospectively. Patients had renal transplantation from deceased donors or living related donors. The Drug Interaction Probability Scale (DIPS) criteria were used to assess the causality of cyclosporine and lercanidipine drug interaction.

RESULTS

The study included six renal transplant patients. The median cyclosporine concentration before lercanidipine use was 325 ng/mL (min-max 101-356) and 592.5 ng/mL (min-max 198-799) thereafter (p=0.028). Serum creatinine and proteinuria levels did not change significantly during lercanidipine treatment (p=0.686 and p=0.116, respectively). According to the DIPS evaluation, cyclosporine and lercanidipine interaction was classified as "possible (score 3)".

CONCLUSIONS

Concomitant use of cyclosporine and lercanidipine increases the concentration of cyclosporine, which may result in side effects during effective treatment in renal transplant patients. Therefore, cyclosporine concentrations should definitely be monitored while patients are taking lercanidipine.

Toward Second-Generation Cardiomyogenic and Anti-cardiofibrotic 1,4-Dihydropyridine-Class TGFβ Inhibitors

Innovative therapeutic modalities for pharmacological intervention of transforming growth factor β (TGFβ)-dependent diseases are of great value. b-Annelated 1,4-dihydropyridines (DHPs) might be such a class, as they induce TGFβ receptor type II degradation. However, intrinsic drawbacks are associated with this compound class and were systematically addressed in the presented study. It was possible to install polar functionalities and bioisosteric moieties at distinct sites of the molecules while maintaining TGFβ-inhibitory activities. The introduction of a 2-amino group or 7-N-alkyl modification proved to be successful strategies. Aqueous solubility was improved by up to seven-fold at pH 7.4 and 200-fold at pH 3 relative to the parent ethyl 4-(biphenyl-4-yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate. The therapeutic potential of the presented DHPs was further underscored in view of a potential dual mode of action: The differentiation of committed human iPSC-derived cardiac progenitor cells (CPCs) was potently stimulated, and the rescue of cardiac fibrosis phenotypes was observed in engineered heart tissue (EHT) constructs.

Pharmacokinetic drug-drug interaction of calcium channel blockers with cyclosporine in hematopoietic stem cell transplant children

BACKGROUND

Cyclosporine (CsA) is frequently responsible for hypertension in bone marrow transplant children. Calcium channel blockers (CCBs) are considered to be the best treatment for CsA-induced hypertension, but they may alter the exposure and the effect of CsA by inhibiting the CYP3A4 pathway of CsA metabolism or P-gp. However, the inhibitory effect on CYP3A4 may vary among CCBs.

METHODS

This study aimed to quantify the pharmacokinetic drug-drug interaction between CsA and nicardipine, amlodipine, and lacidipine. In all, 51 children who received CsA and CCB concomitantly were included.

RESULTS

Dose-normalized CsA trough blood concentrations significantly increased in patients treated with nicardipine and amlodipine, whereas they remained stable in patients treated with lacidipine.

CONCLUSIONS

Because lacidipine appears to have no effect on CsA exposure, it may be the best option among CCBs for treating high blood pressure caused by CsA in children.