Preventing Multidrug-Resistant TB with Levofloxacin

Although rifampin-resistant or multidrug (isoniazid and rifampin)–resistant (MDR) tuberculosis (TB) is uncommon in the U.S., it occurs worldwide in 400,000 people each year. Current preventive treatments for drug-sensitive latent TB (including rifamycins, isoniazid, or both) are not anticipated to be effective at preventing drug-resistant TB. Now, investigators report results of two randomized trials evaluating whether levofloxacin prevents TB in people exposed to drug-resistant TB.

In the VQUIN-MDR trial conducted in Vietnam, household contacts of people with rifampin-resistant or MDR TB were randomized to receive levofloxacin or placebo for 6 months. Contacts were eligible if they had evidence of TB infection (based on tuberculin skin test…