The recommended dose at that time was decreased by a factor of two because of the improved bioavailability. Thus drugs which are extensively metabolized will be metabolized in the liver during absorption. Both these drugs and many others are extensively metabolized in the liver. I motility can effect drug absorption. Often patient instructions include a direction to take with food or take on an empty stomach.
Absorption is slower with food for tetracyclines and penicillins, etc.
However, for propranolol bioavailability is higher after food, and for griseofulvin absorption is higher after a fatty meal. Local effect - Antibiotics may kill normal gut flora and allow overgrowth of fungal varieties. Thus, antifungal agent may be included with an antibiotic. Unconscious patient - Patient must be able to swallow solid dosage forms. Liquids may be given by tube.