Drug reference

Acenocoumarol

Vitamin · Anticoagulant

Also known as Nicoumalone

VitaminAnticoagulant

CDSCO approved

EXCRETION

—

not curated

INTERACTIONS

—

none in our sources

PREGNANCY

Should not be given in the first trimester of pregnancy. Acenocoumarol crosses the placenta with risk of congenital malformations, and placental, fetal, or neonatal haemorrhage, especially during the last few weeks of pregnancy and at delivery. Avoid in pregnancy, especially in the first and third trimesters, if possible. Stopping before the sixth week of gestation may largely avoid the risk of fetal abnormality.

FDA category + note

Mechanism

Acenocoumarol is an oral anticoagulant that antagonizes the effects of vitamin K. It prevents the synthesis of active forms of vitamin K-dependent coagulation factors II, VII, IX, and X, and proteins C and S, which are synthesized in the liver. The full anticoagulant effect typically develops over at least 48 to 72 hours.

Indications

Prevention of thrombus formation or extension of an existing thrombus in the slower-moving venous circulationPrevention of thromboembolic diseaseAnticoagulation

Dosing

Adult: Loading: 8–12 mg; Maintenance: 2–8 mg
Hepatic adjustment: Manufacturers advise caution in mild to moderate hepatic impairment; avoid in severe impairment.
Geriatric: Prescription potentially inappropriate for elderly patients with: concurrent significant bleeding risk (such as uncontrolled severe hypertension, bleeding diathesis, or recent non-trivial spontaneous bleeding), dual therapy with an antiplatelet agent in patients with stable coronary, cerebrovascular, or peripheral arterial disease without a clear indication for anticoagulant therapy, or for first…

Pharmacokinetics

Onset

At least 48 to 72 hours for full anticoagulant effect to develop

Half-life

8 hours (active metabolite overall t½ is about 24 hours)

Metabolism

Metabolized, with R- and S-enantiomers differing in metabolism; commercial preparations are racemic mixtures.

Contraindications

First trimester of pregnancy
Severe hepatic impairment
Cerebral artery thrombosis as first-line therapy
Peripheral artery occlusion as first-line therapy
Hyperthyroidism
Peptic ulcer
Postpartum (delay until risk of haemorrhage is low, usually 5–7 days after delivery)
Recent ischaemic stroke
Recent surgery
Uncontrolled hypertension
Concurrent significant bleeding risk (e.g., uncontrolled severe hypertension, bleeding diathesis, recent non-trivial spontaneous bleeding) in the elderly
Dual therapy with an antiplatelet agent in patients with stable coronary, cerebrovascular, or peripheral arterial disease without a clear indication for anticoagulant therapy in the elderly
For first deep venous thrombosis without continuing provoking risk factors for longer than 6 months in the elderly
For first pulmonary embolus without continuing provoking risk factors for longer than 12 months in the elderly

Side effects

Common

HaemorrhageOral ulcerationG.i.t. disturbancesDermatitisUrticariaAlopecia

Serious

Alopecia
Nausea
Vomiting
Blue toe syndrome
CNS haemorrhage
Diarrhoea
Fever
Haemothorax
Jaundice
Pancreatitis
Skin necrosis (increased risk in patients with protein C or protein S deficiency)
Skin reactions