Catania, June 18, 2024 – A group of researchers from the CoEHAR at the University of Catania, along with international experts from the DiaSmokeFree Working Group, has published a literature review examining the influence of smoking and smoking cessation on the metabolism of antidiabetic drugs. This unique study analyzed how cigarette smoking can alter the metabolic pathways of antidiabetic drugs, with significant implications for the therapeutic efficacy and safety of diabetic patients.
Smoking is a major risk factor for diabetes, impacting not only the onset of the disease but also accelerating its complications. Moreover, the toxic components released during the cigarette combustion process can affect the detoxification mechanisms and metabolism of antidiabetic drugs in the liver. As explained by the researchers, cigarette smoke, composed of two distinct phases—gas and particulate—is a complex mixture of chemicals: many of these substances interact with the biosynthetic functions of the enzymes responsible for xenobiotic metabolism and various transporters, thus influencing drug biotransformation. Therefore, it is hypothesized that smoking, as well as smoking cessation, can interfere with the actions of drugs used in diabetes. This aspect is poorly understood and requires careful investigation.
Researchers from the CoEHAR at the University of Catania, together with international experts from the DiaSmokeFree Working Group, aimed to answer these questions: what could be the effects of smoking cessation on the efficacy and safety of antidiabetic drugs? Could significant changes occur that would require a readjustment of pharmacological treatments?
The working group initiated a detailed review of existing literature, investigating a largely unexplored field.
Key Findings from the Literature Review
PAHs and enzymatic activity: Polycyclic aromatic hydrocarbons (PAHs) present in cigarette smoke induce the activity of cytochrome P450 (CYP) enzymes and uridine diphosphate-glucuronosyltransferases (UGTs), influencing the biotransformation of antidiabetic drugs.
Accelerated metabolism: Cigarette smoke accelerates the metabolism of various antidiabetic drugs, potentially requiring dosage adjustments to maintain therapeutic efficacy.
Post-cessation normalization: Smoking cessation leads to a gradual normalization of hepatic detoxification enzyme systems, significantly affecting the pharmacokinetics of antidiabetic drugs and requiring constant vigilance and possible dosage adjustments by doctors/diabetologists.
Prof. Renato Bernardini, professor of pharmacology at the University of Catania, comments: “The compounds present in cigarette smoke, such as polycyclic aromatic hydrocarbons, can accelerate the metabolism of antidiabetic drugs, requiring dosage adjustments to maintain therapeutic efficacy and reduce the risk of adverse drug reactions. This underscores the importance of constant monitoring of patients during smoking cessation.“
Implications for Clinical Practice
The CoEHAR review provides the first clear information necessary to guide diabetologists in understanding that the path to smoking cessation may also require a readjustment of the dose of drugs used for diabetes. In light of the findings, personalized plans are necessary, which include a thorough knowledge of the interaction mechanisms between smoking and diabetes and possible cessation pathways, to provide concrete help to all those smokers affected by diabetes who want to quit or are succeeding.
“We are explaining how smoking and smoking cessation can influence the metabolism of antidiabetic drugs, with the aim of improving therapeutic management and the health of smoking diabetic patients,” says Dr. Carlo Maria Bellanca, a specialist in pharmacology and clinical toxicology at the Department of Biomedical and Biotechnological Sciences of the University of Catania.
The review identified significant gaps in the existing literature, highlighting the need for further research to improve treatment protocols and health outcomes for this at-risk population. “Quitting smoking is a priority for any smoker, especially for those affected by diabetes. However, quitting smoking represents a significant challenge for diabetic smokers, especially due to undesirable side effects such as weight gain,” explains Prof. Riccardo Polosa, founder of CoEHAR.
