Question

Why would co-administration of a bacteriostatic drug interfere with the effects of penicillin?

1) Since most bacteriostatic drugs are produced from bacteria but penicillin is produced from mold, the two drugs are incompatible with each other.
2) A bacteriostatic drug interferes with the ability of a bacterial cell to take in compounds from the outside environment. Penicillin must be taken in by the cell in order to have its effect, so this would directly inhibit it.
3) The bacteriostatic drugs would bind directly to the penicillin, preventing both its uptake by the cell and its ability to perform its duty within the bacterial cell.
4) Penicillin interferes with cell wall production so it only works when the cells are actively replicating and MAKING new peptidoglycan. A bacteriostatic drug works by shutting down replication, holding the cells "static." This would interfere with the mode of action required by the penicillin.
5) Nothing interferes with the effects of penicillin. It is the most effective medication that we have, so is never used with the addition of a second drug when treating a person.

Answer 1

Co-administration of a bacteriostatic drug with penicillin can render penicillin less effective, as penicillin targets actively dividing bacterial cells, which are halted by bacteriostatic agents.

Step-by-step explanation:

The co-administration of a bacteriostatic drug can interfere with the effects of penicillin because penicillin requires actively dividing bacterial cells to exert its bactericidal effect. Penicillin works by inhibiting the synthesis of cell walls in replicating bacteria, which leads to cell lysis due to the defective cell wall. Bacteriostatic agents, on the other hand, inhibit bacterial growth and replication.

When the bacterial cells are not growing or dividing, the penicillin has nothing to disrupt, making it less effective. A bacteriostatic drug inhibits the ability of bacterial cells to take in compounds from the outside environment. As penicillin needs to be taken in by the bacterial cell to have its effect, the bacteriostatic drug would directly inhibit its uptake.