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Biomedical subjects

H Lode

Publications and source records attributed to H Lode.

352 records · Page 20Linked to original sources
PubMedDate not supplied

Pharmacokinetic effects of altered plasma protein binding of drugs in renal disease.

The measurement of plasma drug concentrations provides no insight into the relationship between the free and the plasma-protein-bound fractions of drugs. Plasma protein binding may decrease in renal disease due to uremia, hypoalbuminemia, or due to drug interactions. Decreased plasma protein binding leads to an increase in free plasma fraction causing an increase in volume of distribution and a shorter elimination half life. The increase in the apparent volume of distribution and the shorter elimination half life cause a decrease in total plasma concentration. Therefore, the free drug concentration is more reliable than the total plasma concentration for therapeutic drug monitoring. However, the free amount in plasma and in tissue and the tissue-bound amount remain unchanged under steady state conditions. Thus, a decrease in plasma protein binding in renal disease usually does not lead to increased drug toxicity, and alteration of drug dosage is not required, although the total plasma concentration may be found to be considerably lower than normal. In addition to plasma protein binding, alteration of tissue binding must also be considered for the determination of the appropriate dosage of some drugs in renal disease.

Biological Availability↗
PubMedDate not supplied

Pneumocystis carinii pneumonia as a complication of immunosuppressive therapy.

BACKGROUND: Patients receiving immunosuppressive therapy with corticosteroids and cytotoxic agents may develop opportunistic infections such as Pneumocystis carinii pneumonia (PCP). This indicates a severe T-cell defect, but so far there are no established criteria for identifying patients at risk. PATIENTS AND METHODS: CD4+ and CD8+ T-lymphocyte counts were determined by flow cytometry in seven HIV-negative patients who developed PCP as a complication of immunosuppressive treatment. RESULTS: CD4+ T-lymphocyte counts (T-helper phenotype) were less than 200/microl in all seven patients (mean 90.6/microl). The markedly reduced CD4 counts measured in these patients are similar to those observed in organ transplant recipients who developed PCP during immunosuppressive therapy for prevention of graft rejection and in HIV-positive patients with PCP as an AIDS-defining illness. CONCLUSION: Measuring CD4+ T-lymphocyte counts may be helpful in determining the risk of PCP not only in HIV-positive patients, but also in patients receiving immunosuppressive therapy. The risk of acquiring PCP seems to increase when CD4+ lymphocyte counts drop below 200/microl, regardless of the underlying disease.

CD4 Lymphocyte Count↗
PubMedDate not supplied

Drug interactions with quinolones.

The mechanisms involved in drug interactions may be either pharmacokinetic or pharmacodynamic. Pharmacokinetic interactions are the leading events and are caused by alterations in absorption, distribution, metabolism, and elimination of one drug by another. The reported interactions of new quinolones are due to a decrease in antimicrobial activity at low pH, a Mg++-dependent reduction in efficacy, and a probenecid-induced decrease in tubular secretion of ciprofloxacin. The reduction of theophylline clearance by those quinolones that are metabolized primarily in the liver (enoxacin and ciprofloxacin) is of clinical relevance; also, the interactions of quinolones with Mg++-containing antacids, which result in tremendous loss of bioavailability, are of therapeutic importance.

Absorption↗
PubMedDate not supplied

Pharmacokinetics and clinical results of parenterally administered new quinolones in humans.

Some of the newer quinolone derivatives (e.g., ciprofloxacin, enoxacin, fleroxacin, ofloxacin, pefloxacin, and amifloxacin) can be administered intravenously. Parenteral quinolone therapy is indicated primarily for patients receiving intensive care or in the early postoperative phase, for perioperative prophylaxis, and for patients with disturbed absorption. With respect to pharmacokinetic parameters, there are no substantial differences between parenteral and oral preparations of the quinolones. The quinolones have a long elimination half-life, a high volume of distribution, low protein-binding capacity, renal as well as extrarenal elimination, and limited biotransformation. Thus far, the limited data concerning the clinical efficacy and safety of quinolones are available only for the parenteral forms of ciprofloxacin, pefloxacin, and ofloxacin. The data available indicate good to excellent clinical and antimicrobiologic responses in patients with complicated urinary tract infections; respiratory tract infections; intraabdominal, bone and joint, skin and soft tissue infections; and difficult-to-treat infections (e.g., septicemia, nosocomial pneumonia, and fever of unknown origin in neutropenic patients).

Anti-Infective Agents↗
PubMedDate not supplied

Respiratory tract infections: when is antibiotic therapy indicated?

Antibiotic therapy of purulent bronchitis is a matter of continuing controversy. However, recent studies on the pathogenicity of airway hyperreactivity, granulocyte-mediated bronchial obstruction, and histamine production of Haemophilus influenzae indicate an important role for viral and bacterial infections in exacerbations of chronic obstructive lung disease (COLD). Considering the different stages of COLD in relation to lung function, bacterial pathogens, and relevant findings and symptoms of the individual patient, antibiotic treatment should be based on three different degrees of severity.

Acute Disease↗