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S B Thorsteinsson

Publications and source records attributed to S B Thorsteinsson.

35 records · Page 2Linked to original sources
PubMed1982

Dose-dependent pharmacokinetics of azlocillin compared to mezlocillin.

The pharmacokinetics of azlocillin at intravenous doses of 1.0, 2.0 and 5.0 g and of 2.0 g mezlocillin were studied in a cross-over study on 10 healthy volunteers. The serum concentrations and total area under the serum curves for azlocillin increased more than expected from the multiples of the dose size. Likewise, the percentage of urinary excretion of an antibacterially active agent increased steadily with higher doses. The same applied to the serum half-life (t 1/2), whereas the total body clearance was reduced. All these characteristics are indicative of dose-dependent, i.e. capacity-limited pharmacokinetics. The t 1/2 was 0.89, 0.98, and 1.53 h for each dose. For 2.0 g mezlocillin, the serum values, urinary recovery, and t 1/2 were lower than the values after the same dose of azlocillin. The t 1/2 was 0.64 h. The total body clearance was 12,0, 9.2, and 6.4 liters/h for the three doses of azlocillin and 14.4 liters/h for 2. g mezlocillin. Dose dependence appears to be more pronounced with azlocillin than found previously with mezlocillin. Unchanged azlocillin and its biotransformation products are excreted more slowly than mezlocillin and its metabolites.

Adult↗
PubMed1982

Lymphogranuloma venereum: review of clinical manifestations, epidemiology, diagnosis, and treatment.

Lymphogranuloma venereum (LGV) continues to be a rare disease in the Scandinavian countries; cases are, with rare exceptions, contracted elsewhere. The clinical manifestations of LGV include extragenital infections such as pharyngitis, with cervical lymphadenopathy, and proctitis. Delayed diagnosis can lead to late complications, with disabling anatomic defects as an end result. Diagnosis usually is based on clinical grounds, with serological confirmation. Other chlamydial infections besides LGV can cause seroconversion, particularly in tests for complement-fixation antibodies. Treatment with tetracyclines is effective to eradicate the causative agent, provided that the treatment course is of adequate length. Only rarely is surgical intervention needed, and then primarily to correct anatomic abnormalities in far-advanced cases.

Anti-Bacterial Agents↗
PubMed1981

Pharmacokinetics of mezlocillin during haemodialysis.

The pharmacokinetics of mezlocillin was studied in six patients with end stage renal failure. They were given 2.0 g mezlocillin intravenously both during and without haemodialysis. The mean serum half-life was 2.1 h off dialysis and 1.2 h on dialysis. The distribution volumes were of the same order with and without dialysis. While the patients are on haemodialysis, dosage may be as in patients with normal renal function. Only very minor or no dosage adjustments in relation to normal dosage appear necessary for mezlocillin when the patients are not on dialysis.

Adult↗
PubMed1976

Quantitative urinalysis. Diagnosing urinary tract infection in men.

Using a hemocytometer, we determined the number of white blood cells (WBCs) per milliliter in uncentrifuged urine specimens. Uninfected urine usually contained less than or equal to 10(3) WBCs per milliliter, although up to 8 X 10(3) WBCs per milliliter were observed. Infected urine regularly contained greater than 10(4) WBCs per milliliter, and the mean WBC count per millimeter for urine from infected patients was 3.1 X 10(5). The absence of pyuria thus provides strong evidence against the presence of urinary tract infection. Similar results were obtained in patients who had indwelling catheters, suggesting that bacteriuria reflects the presence of infection rather than colonization. Valid data are easily obtainable by quantitative urinalysis of uncentrifuged urine specimens. There are obvious differences in WBCs per milliliter, with little overlap between infected and uninfected urine. This method of analysis should replace traditional means of counting WBCs per visual field in a centrifuged, resuspended urine sediment.

Adult↗
PubMed1976

Inhibition of the antibacterial activity of gentamicin by urine.

Urinary levels of antibiotics determine the outcome of treatment of most urinary tract infections. The antibacterial effect of gentamicin against Escherichia coli and Pseudomonas aeruginosa in urine was studied. With use of urinary constituents in concentrations normally found in human urine, it was shown that urine has an inhibitory effect that is dependent upon the acidity and total osmolality of the urine, as well as upon the presence of individual solutes. Up to 40 times as much gentamicin may be needed to prevent the growth of E. coli or P. aeruginosa in concentrated, acidic human urine as is required in broth. This inhibitory effect may be particularly important when urinary concentrations of gentamicin are reduced either because of a reduction in dosage or because of decreased excretion due to renal insufficiency.

Calcium Chloride↗
PubMed1976

Vertebral osteomyelitis. Still a diagnostic pitfall.

Vertebral osteomyelitis is still a diagnostic problem. Nonspecific symptoms (low-grade fever, malaise, and weight loss) may dominate. Specific infections may be suggested by the history, and the diagnosis may be reinforced by a transient response to antibiotics. The patient may have symptoms resulting from a secondary paravertebral abscess. Even with fever, back pain, and point tenderness over the vertebral column, the correct diagnosis may not be considered. Predisposing conditions include drug addiction, instrumentation of the infected urinary tract, bacteremia from other causes, or previous back surgery. Diagnosis is made by roentgenographic studies and isolation of the causative organism from blood cultures or from the infected area. Staphylococcus aureus is the most common pathogen, although other microorganisms may be responsible. Intensive intravenous antibiotic treatment appears to be curative, without surgical debridement, external stabilization, or porlonged oral administration of antibiotics.

Adult↗
PubMed1975

The diagnostic value of sputum culture in acute pneumonia.

In a prospective study of patients with acute pneumonia, the results of bacteriologic analysis of sputum, transtracheal aspirate (TA), and bronchial aspirate (BA) were compared. Streptococcus pneumoniae was grown from all three sources as the predominant organism in 13 of 16 cases; the remaining three patients had nonbacterial lung disease. These data support the traditional concept that culture of the sputum is highly reliable in providing a correct diagnosis in acute pneumonia.

Acute Disease↗
PubMed1975

Effectiveness of achievable urinary concentrations of tetracyclines against "tetracycline-resistant" pathogenic bacteria.

Hospitalized patients with urinary tract infections caused by Pseudomonas aeruginosa or other bacterial pathogens are frequently treated with parenteral antibiotics such as gentamicin. Many of these organisms are shown by Kirby-Bauer disk sensitivity testing to be resistant to tetracycline. One hundred seventy-one such tetracycline-resistant bacterial isolates were studied; 84% were found to be sensitive to achievable urinary concentrations of tetracycline. Two patients with long-standing chronic urinary tract infection with Pseudomonas were treated with tetracycline for a year and a half with excellent results. In a pilot clinical trial, eight of 12 hospitalized patients with urinary tract infection were treated successfully with tetracycline without regard to disk sensitivity data. Institution of tetracycline as soon as the microscopic diagnosis of urinary tract infection is made might be an acceptable empiric approach to the treatment of urinary infection in hospitalized patients who do not show evidence of sepsis.

Bacteriuria↗
PubMed1975

Leptospirosis: an underdiagnosed cause of acute febrile illness.

Two cases of leptospirosis diagnosed at the Texas Medical Center in a two-week period are presented. Most cases of leptospirosis go undiagnosed because the symptoms and signs are nonspecific. Leptospirosis should enter the differential diagnosis when symptoms of influenzal illness, aseptic meningitis, and viral gastroenteritis occur, especially if abnormal hepatic and renal function are shown to be present. Many, but by no means all, patients will give history of exposure to livestock or rodents. Diagnosis is best made by serologic methods; Treatment is usually not required since the disease is self-limited, and even in the more severe form, antibiotics have not been conclusively shown to be of benefit.

Acute Disease↗
PubMedDate not supplied

Transintestinal elimination of ciprofloxacin.

This study identified the routes of elimination of ciprofloxacin in two groups of five subjects each: one of healthy volunteers; the other of patients with severe renal failure having mean creatinine clearance of 12 ml/min (range, 8-16 ml/min). Each subject received one dose of 200 mg ciprofloxacin infused intravenously (IV) over 30 min. In an effort to recover the total drug administered, all urine and feces were collected for 7 days following dosing. Blood samples were drawn at set intervals. Serum, urine, and feces were assayed for ciprofloxacin and metabolites by high-pressure liquid chromatography. The ciprofloxacin elimination half-life was 3.9 +/- 0.4 hr in the healthy volunteers and 11.2 +/- 2.5 hr in the patients with severe renal failure. The total 7-day recovery of ciprofloxacin and its metabolites in urine and feces ranged from 74.0% to 114.7% of the dose (mean, 96.3 +/- 14.1%) in normal subjects and from 48.5% to 109.1% (mean, 88.1 +/- 20.9%) in patients. The dose of ciprofloxacin recovered in urine was 65.3 +/- 10.7% in healthy subjects and 19.0 +/- 15.9% in impaired patients (reduction factor, 3.4). In contrast, the dose recovered in feces was 11.4 +/- 2.6% in the group of normal subjects and 37.2 +/- 12.5% in the group of patients with impaired renal function in a 3.3-fold increase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Pharmacokinetic profile of fosfomycin trometamol.

The pharmacokinetics of fosfomycin trometamol has been assessed in 12 healthy volunteers given oral doses of 2, 3, and 4 g of fosfomycin and 3 g intravenously of fosfomycin as fosfomycin sodium, all in the fasting state. The assay was microbiological (Proteus mirabilis ATCC 21100). There was a gradual rise in both peak serum concentrations and total area under the curve by rising oral doses, from 16.0 mg/l and 106.7 mg x h/l, after 2 g to 30.9 mg/l and 189.7 mg x h/l after 4 g respectively. The serum half-life was 4 h after the oral doses and 2.1 h after the intravenous dose. After the oral doses, the amounts excreted in urine in the active form ranged from 36 to 40% compared to 93% after the intravenous dose. The bioavailability was slightly below 40%. Concentrations in urine covers the usual urinary tract pathogens after oral doses of 2, 3, and 4 g.

Administration, Oral↗