Page 88 - MNU-PM502- Pharmaeutical Microbiology Theoritical Book

Pharm D- Clinical Pharmacy Program Third Level Pharmaceutical Microbiology& Antimicrobials (PM 502)

Bacteriostatic drugs: inhibit or delay bacterial growth and replication
(Tetracyclines, Sulfonamides, Macrolides)

• Bacteriostatic antibiotics rely on the immune system to eradicate the non-
multiplying bacteria from the patient.

What about immunocompromised patients

• Some antibiotics can be both bacteriostatic and bactericidal, depending on the
dose, duration of exposure and the state of the invading bacteria.

• For example, aminoglycosides, fluoroquinolones, and metronidazole exert
concentration-dependent killing characteristics; their rate of killing increases as

the drug concentration increases.

• The immune system appears to be relatively ineffective in the eradication of
bacteria in certain types of infections, such as meningitis and endocarditis.

• In these infections, bactericidal antibiotics should be used instead of
bacteriostatic antibiotics.

• The susceptibility of a bacterial isolate to a given antibiotic is quantified by the
minimum inhibitory concentration (MIC) and the minimum bactericidal
concentration (MBC).

3- Mode of action

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