What questions should be asked before placing a patient on anticoagulants?

Essential Questions Before Placing a Patient on Anticoagulants

Before initiating anticoagulation therapy, a thorough risk-benefit assessment must be conducted that evaluates the patient's thrombotic risk against their bleeding risk, with special attention to comorbidities, medication interactions, and patient-specific factors. 1

Medical History Assessment

• Evaluate previous stroke history, as this is a critical factor in determining both the need for anticoagulation and potential risks 1
• Assess history of gastrointestinal bleeding, which significantly increases bleeding risk during anticoagulation therapy 1
• Document any history of traumatic or repeated epidural/spinal punctures, which increases risk of spinal/epidural hematoma with anticoagulant use 2, 3
• Identify any history of spinal deformity or spinal surgery that may increase neuraxial bleeding risk 2, 3
• Determine if the patient has severe anemia, recent myocardial infarction, or renal failure, all of which can increase bleeding risk 1
• Evaluate for presence of liver disease, as this affects protein binding of anticoagulants and increases bleeding risk 1
• Screen for nutritional deficiencies that may lead to reduced protein and albumin levels, affecting drug pharmacokinetics 1
• Assess for neuromuscular diseases, Parkinson's disease, arthritis, or other conditions that may increase fall risk 1

Medication Review

• Identify all concomitant medications that could potentially interact with anticoagulants, especially those affecting CYP3A4 and P-glycoprotein pathways 1
• Document use of antiplatelet agents, as concomitant use significantly increases bleeding risk 1
• Screen for use of non-steroidal anti-inflammatory drugs (NSAIDs), which potentiate bleeding when combined with anticoagulants 1, 2
• Check for medications that are strong P-gp inhibitors (amiodarone, verapamil, ketoconazole, quinidine, clarithromycin) or inducers (rifampicin, St. John's wort) 1
• Identify use of CYP3A4 inhibitors (azole antimycotics, HIV protease inhibitors) or inducers (phenytoin, carbamazepine, phenobarbital) 1
• Document all dietary supplements, as these may interact with anticoagulants 1

Laboratory Assessment

• Obtain full blood count to establish baseline hemoglobin and platelet levels 1
• Check prothrombin time (PT) and activated partial thromboplastin time (aPTT) for baseline coagulation status 1
• Measure serum creatinine and calculate creatinine clearance (CrCl) using Cockroft-Gault or MDRD formula to guide dosing 1, 2
• Assess liver function with transaminases and bilirubin tests 1
• Screen for signs of coagulopathy that might contraindicate anticoagulation 1

Patient-Specific Factors

• Determine patient's age, as advanced age is an independent risk factor for bleeding in certain conditions 1
• Calculate body weight, which affects dosing of many anticoagulants 1
• Assess mobility status, as restricted mobility increases thrombotic risk but may also increase fall risk 1, 4
• Evaluate cognitive status and medication adherence capability 1
• Determine if the patient has adequate caregiver support if needed for medication management 1
• Assess the patient's living situation (institutional vs. home setting) 1
• Consider transportation access for follow-up visits and monitoring 1

Risk Assessment

• Calculate thrombotic risk using validated tools (e.g., CHA₂DS₂-VASc for atrial fibrillation) 1
• Assess bleeding risk using validated tools such as HAS-BLED 5
• Determine if the patient has a mechanical heart valve or valvular atrial fibrillation, which would necessitate specific anticoagulant choices 5
• Evaluate if the patient has active cancer, which may influence anticoagulant selection 5
• Determine if the VTE is provoked or unprovoked, as this affects duration of therapy 1
• Assess if the patient has chronic risk factors for VTE recurrence 1

Practical Considerations

• Discuss the patient's ability to afford medication and monitoring costs 1
• Evaluate the patient's willingness to adhere to the required monitoring schedule 1
• Assess the patient's quality of life and how anticoagulation might impact it 1
• Consider if the patient is a candidate for self-testing if on warfarin therapy 1
• Determine if the patient has an upcoming surgical or invasive procedure that might affect anticoagulation timing 1

Patient Education and Shared Decision-Making

• Discuss the risks and benefits of anticoagulation therapy with the patient and family 1
• Review signs and symptoms of bleeding that require medical attention 1
• Explain the importance of medication adherence and regular monitoring 1
• Discuss dietary considerations, particularly for vitamin K antagonists 1
• Document the discussion and factors leading to the clinical decision in the medical record 1

Common Pitfalls to Avoid

• Failing to reassess the need for antiplatelet therapy when combined with anticoagulation 1
• Not considering renal function when selecting and dosing anticoagulants 1, 2
• Overlooking drug-drug interactions that may increase bleeding risk 1
• Neglecting to create a follow-up plan with appropriate monitoring intervals 1
• Failing to provide the patient with an anticoagulation card or alert information 1
• Not discussing the risk of premature discontinuation of anticoagulation 2, 3

By systematically addressing these questions before initiating anticoagulation therapy, clinicians can optimize treatment efficacy while minimizing risks of adverse events.