With intermittent dosing there is less chance of causing resistant strains. Intermittent dosing also allows recovery of the host tissues from antioxidants, immunosuppressants, and protein synthesis inhibitor effects. It is more effective to chip away with intermittent antibiotics for long periods with eventual removal of the infectious agent than overwhelm the tissues with drug toxicity. Nucleophilic and lipophilic agents are localized, limiting systemic spread. Excessive long-term dosage could permanently damage organ functions and negate any benefits.
Gold salts are a good example.
Intermittent dosing allows the patient to tolerate the medication for years, if necessary. Antibiotic effectiveness is dependent on the tissue infected. Different IV or oral dosages may be required to clear the fatty synovium tissue than the genital tract, for example. Because of the complex pathogenicity, even with specific genetic coding, a pathogen becomes a set of conditions that regulates the host-parasite or saprophetic interaction. A pathogenic substance that causes a delayed or persistent abnormal host response in one set of conditions may be nonpathogenic in another set.