levels of many of the quinolones
can be reduced by aluminium/magnesium antacids
. Calcium compounds interact to a lesser extent, and bismuth compounds only minimally.
As a very broad rule-of-thumb, the quinolones
should be taken at least 2 hours before and not less than 4 to 6 hours after aluminium/magnesium antacids
. The interaction with calcium compounds is variable, and some quinolones
may not interact, but in the absence of direct information a 2-hour separation errs on the side of caution. The interaction with bismuth is minimal and no action is likely to be needed. The H2-receptor antagonists
and the proton pump inhibitors do not interact and may therefore be suitable alternatives.