Prescribing antibiotics.

A specific antibiotic is prescribed not for its effect on the patient but for its effect on the microorganism. Antibiotics have a unique toxicity because of antibiotic-resistant bacteria in the patient. Lack of response to the antibiotic may be due to selection of the wrong drug, inadequate dosage, inappropriate route of administration, failure of the drug to be distributed to the infected site, or metabolism and excretion so that no active drug is present.