Cidal drug: removal of all bacteriodes due to drug (primarily used for immunocompromised) -as penicillin
Other antibiotics are considered bactericidal; their action kills the organisms without any help from the immune system.
For most infections, outcomes using appropriate bacteriostatic versus bactericidal drugs are similar; however, for certain infections, bactericidal drugs are preferred. Such infections include endocarditis, meningitis, and infections in neutropenic patients. The immune system may not be as effective in fighting these infections because of the anatomic location or the immunosuppression of the patient.
Disadvantage of bactericidal: rapid bacterial lysis e.g. in meningitis with overwhelming inflammatory response with increased mortality. i.e Bactericidal may lead to release of toxins and microbial contents leading to subsequent illness and inflammatory responses.
So Bactericidal drugs are preferred in:
- Impaired host defense
- Infections with poor blood flow (endocarditis, endovascular infections , osteomyelitis ………
- Low WBC (<500)
- Cancer patients
- CSF penetration (meningitis)