singledrug

Singledrug is a term used in medicine to describe a therapeutic approach in which a single pharmacologic agent is used to treat a condition, as opposed to regimens that rely on multiple drugs. It is often referred to as monotherapy, emphasizing the use of one active drug as the primary treatment, sometimes alongside non-pharmacologic measures or supportive care.

Applications of singledrug vary by field. In infectious diseases, singledrug regimens are common for uncomplicated infections when guidelines identify a single agent with adequate activity against the pathogen. In chronic conditions such as hypertension, diabetes, or hyperlipidemia, monotherapy with a single agent is frequently used as a first-line option, with additional agents added if treatment targets are not reached. In psychiatry and oncology, monotherapy is used in some scenarios (for example, mild to moderate depressive disorders or certain cancers) but many cases ultimately require combination or sequential therapies to address complexity, resistance, or symptom burden.

Advantages of singledrug therapy include reduced risk of drug-drug interactions, simpler dosing, lower cost, and potentially improved patient adherence. Limitations arise when a disease is multifactorial, when rapid or robust control is needed, or when resistance or heterogeneity reduces efficacy. In infections, resistance can develop if a single agent is insufficient to fully eradicate the pathogen. In cancer and other chronic diseases, monotherapy may be inadequate for achieving durable control.

Decision-making for singledrug versus combination therapy depends on disease severity, pathogen susceptibility, patient comorbidities, guideline recommendations, and expected response. Monitoring focuses on efficacy, safety, tolerability, and adherence.

See also: monotherapy, polypharmacy, combination therapy, antimicrobial stewardship.