I've read on this publication that every drug that induces CYP3A can reduce the effectiveness of clarithromycin. Clarithromycin inhibits CYP3A.
But it does not say anything about the opposite situation: does a low concentration of CYP3A increase the effect of clarithromycin?
This research shows how DHA can inhibit CYP3A.
Now the final question is: does a high concentration of DHA increase the effect of clarithromycin?