Oral anticoagulant (coumarin derivative)
Acenocoumarol is an oral anticoagulant used to prevent and treat blood clots (venous thrombosis, pulmonary embolism) and to prevent stroke in people with atrial fibrillation. It works by reducing the liver production of vitamin K-dependent clotting factors.
Also known as: Acenocumarol, Sintrom, Sinthrome
No documented drug–drug interactions for this medicine.
No documented food or drink interactions.
Prontuário 4.3.1.2: coumarins are contraindicated during the first trimester (teratogenic) and in the last weeks of pregnancy (risk of fetal or placental haemorrhage).
Contraindicated in pregnancy; use heparin when anticoagulation is needed.
Prontuário Terapêutico do INFARMED (11th ed., 2012) — 4.3.1.2
EMC-UK (Sinthrome 4.3) and Prontuário 4.3.1.2: contraindicated in conditions where the bleeding risk is greater than the clinical benefit — haemorrhagic diathesis or haemorrhagic blood dyscrasia, peptic ulcer or gastrointestinal, urogenital or respiratory tract haemorrhage, cerebrovascular haemorrhages, acute pericarditis and infective endocarditis.
Contraindicated in patients at high bleeding risk (active peptic ulcer, recent haemorrhage, haemorrhagic diathesis).
EMC-UK — Sinthrome SmPC 4.3: https://www.medicines.org.uk/emc/product/2058
The coumarins (acenocoumarol and warfarin) are contraindicated during the first trimester (teratogenic) and in the last weeks of pregnancy (risk of fetal or placental haemorrhage) (Prontuário 4.3.1.2).
Contraindicated in the 1st trimester (teratogenic) and in the last weeks (fetal/placental haemorrhage); alternative: heparin (does not cross the placenta).
No specific Prontuário data on breastfeeding; the coumarin class requires case-by-case evaluation.
Weigh the pregnancy risk before therapy in women of childbearing potential (contraception recommended).
Prontuário Terapêutico do INFARMED (11th ed., 2012) — Oral anticoagulants, 4.3.1.2 ; EMC-UK Sinthrome 4.6
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Indirect anticoagulant: reduces the hepatic synthesis of coagulation factors II, VII, IX and X by antagonising vitamin K; no in vitro anticoagulant effect. Effect apparent only after plasma depletion of the factors (2-3 days); monitored by INR (Prontuário 4.3.1.2).
Antagonism of vitamin K (phytonadione) — inhibition of gamma-carboxylation of vitamin K-dependent clotting factors.
Oral coumarin derivative; complete oral bioavailability. The effect depends on hepatic function (factor synthesis) and vitamin K availability (diet).
Interactions arise from altered metabolism (increase, e.g. carbamazepine; decrease, e.g. cimetidine), increased bleeding risk from antiplatelet action (e.g. acetylsalicylic acid) or potentiation of the anticoagulant action (NSAIDs, antihormones, antiarrhythmics and others) (Prontuário 4.3.1.2). EMC-UK records inhibition or induction of CYP2C9 as the main interaction mechanism.
Shorter half-life than warfarin (daily regimen); EMC-UK refers to frequent INR monitoring (twice weekly when starting or withdrawing a concomitant drug).
