Introduction to coronary artery stents and their pharmacotherapeutic management.

OBJECTIVE: To provide an introduction to coronary artery stents and their pharmacologic management, including anticoagulant therapy and newer antiplatelet regimens. DATA SOURCES: A MEDLINE and current journal search of relevant articles that evaluated coronary stent success rates and anticoagulation or antiplatelet regimens. STUDY SELECTION: Data from the use of primarily the Palmaz-Schatz stent were included. Studies using vitamin K antagonists that are not commercially available in the US were excluded unless they compared an antiplatelet regimen with anticoagulation using the international normalized ratio (INR). DATA SYNTHESIS: Limitations with percutaneous transluminal coronary angioplasty (PTCA), such as ischemic complications and restenosis, have led to the advent of intracoronary stenting. However, the placement of a stent within the coronary artery lumen is associated with a risk of thrombotic events. Despite current postprocedural anticoagulation and antiplatelet regimens, thrombosis occurs at rates ranging from 0.6% to 21%. When anticoagulation is deemed appropriate, it should be used for 1-2 months and the INR should be maintained between 2 and 3.5. Anticoagulation appears to have no effect on the development of restenosis, but has been shown to cause significant hemorrhagic events in 5-13.5% of patients. Newer data continue to define the subsets of patients who may be managed with antiplatelet agents alone. Combinations of aspirin and ticlopidine or aspirin alone may be used to manage patients who fulfill the following criteria: optimal stent placement, high-pressure inflation, and adequate coronary size. CONCLUSIONS: Coronary artery stenting is a novel approach for the management of coronary artery disease, but is associated with the complication of stent thrombosis. Anticoagulation reduces the risk of stent thrombosis, but is associated with bleeding risk. Selected patients may be successfully managed with antiplatelet agents only. More data are needed to better define the optimal antithrombotic regimen.

Medical liability risk avoidance: a case for adopting the International Normalized Ratio (INR) system.

Since bleeding is a common adverse effect associated with the oral anticoagulant warfarin, maximizing the therapeutic potential of this drug requires close laboratory monitoring. The International Normalized Ratio (INR) is a system that has been developed to improve and standardize the assessment of the intensity of oral anticoagulation therapy. Clinical information and medicolegal arguments supporting the adoption of this system are reviewed. The potential for improvement in patient outcomes and minimization of medical liability favors the adoption of the INR system.

Oral vitamin K1: an option to reduce warfarin's activity.

OBJECTIVE: To report 6 patients taking oral vitamin K1 (phytonadione) to reduce warfarin's activity. CASE SUMMARY: Six patient cases are summarized in which oral vitamin K1 was used to reduce the international normalized ratio (INR) in patients at risk of bleeding. DISCUSSION: The use of oral vitamin K1 to antagonize warfarin's effects is discussed, as well as the benefits of oral vitamin K1 administration and the disadvantages of parenteral vitamin K1 administration. In addition, an extensive literature review of the discovery and clinical development of warfarin and vitamin K1 is described. CONCLUSIONS: In patients receiving warfarin therapy who have an increased INR and are at risk of bleeding, oral vitamin K1 therapy may be safer, less painful, and more cost-effective than the traditional parenteral route of administration.

Situational obstacles to dietary adherence for adults with diabetes.

OBJECTIVE: To develop a taxonomy of everyday situations that create obstacles for adherence to dietary management in patients with diabetes. SUBJECTS: Twenty-six adults with diabetes (12 with insulin-dependent diabetes mellitus and 14 with non-insulin-dependent diabetes mellitus) were recruited from an outpatient diabetes clinic. MAIN OUTCOME MEASURES: Subjects were interviewed to identify problem situations that create obstacles for dietary adherence. The resulting 69 situations were judged for the presence or absence of 32 environmental features using a reliable coding system. STATISTICAL ANALYSIS: A hierarchical cluster analysis was used to identify homogeneous groups of dietary adherence obstacles. RESULTS: Twelve types of problem situations were identified: negative emotions, resisting temptation, eating out, feeling deprived, time pressure, tempted to relapse, planning, competing priorities, social events, family support, food refusal, and friends' support. CONCLUSIONS: The resulting taxonomy provides an outline for the detailed assessment of obstacles to dietary adherence. An individual's ability to cope with this array of obstacles to dietary adherence should be assessed so treatment can be individualized.

Situational obstacles to adherence for adolescents with diabetes.

Twenty adolescents with insulin-dependent diabetes mellitus were interviewed to obtain samples of problem situations that create obstacles to dietary adherence. The resulting 57 situations were analyzed using a reliable coding system to determine the presence or absence of 28 stimulus features. A hierarchical cluster analysis was used to identify 10 relatively homogeneous categories of obstacles to dietary adherence: being tempted to stop trying; negative emotional eating; facing forbidden foods; peer interpersonal conflict; competing priorities; eating at school; social events and holidays; food cravings; snacking when home, alone, or bored; and social pressure to eat. Diabetes educators should consider an individual's ability to cope with this array of obstacles to adherence when individualizing treatment. Dietary intervention then can be personalized to address specific situational obstacles.

Analgesics and warfarin. A case that brings up questions and cautions.

This case report describes prolongation of a patient's prothrombin time and partial thromboplastin time possibly due to coadministration of warfarin and an overdose of an acetaminophen-propoxyphene combination analgesic. Patients receive warfarin for many indications, and concomitant use of an analgesic agent is commonly required. These patients should be closely observed if a combination acetaminophen-propoxyphene product is prescribed. Finally, patients receiving warfarin should be warned about the risks of use (and overdose) of unprescribed medications.

Cefotetan-induced disulfiram-type reactions and hypoprothrombinemia.

A double-blind, placebo-controlled study in eight healthy male volunteers was conducted to study possible disulfiram-type reactions and hypoprothrombinemia associated with cefotetan administration. Three doses of cefotetan (2 g) or of placebo were administered at 12-h intervals. Ethanol (0.5 g/kg of total body weight) was ingested 1 h after the third dose. Blood ethanol, serum acetaldehyde, and prothrombin times were measured throughout the study. Heart rate, blood pressure, and clinical signs as well as symptoms suggestive of a disulfiram-type reaction were also noted. Five of eight volunteers that received cefotetan showed significant flushing. A significant increase in heart rate also was noted. No change in mean arterial pressure was observed during the cefotetan phase, and no one experienced nausea or vomiting. No statistical differences were observed between phases with respect to ethanol area under the time-concentration curve, elimination rate, or serum acetaldehyde concentrations. A slight but statistically significant increase in prothrombin time also was observed with cefotetan. This study suggests that patients receiving cefotetan might be at risk to develop disulfiram-type reactions and hypoprothrombinemia.

Alternative antirejection treatment with steroids or antilymphoblast globulin in renal transplant patients receiving cyclosporine.

An alternative antirejection protocol using corticosteroids or ALG for reversal of initial acute rejections was studied during a 2-year period in 112 mismatched renal transplant recipients receiving CsA. The majority of patients were cadaver transplant recipients. Thirty-five initial episodes of acute rejection occurred; twelve patients with early or histologically severe rejection were treated with ALG and 23 patients with late, nonsevere rejection received corticosteroid therapy. The overall success rate was approximately 90%, with 21 of 23 corticosteroid-treated patients and ten of 12 ALG-treated patients responding to therapy. The two treatment modalities did not differ with respect to subsequent hospital admissions for fever, second rejections, graft survival, or patient survival. Corticosteroid-treated patients realized significant cost savings and required a shorter hospital stay when compared to ALG-treated patients. An alternative antirejection treatment protocol may be highly effective, safe, and cost beneficial.