Off-target activity

Drug biological activity

Off-target activity is biological activity of a drug that is different from and not at that of its intended biological target. It most commonly contributes to side effects. However, in some cases, off-target activity can be taken advantage of for therapeutic purposes. An example of this is the repurposing of the antimineralocorticoid and diuretic spironolactone, which was found to produce feminization and gynecomastia as side effects, for use as an antiandrogen in the treatment of androgen-dependent conditions like acne and hirsutism in women.^[1]

References

^ Mohammadi E, Benfeitas R, Turkez H, Boren J, Nielsen J, Uhlen M, Mardinoglu A (September 2020). "Applications of Genome-Wide Screening and Systems Biology Approaches in Drug Repositioning". Cancers (Basel). 12 (9): 2694. doi:10.3390/cancers12092694. PMC 7563533. PMID 32967266.

Pharmacology

Ligand (biochemistry)

Excitatory	Agonist Endogenous agonist Irreversible agonist Partial agonist Superagonist Physiological agonist

Inhibitory	Antagonist Competitive antagonist Irreversible antagonist Physiological antagonist Inverse agonist Enzyme inhibitor

Pharmacodynamics

Activity at receptor	Mechanism of action Mode of action Binding Receptor (biochemistry) Desensitization (medicine)

Other effects of ligand	Selectivity (Binding, Functional) Pleiotropy (drugs) Non-specific effect of vaccines Adverse effect Toxicity (Neurotoxicity)

Analysis	Dose–response relationship Hill equation (biochemistry) Schild plot Del Castillo Katz model Cheng-Prussoff Equation Methods (Organ bath, Ligand binding assay, Patch clamp)

Metrics	Efficacy Intrinsic activity Potency (EC50, IC50, ED50, LD50, TD50) Therapeutic index Affinity

Pharmacokinetics

Metrics	Loading dose Volume of distribution (Initial) Rate of infusion Onset of action Biological half-life Plasma protein binding Bioavailability

LADME	(L)ADME: (Liberation) Absorption Distribution Metabolism Excretion (Clearance)

Compartment
Bioequivalence

Related
fields

Neuroscience and psychology	Neuropsychopharmacology Neuropharmacology Psychopharmacology Electrophysiology

Medicine	Clinical pharmacology Pharmacy Medicinal chemistry Pharmacoepidemiology

Biochemistry and genetics	Pharmacoinformatics Pharmacogenetics Pharmacogenomics

Toxicology	Pharmacotoxicology Neurotoxicology

Drug discovery	Classical pharmacology Reverse pharmacology

Other

Coinduction (anesthetics)

Combination therapy

Functional analog (chemistry)

Polypharmacology

Chemotherapy

Lists of drugs

WHO list of essential medicines

Tolerance and resistance	Drug tolerance Tachyphylaxis Drug resistance Antibiotic resistance Multiple drug resistance

Antimicrobial pharmacology	Antimicrobial pharmacodynamics Minimum inhibitory concentration Bacteriostatic Minimum bactericidal concentration Bactericide