Pharmacokinetic interaction between telithromycin and metformin in diabetes mellitus rats

Inhibitory Mechanisms of Lekethromycin in Dog Liver Cytochrome P450 Enzymes Based on UPLC-MS/MS Cocktail Method

Lekethromycin (LKMS) is a synthetic macrolide compound derivative intended for use as a veterinary medicine. Since there have been no in vitro studies evaluating its potential for drug-drug interactions related to cytochrome P450 (CYP450) enzymes, the effect of the inhibitory mechanisms of LKMS on CYP450 enzymes is still unclear. Thus, this study aimed to evaluate the inhibitory effects of LKMS on dog CYP450 enzymes. A cocktail approach using ultra-performance liquid chromatography-tandem mass spectrometry was conducted to investigate the inhibitory effect of LKMS on canine CYP450 enzymes. Typical probe substrates of phenacetin, coumarin, bupropion, tolbutamide, dextromethorphan, chlorzoxazone, and testosterone were used for CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2D6, CYP2E1, and CYP3A4, respectively. This study showed that LKMS might not be a time-dependent inhibitor. LKMS inhibited CYP2A6, CYP2B6, and CYP2D6 via mixed inhibition. LKMS exhibited mixed-type inhibition against the activity of CYP2A6 with an inhibition constant (Ki) value of 135.6 μΜ. LKMS inhibited CYP2B6 in a mixed way, with Ki values of 59.44 μM. A phenotyping study based on an inhibition assay indicated that CYP2D6 contributes to the biotransformation of LKMS. A mixed inhibition of CYP2D6 with Ki values of 64.87 μM was also observed. Given that this study was performed in vitro, further in vivo studies should be conducted to identify the interaction between LKMS and canine CYP450 enzymes to provide data support for the clinical application of LKMS and the avoidance of adverse interactions between other drugs.

A Review: Effects of Macrolides on CYP450 Enzymes

As a kind of haemoglobin, cytochrome P450 enzymes (CYP450) participate in the metabolism of many substances, including endogenous substances, exogenous substances and drugs. It is estimated that 60% of common prescription drugs require bioconversion through CYP450. The influence of macrolides on CYP450 contributes to the metabolism and drug-drug interactions (DDIs) of macrolides. At present, most studies on the effects of macrolides on CYP450 are focused on CYP3A, but a few exist on other enzymes and drug combinations, such as telithromycin, which can decrease the activity of hepatic CYP1A2 and CYP3A2. This article summarizes some published applications of the influence of macrolides on CYP450 and the DDIs of macrolides caused by CYP450. And the article may subsequently guide the rational use of drugs in clinical trials. To a certain extent, poisoning caused by adverse drug interactions can be avoided. Unreasonable use of macrolide antibiotics may enable the presence of residue of macrolide antibiotics in animal-origin food. It is unhealthy for people to eat food with macrolide antibiotic residues. So it is of great significance to guarantee food safety and protect the health of consumers by the rational use of macrolides. This review gives a detailed description of the influence of macrolides on CYP450 and the DDIs of macrolides caused by CYP450. Moreover, it offers a perspective for researchers to further explore in this area.

Use of bedaquiline and delamanid in diabetes patients: clinical and pharmacological considerations

Antituberculosis (anti-TB) treatment may be affected by both diabetes and hypoglycemic agents in patients with these 2 comorbidities. However, data supporting this conclusion relate only to standard anti-TB therapies. Sirturo^® (bedaquiline) and Deltyba^® (delamanid), novel drugs for multidrug-resistant tuberculosis (MDR-TB), are recommended for diabetes patients when another effective treatment regimen cannot be provided. Currently, there are no clinical data related to the use of these agents in diabetes patients. Possible alterations in the pharmacokinetics of these novel drugs induced by changes in subcutaneous adipose blood flow, gastric emptying, or nephropathy in diabetes patients, and possible drug–drug interactions with hypoglycemic agents, are of special interest, since the efficacy of bedaquiline and delamanid is concentration dependent. Moreover, it is of fundamental importance to avoid possible additive or synergistic effects of adverse drug reactions in this already vulnerable patient group. We reviewed clinical particularities related to the use of bedaquiline and delamanid in patients with type 1 and 2 diabetes mellitus (DM), as well as pharmacological aspects of the concurrent use of these agents with oral and injectable hypoglycemic agents. Bedaquiline shares liver metabolic pathways with several oral hypoglycemic agents, whereas delamanid may compete with several oral hypoglycemic agents and insulin analogs at protein-binding sites. Special concern exists regarding the use of bedaquiline and delamanid in diabetes patients aged >65 years and patients with severe renal or hepatic impairment or electrolyte disturbances. Concurrent use of bedaquiline and delamanid with insulin analogs, and other hypoglycemic agents that prolong the heart rate-corrected QT interval, such as sulfonylureas and glinides, may enhance this adverse reaction. Hepatic-related adverse reactions may develop more frequently when these drugs are combined with thiazolidinediones and acarbose. Data from Phase III and postmarketing studies are needed to elucidate the effect of DM and hypoglycemic agents on bedaquiline and delamanid effects in MDR-TB patients.