Subterapeutisk

Subterapeutisk, or subtherapeutic, describes the administration of a drug at a dose below the level required to treat an active disease. In pharmacology, subtherapeutic concentrations are not sufficient to cure infection or relieve symptoms and can occur due to underdosing, poor adherence, or formulation issues. The term is used to describe exposure that falls outside the therapeutic window, with effects that may be minimal or unintended.

In veterinary medicine and agriculture, subtherapeutic dosing has historically been used to promote growth, improve feed efficiency, or prevent illness in large groups of animals. This often involves adding low levels of antibiotics to feed or water. The practice can influence gut microbiota and nutrient absorption, but its effects are variable and depend on species, dose, management, and environment.

Risks associated with subtherapeutic dosing are a central point of public health concern. The low-level use of antimicrobials can select for resistant bacteria and resistance genes, which may spread to humans through direct contact, the food chain, or the environment. These concerns have led many jurisdictions to regulate or ban subtherapeutic antibiotic use and to promote alternatives such as improved husbandry, vaccination, biosecurity, and the use of probiotics, prebiotics, or other non-antibiotic strategies.

Outside of antimicrobials, the term subtherapeutic can apply to any drug exposure that is deliberately or unintentionally lower than the therapeutic dose, underscoring the importance of proper dosing and adherence in achieving intended clinical outcomes.