Drug Metabolism & Transporters

Active Metabolite

TRAktif Metabolit
Also known as:Pharmacologically active metabolite

A product of drug metabolism that has pharmacological activity of its own, which may be similar to, greater than or different from that of the parent drug.

In depth

Active metabolites contribute to therapeutic and adverse effects and can prolong a drug's action when their half-life exceeds that of the parent, as with desmethyldiazepam (nordazepam) from diazepam and norfluoxetine from fluoxetine. Some have a different activity profile; norpethidine, for example, is neurotoxic and proconvulsant.

Many active metabolites are more polar than the parent and depend on renal excretion, so they accumulate in kidney impairment even when the parent drug is cleared by the liver. Morphine-6-glucuronide, which is analgesic and sedating, is a typical example.

Clinical pearl

In renal impairment, accumulation of active metabolites explains toxicity from morphine (morphine-6-glucuronide) and pethidine (norpethidine); drugs without renally cleared active metabolites are generally preferred.

Example drugs

Diazepam Fluoxetine Morphine pethidine Amitriptyline
TRIn Turkish

Aktif Metabolit

Kendi başına farmakolojik aktiviteye sahip olan ve bu aktivitesi ana ilacınkine benzer, ondan daha güçlü ya da ondan farklı olabilen bir ilaç metabolizması ürünüdür.

Aktif metabolitler terapötik ve advers etkilere katkıda bulunur ve yarılanma ömürleri ana ilacınkinden uzunsa etkiyi uzatabilir; diazepamdan oluşan desmetildiazepam (nordazepam) ve fluoksetinden oluşan norfluoksetin buna örnektir. Bazı metabolitlerin etki profili farklıdır; örneğin norpetidin nörotoksik ve konvülzan etkilidir.

Birçok aktif metabolit ana ilaçtan daha polardır ve böbrek yoluyla atılıma bağımlıdır; bu nedenle ana ilaç karaciğerden temizlense bile böbrek yetmezliğinde birikir. Analjezik ve sedatif etkili morfin-6-glukuronid tipik bir örnektir.

Böbrek yetmezliğinde morfin (morfin-6-glukuronid) ve petidin (norpetidin) toksisitesi aktif metabolitlerin birikmesiyle açıklanır; bu hastalarda böbrekten atılan aktif metaboliti olmayan ilaçlar genellikle tercih edilir.

Diğer adları:Farmakolojik olarak aktif metabolit
Updated 24.09.2026 1 views Educational reference — verify against current sources before clinical use.

Read next

ProdrugÖn İlaç (Prodrug)

A pharmacologically inactive or weakly active compound that is converted in the body, enzymatically or chemically, into the active drug.

 Drug Metabolismİlaç Metabolizması

The enzymatic biotransformation of drugs and other xenobiotics into metabolites that are usually more polar and more readily excreted, occurring mainly in the liver.

 Renal Dose AdjustmentBöbrek Fonksiyonuna Göre Doz Ayarlaması

The modification of the dose or dosing interval of a drug that is cleared, or has active or toxic metabolites cleared, by the kidneys, to prevent accumulation and toxicity in renal impairment.

 Elimination Half-LifeEliminasyon Yarı Ömrü

The time required for the plasma concentration of a drug to decrease by 50% during the elimination phase, reflecting how long the drug remains active in the body.

 Phase II MetabolismFaz II Metabolizma

Conjugation reactions in which an endogenous moiety such as glucuronic acid, sulfate, glutathione, an acetyl or a methyl group is attached to a drug or to its phase I metabolite.

 Phase I MetabolismFaz I Metabolizma

Functionalization reactions, mainly oxidation, reduction and hydrolysis, that introduce or unmask a polar group such as –OH, –NH2 or –COOH on a drug molecule.