Clarithromycin and Lopinavir and ritonavir interaction
Clarithromycin and Lopinavir and ritonavir: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Clarithromycin label · effective 2026-01-01
Doses of clarithromycin greater than 1000 mg per day should not be co-administered with protease inhibitors.
Ritonavir (in patients with decreased renal function) Ritonavir: Since concentrations of 14-OH clarithromycin are significantly reduced when clarithromycin is co-administered with ritonavir, alternative antibacterial therapy should be considered for indications other than infections due to Mycobacterium avium [see Pharmacokinetics ( 12.3 )] .
Saquinavir (in patients with decreased renal function) Saquinavir: When saquinavir is co-administered with ritonavir, consideration should be given to the potential effects of ritonavir on clarithromycin (refer to ritonavir above) [see Pharmacokinetics ( 12.3 )] .
Miscellaneous Cytochrome P450 Inducers: Efavirenz Nevirapine Rifampicin Rifabutin Rifapentine Use With Caution Inducers of CYP3A enzymes, such as efavirenz, nevirapine, rifampicin, rifabutin, and rifapentine will increase the metabolism of clarithromycin, thus decreasing plasma concentrations of clarithromycin, while increasing those of 14-OH-clarithromycin.
Alternative antibacterial treatment should be considered when treating patients receiving inducers of CYP3A.
From the Lopinavir and ritonavir (Kaletra) label · effective 2026-07-23
Avoid use in patients with congenital long QT syndrome, those with hypokalemia, and with other drugs that prolong the QT interval.
Anti-infective: clarithromycin ↑ clarithromycin For patients with renal impairment, adjust clarithromycin dose as follows: For patients on KALETRA with CL CR 30 to 60 mL/min the dose of clarithromycin should be reduced by 50%.
For patients on KALETRA with CL CR < 30 mL/min the dose of clarithromycin should be decreased by 75%.
Potential for KALETRA to Affect Other Drugs Lopinavir/ritonavir is an inhibitor of CYP3A and may increase plasma concentrations of agents that are primarily metabolized by CYP3A.
Although not observed in the KALETRA/ketoconazole drug interaction study, co-administration of KALETRA and other drugs that inhibit CYP3A may increase lopinavir plasma concentrations.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.