Warfarin Aspirin

Because of reported antiplatelet effects, patients using anticlotting medications (eg, warfarin, aspirin, ibuprofen) should use garlic cautiously. Additional monitoring of blood pressure and signs and symptoms of bleeding is warranted. Garlic may reduce the bioavailability of saquinavir, an antiviral protease inhibitor, but it does not appear to affect the bioavailability of ritonavir. 

Agent COUMADIN Warfarin ASPIRIN PLAVIX AZD6I40 Prasugrel AGGRASTAT Tiroflban INTEGRILIN Rptifibatide REOPRO Abciximab... 

A randomised blinded trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). Lancet 348 1329-1339 Chimowitz MI, Kokkinos J, Strong J et al. (1995). The Warfarin-Aspirin Symptomatic Intracranial Disease Study. Neurology 45 1488-1493... 

Cost-effectiveness analysis is concerned with how to attain a given objective at minimum financial cost, e.g. prevention of postsurgical venous thromboembolism by heparins, warfarin, aspirin, external pneumatic compression. Analysis includes cost of materials, adverse effects, any tests, nursing and doctor time, duration of stay in hospital (which may greatly exceed the cost of the drug). 

Warfarin + aspirin Significant increase in anticoagulant effect with possible severe Gl blood loss Displacement from protein Combination should be avoided if possible. Use alternative analgesic such as paracetamol or pentazocine... 

Hurlen M, Abdelnoor M, Smith P, et al. Warfarin, aspirin, or both after myocardial infarction. N Engl J Med 2002 347 969-974. 

Use of warfarin in the secondary prevention of noncardioem-bolic stroke was addressed in the Warfarin Aspirin Recurrent Stroke Study. In 2206 patients with recent stroke, warfarin (INR = 1.4—2.8) was not superior to aspirin 325 mg/day in the prevention of recurrent events. This led many clinicians to abandon the practice of using warfarin as an alternative agent in patients who suffered recurrent events while on antiplatelet therapy in favor of combination or alternate antiplatelet therapy. 

Lj-Saw-Hee FL, Blann AD, Lip GY Effects of fixed low-dose warfarin, aspirin-warfarin combination... 

A frequency of ALT elevation >3x ULN of 0-2% was observed among patients treated with the comparators (placebo, warfarin, LMWH/warfarin, aspirin) (Lee et al. 2005). Among 233 patients treated with ximelagatran and 35 patients treated with placebo, the pattern of the hepatic enzyme elevations was evaluated. Of these, 76% (150) and 43% (15) were judged to have hepatocellular injury, while 24% (48) and 57% (20) were judged to have mixed or cholestatic injury (Lewis et al. 2008). 

Many physicians prescribe anticoagulants and antiplatelet medications to prevent thromboembolic events and access thrombosis in dialysis patients despite limited evidence of their efficacy in this population. Chan et al. [54] concluded that warfarin, aspirin, or clopidogrel prescription is associated with higher mortality among hemodialysis patients [54]. 

Administration of zafirlukast and aspirin increases plasma levels of zafirlukast, When zafirlukast is administered with warfarin, there is an increased effect of the anti coagulant. Administration of zafirlukast and theophylline or erythromycin may result in a decreased level of zafirlukast. Administration of montelukast with other drugs has not revealed any adverse responses. Administration of montelukast with aspirin and NSAIDs is avoided in patients with known aspirin sensitivity. Administration of zileuton with propranolol increases the activity or the propranolol with theophylline increases serum theophylline levels and with warfarin may increase prothrombin time (PT). A prothrombin blood test should be done regularly in the event dosages of warfarin need to be decreased. 

Plasma digoxin levels may decrease when the drug is administered with bleomycin. When bleomycin is used witii cisplatin, there is an increased risk of bleomycin toxicity Pulmonary toxicity may occur when bleomycin is administered with other antineoplastic drugs. Plicamycin, mitomycin, mitoxantrone, and dactino-mycin have an additive bone marrow depressant effect when administered with other antineoplastic drugs. In addition, mitomycin, mitoxantrone, and dactinomycin decrease antibody response to live virus vaccines. Dactinomycin potentiates or reactivates skin or gastrointestinal reactions of radiation therapy There is an increased risk of bleeding when plicamycin is administered witii aspirin, warfarin, heparin, and the NSAIDs. 

Five randomized primary and secondary prevention trials " have demonstrated the efficacy and safety of warfarin in preventing AF-related stroke. Pooled data from these trials demonstrated a 68% reduction in ischemic stroke (95% Cl 50-79) and an intracerebral hemorrhage rate of <1% per year. The data for aspirin suggested that it had a lesser effect, with a 36% risk reduction (95% Cl 4—57). 

Administered to achieve an INR of 2.5 (range 2-3) in combination with low-dose aspirin pharmacotherapy (<100 mg daily [Chest guidelines] or 75-162 mg daily [Circulation guidelines]) for 3 mo postmyocardial infarction. Repeat echocardiogram before discontinuing warfarin pharmacotherapy... 

Do not combine with an antiplatelet agent o If patient experiences a systemic embolism while receiving warfarin and has a therapeutic INR, add aspirin 75-100 mg/d. For patients unable to take aspirin, then add dipyridamole 400 mg/d or clopidogel 75 mg/d. Immediate release dipyridamole needs an acidic gastric pH (<4) for adequate absorption... 

Either UFH or LMWH should be administered to patients with NSTE ACS. Therapy should be continued for up to 48 hours or until the end of the angiography or PCI procedure. In patients initiating warfarin therapy, UFH or LMWHs should be continued until the International Normalized Ratio (INR) with warfarin is in the therapeutic range for 2 consecutive days. The addition of UFH to aspirin reduces the rate of death or MI in patients with NSTE ACS.47 Enoxaparin was mentioned as preferred over UFH in the 2002 ACC/AHA clinical practice guidelines, as two large clinical trials found a reduction in the combined endpoint of death, MI, or need for PCI in patients... 

Stroke Prevention All patients with paroxysmal, persistent, or permanent AF should receive therapy for stroke prevention, unless compelling contraindications exist. A decision strategy for stroke prevention in AF is presented in Fig. 6-9.27 In general, most patients require therapy with warfarin in some patients with no additional risk factors for stroke, aspirin may be acceptable. For some patients, serious consideration of the benefits of warfarin versus the risks of bleeding associated with warfarin therapy is warranted. The potential bleeding risks associated with warfarin may outweigh the benefits in... 

Warfarin has not been adequately studied in non-cardioembolic stroke, but it is often recommended in patients after antiplatelet agents fail. One small retrospective study suggests that warfarin is better than aspirin.30 More recent clinical trials have not found oral anticoagulation in those patients without atrial fibrillation or carotid stenosis to be better than antiplatelet therapy. In the majority of patients without atrial fibrillation, antiplatelet therapy is recommended over warfarin. In patients with atrial fibrillation, long-term anticoagulation with warfarin is recommended and is effective in both primary and secondary prevention of stroke.12 The goal International Normalized Ratio (INR) for this indication is 2 to 3. 

Application of topical salicylates can lead to systemic effects, especially if the product is applied liberally. Repeated application and occlusion with a wrap or bandage also can increase systemic concentrations.41 Salicylate-containing counterirritants should be used with caution in patients in whom systemic salicylates are contraindicated, such as patients with severe asthma or aspirin allergy.42 Topical salicylates have been reported to increase prothrombin time in patients on warfarin and should be used with caution in patients on oral anticoagulants.43... 

Evaluate patient comorbidities and medications to determine if additional work-up is necessary prior to tumor debulking surgery. Do any medications need to be stopped or changed prior to surgery (e.g., aspirin, warfarin, or non-steroidal anti-inflammatory agents) ... 

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