Lantus with antibiotics: interactions and safety

Antibiotic courses are common, short-term and often combined with chronic medications such as Lantus (Insulin Glargine). Most antibiotics do not interfere meaningfully with Insulin Glargine at 100 IU/mL, but a few classes do, and a small number of combinations are best avoided.

Common antibiotic interactions

Macrolides (clarithromycin, erythromycin) and certain antifungals can inhibit hepatic metabolism (CYP3A4) and raise plasma levels of many medications including some Diabetes Treatment agents. Rifampicin has the opposite effect, accelerating metabolism. Most penicillins, cephalosporins, fluoroquinolones and tetracyclines have no clinically meaningful interaction with Insulin Glargine at 100 IU/mL.

Practical guidance

According to the prescribing information for Insulin Glargine, an antibiotic course should be reviewed by the prescriber or pharmacist for known interactions before Lantus is co-administered. Adjusted 100 IU/mL dosing or temporary substitution is sometimes preferred for the duration of the antibiotic course.

Frequently asked questions

Can I take Lantus during an antibiotic course? ▾

For most common antibiotics, yes. A few classes — notably macrolides and azole antifungals — alter how Insulin Glargine is metabolised and may need a temporary 100 IU/mL adjustment. The prescribing pharmacist should review any new antibiotic against the existing Lantus regimen.

Will antibiotics make Lantus stop working? ▾

Most antibiotics do not affect Lantus efficacy. Rifampicin and a few others can lower Insulin Glargine levels and reduce effect; in those cases the prescriber may adjust the dose during and shortly after the antibiotic course.

More on Lantus

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