Marcuphen (Phenprocoumon)

Marcuphen, a vitamin K antagonist, is used in several thrombo‑preventive pathways.

• Venous thromboembolism: prevents clot formation and recurrence in patients at risk.
• Atrial fibrillation: reduces the incidence of stroke and systemic embolism in non‑valvular atrial fibrillation.
• Orthopedic surgery: provides prophylaxis against postoperative deep‑vein thrombosis and pulmonary embolism after joint replacement or fracture repair.

• Phenprocoumon inhibits vitamin K epoxide reductase, an enzyme required to recycle vitamin K to its active form. By blocking this step, the synthesis of vitamin K‑dependent clotting factors II, VII, IX and X in the liver is reduced, leading to prolonged coagulation times and decreased thrombus formation.

Phenprocoumon may cause a range of adverse reactions, from mild to life‑threatening.

Common Side Effects

• Bleeding or bruising: easy bruising, nosebleeds, gum bleeding.
• Gastrointestinal discomfort: nausea, abdominal pain, dyspepsia.
• Headache or dizziness.
• Skin rash or mild itching.

Serious or Rare Side Effects

• Severe hemorrhage: intracranial, gastrointestinal or retroperitoneal bleeding.
• Skin necrosis or severe cutaneous reactions.
• Allergic anaphylaxis.
• Hepatic enzyme elevation.
• Thrombocytopenia or other hematologic abnormalities.

Patients receiving Marcuphen require careful monitoring and risk assessment.

• Monitor INR: regular blood tests to keep coagulation within therapeutic range.
• Assess bleeding risk: evaluate history of ulcers, surgery or trauma before initiation.
• Adjust dose in liver impairment: reduced metabolic clearance may increase anticoagulant effect.
• Caution in renal dysfunction: monitor for accumulation and bleeding.
• Avoid in uncontrolled hypertension: high blood pressure raises hemorrhage risk.
• Store at ambient temperature: keep below 25 °C, in original packaging, protected from moisture and light.

Phenprocoumon interacts with many medicines that affect coagulation or its metabolism.

Major Interactions (Avoid)

• Concurrent anticoagulants (e.g., heparin, warfarin): additive bleeding risk.
• Strong CYP2C9 inhibitors (e.g., amiodarone, fluconazole, metronidazole): may cause excessive anticoagulation.
• Antiplatelet agents (e.g., aspirin, clopidogrel): heightened hemorrhage potential.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs): increase gastrointestinal bleeding.
• Certain antibiotics (e.g., trimethoprim‑sulfamethoxazole): potentiate anticoagulant effect.

Moderate Interactions (Monitor Closely)

• Moderate CYP2C9 inhibitors (e.g., macrolide antibiotics, SSRIs): may require dose adjustment.
• Herbal supplements (e.g., ginkgo, garlic, ginger): can affect platelet function.
• Vitamin K‑rich foods: may reduce anticoagulant efficacy.
• Diuretics and ACE inhibitors: monitor blood pressure and renal function.