Risk of bleeding

Therapeutically t-PA and urokinase are the most important drugs for fibrinolytic therapy (myocardial infarction, stroke, massive pulmonary embolism). This treatment is associated with an enhanced risk of bleeding complications. 

When linezolid is used with antiplatelet drugs such as aspirin or die NSAIDs (see Chap. 18) diere is an increased risk of bleeding and thrombocytopenia When administered widi die MAOIs (see Chap. 31) the effects of the MAOIs are decreased. There is a risk of severe hypertension if linezolid is combined widi large amounts of food containingtyramine (eg, aged cheese, caffeinated beverages, yogurt, chocolate, red wine, beer, pepperoni). 

Food containing salicylate (curry powder, paprika, licorice, prunes, raisins, and tea) may increase the risk of adverse reactions. Coadministration of the salicylates with activated charcoal decreases the absorption of the salicylates. Antacids may decrease the effects of the salicylates. Coadministration with the carbonic anhydrase inhibitors increases the risk of salicylism. Aspirin may increase the risk of bleeding during... 

The term pasaon flower is used to denote many of the approximately 400 species of the herb. F saon flower has been used in medicine to treat pain, anxiety, and insomnia. Some herbalists use the herb to treat symptoms of parkinsonism. F saon flower is often used in combination with other herbs , such a valerian, chamomile, and hops, for promoting relaxation, rest and sleep. Although no adverse reactions have been reported, large doses may cause CNS depression. The use of passion flower is contraindicated in pregnancy and in patientstaking the monoamine oxidase inhibitors (MAOIs). Fission flower contains coumarin, and the risk of bleeding may be increased when used in patientstaking warfarin and pasaon flower. 

Administration of the thrombolytic drugp with aspirin, dipyridamole, or the anticoagulants may increase the risk of bleeding. 

When administered with cholestyramine or colestipol there is a decreased absorption of the oral thyroid preparations. These drugs should not be administered within 4 of 6 hours of the thyroid hormones. When administered with the oral anticoagulants there is an increased risk of bleeding. It may be advantageous to decrease the dosage of the anticoagulant when a thyroid preparation is prescribed. There is a decreased effectiveness of the digitalis preparation if taken with a thyroid preparation. 

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. 

Garlic Allium sativum Lowers blood sugar, cholesterol, and lipids May cause abnormal blood glucose levels Increased risk of bleeding in patients taking the coumarins, salicylates, or antiplatelet drugs. 

Aithal, G.P., Day, C.P., and Kesteven, P.J. et al. (1999). Association of polymorphisms in the cytochrome P450 C YP2C9 with warfarin dose requirement and risk of bleeding comph-cations. Lancet 353, 717-719. 

Do not use combination therapy in patients at high risk of bleeding or if the need for urgent CABG cannot be excluded... 

Administer vitamin Kj (1-2.5 mg enterally), especially if at increased risk of bleeding... 

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... 

Identify factors that place a patient at high risk of bleeding while receiving antithrombotic drugs. 

Factors that increase the risk of bleeding must be evaluated before thrombolytic therapy is initiated (i.e., recent surgery, trauma or internal bleeding, uncontrolled hypertension, recent stroke, or intracranial hemorrhage)... 

Avoid phlebotomy, arterial puncture, and other invasive procedures during thrombolytic therapy to minimize the risk of bleeding... 

Thrombocytopenia is another dose-limiting side effect of chemotherapy. The primary treatment for thrombocytopenia is platelet transfusions. The risk of bleeding is significant when platelet counts are less than 10,000/mm3 (10 x 109/L) ... 

Many dietary supplements have antiplatelet activity, which may increase the risk of bleeding when used concurrently with anticoagulants. Feverfew inhibits cyclooxygenase and phospholipase A2 and may interact with anticoagulants and potentiate the antiplatelet effect of aspirin. Other supplements that possess antiplatelet activity include but are not limited to garlic, ginkgo, vitamin E, vitamin A, and selenium. 

GP Ilb/IIIa inhibitors may increase the risk of bleeding, especially if given in the setting of recent (<4 hours) administration of fibrinolytic therapy. An immune-mediated thrombocytopenia occurs in about 5% of patients. 

During the early-to-moderate stages of vascular dementia, an aspirin a day can provide some protection from additional infarcts. However, daily aspirin does carry risks of bleeding and stomach irritation and should only be used under the supervision of a physician. 

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