Long-acting insulin analogue
Insulin Glargine and smoking: how tobacco affects the medication
Tobacco smoking is one of the most underappreciated drug-drug interactions in chronic medication. Compounds in tobacco smoke induce hepatic enzymes (especially CYP1A2) and can shift the plasma concentration of many medications, including Insulin Glargine (Insulin Glargine), enough to matter clinically at 100 IU/mL.
How smoking affects Insulin Glargine
Polycyclic aromatic hydrocarbons in tobacco smoke induce CYP1A2 and to a lesser extent other CYP enzymes. For medications metabolised primarily by CYP1A2, smokers can have plasma levels 30–50% lower than non-smokers at the same dose. Whether Insulin Glargine is affected depends on its specific metabolic pathway. Insulin glargine binds the insulin receptor with similar affinity to human insulin, activating intracellular signalling that increases glucose uptake in muscle and adipose tissue, suppresses hepatic g…
Practical guidance
According to the prescribing information for Insulin Glargine, smoking status should be disclosed at every dose review of Insulin Glargine. Stopping smoking can paradoxically raise plasma levels of CYP1A2-metabolised medications enough to cause new-onset side effects within days, and may require a temporary dose reduction. The 100 IU/mL starting strength assumed in the prescribing information is usually for non-smokers.
Frequently asked questions
Does smoking change how Insulin Glargine works? ▾
For medications metabolised by CYP1A2, yes — smokers may need higher doses or have reduced effect at standard 100 IU/mL. Whether Insulin Glargine specifically is affected depends on whether Insulin Glargine uses CYP1A2. The prescribing information notes any documented interaction.
Will I need to adjust Insulin Glargine if I quit smoking? ▾
Possibly, if Insulin Glargine is one of the medications affected by CYP1A2 induction. Stopping smoking restores CYP1A2 to normal within days, raising plasma levels and potentially causing side effects. Discuss the timing of any dose adjustment with the prescriber when planning to quit.
Products containing Insulin Glargine
More on Insulin Glargine
- With alcoholInsulin Glargine and alcohol — is it safe to drink?
- With foodShould Insulin Glargine be taken with food?
- Side effectsInsulin Glargine side effects: common, rare and warning signs
- Dosage guideInsulin Glargine dosage guide: how much to take and when
- OnsetHow fast does Insulin Glargine start working?
- DurationHow long does Insulin Glargine last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.