section name header

Pronunciation

WAR-fa-rin

Classifications

Therapeutic Classification: anticoagulants

Pharmacologic Classification: coumarins

Indications

BEERS REMS

Action

Therapeutic Effects:

Pharmacokinetics

Absorption: Well absorbed from the GI tract after oral administration.

Distribution: Minimally distributed to tissues.

Protein Binding: 99%.

Metabolism/Excretion: Primarily metabolized by the liver via the CYP2C9 isoenzyme, with some metabolism via the CYP3A4 isoenzyme; the CYP2C9 isoenzyme exhibits genetic polymorphism (intermediate or poor metabolizers may have significantly (S)-warfarin concentrations and an risk of adverse reactions).

Half-life: 42 hr.

Time/Action Profile

(effects on coagulation tests)

ROUTEONSETPEAKDURATION
PO36–72 hr5–7 days2–5 days

†At a constant dosedharaAfter discontinuation

Contraind./Precautions

Contraindicated in:

Use Cautiously in:

Adv. Reactions/Side Effects

Derm: dermal necrosis.

GI: cramps, nausea.

GU: CALCIPHYLAXIS.

Hemat: BLEEDING.
Misc: fever.

Interactions

Drug-Drug:

Drug-Natural Products:

Drug-Food:

Route/Dosage

see Calculator

Availability

(Generic available)

Assessment

Lab Test Considerations: Toxicity and Overdose:

Implementation

Patient/Family Teaching

Evaluation/Desired Outcomes

US Brand Names

Coumadin, Jantoven

Pill Image

warfarinsodium_195_9002.jpg