Drug Interaction Report

GENERALLY AVOID: Antibiotics may interfere with the therapeutic effects of oral fecal microbiota, which contains live bacterial spores. The mechanism may be related to the antibiotic inactivating the bacterial spores or reducing bacterial replication. However, the clinical significance of this interaction has not been established.

MANAGEMENT: Concomitant use of oral fecal microbiota spores with antibiotics should generally be avoided. The manufacturer of the oral formulation of fecal microbiota recommends that treatment commence two to four days after completing antibiotic treatment for Clostridium difficile infection.

ADJUST DOSING INTERVAL: There are no data regarding the effects of concurrent administration of oral fecal microbiota spores with food.

MANAGEMENT: The manufacturer of the oral formulation of fecal microbiota recommends that patients should have no food or drink except for a small amount of water for at least 8 hours prior to the first dose of fecal microbiota spores. The second and third doses of fecal microbiota spores should be taken on an empty stomach prior to the first meal of the day.

Grapefruit juice may delay the gastrointestinal absorption of clarithromycin but does not appear to affect the overall extent of absorption or inhibit the metabolism of clarithromycin. The mechanism of interaction is unknown but may be related to competition for intestinal CYP450 3A4 and/or absorptive sites. In an open-label, randomized, crossover study consisting of 12 healthy subjects, coadministration with grapefruit juice increased the time to reach peak plasma concentration (Tmax) of both clarithromycin and 14-hydroxyclarithromycin (the active metabolite) by 80% and 104%, respectively, compared to water. Other pharmacokinetic parameters were not significantly altered. This interaction is unlikely to be of clinical significance.