Michael R. Weitekamp

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Several new beta-lactam antibiotics impair normal hemostasis. Hypoprothrombinemia has occurred frequently with cephalosporins that possess a methylthiotetrazole substitution (cefamandole, moxalactam, and cefoperazone). The incidence ranges from 4% to 68%, and the risk is greatest in debilitated patients with cancer, intra-abdominal infection, or renal(More)
Coagulase-negative staphylococci are the most frequently isolated pathogens in prosthetic valve endocarditis and cause 5% of infections involving native valves. Distinguishing contamination from bacteremia may be challenging. The presence of heteroresistance in many strains makes rigorous susceptibility testing a requirement for selecting appropriate(More)
A bleeding diathesis characterized by in-vitro platelet dysfunction and prolongation of the template bleeding time (TBT) has been reported in patients receiving latamoxef ('moxalactam'), but not cefotaxime or cefoperazone. Hypoprothrombinaemia has been associated with the use of both latamoxef and cefoperazone in seriously ill and malnourished patients. We(More)
Veillonella parvula and alcalescens are anaerobic gram-negative cocci that, when isolated from anaerobic cultures of clinical specimens, are usually regarded as commensal organisms. Occasionally they play a pathogenic role and require antibiotic therapy. Limited clinical experience and in vitro susceptibility studies suggest that penicillin G is the drug of(More)
Gram-positive cocci are becoming increasingly resistant to traditionally used antimicrobial agents.Staphylococcus aureus, coagulase-negative staphylococci, the enterococcus, andStreptococcus pneumoniae are the most commonly encountered of such pathogens in clinical practice. Clinicians should be keenly aware of the usual types of infections that are caused(More)
Considering the current wide use of antimicrobial agents, the general internist is commonly faced with the patient at risk for diarrhea due to C. difficile. The diagnosis should be considered for any patient with diarrhea who has received any type of antibiotic therapy in the preceding 4-6 weeks. Symptoms may range from a minor bout of diarrhea to fulminant(More)
The combination of sensory neuropathy, ischemia and direct adverse effect on host defense mechanisms makes patients with diabetes vulnerable to foot infections. A high degree of clinical suspicion and vigilance is necessary for early diagnosis of soft tissue infections and their differentiation from noninfected ulcers. Diagnosis and assessment depend(More)
Beta-lactam antibiotics can directly impair hemostasis by two separate nonimmune mechanisms. First, the NMTT-substituted cephalosporin drugs may cause hypoprothrombinemia by interfering with the hepatic activation of clotting factors II, VII, IX, and X. Second, the antipseudomonal penicillins may cause the bleeding time to be prolonged by interfering with(More)