Renal impairment in cystic fibrosis patients due to repeated intravenous aminoglycoside use.

Although there are reports of cases of acute renal failure occurring in cystic fibrosis (CF) patients, usually in association with the use of nephrotoxic antibiotic therapy, there have been no studies of renal function in this patient group. We hypothesized that long-term use of intravenous (IV) nephrotoxic antibiotics (aminoglycosides and colistin sulphomethate) may contribute to renal disease in CF patients. In a prospective study, we assessed creatinine clearance as an index of renal function with two techniques (24-hr urine collections and the Cockroft-Gault formula) in a group of 80 stable adult CF outpatients chronically infected with Pseudomonas aeruginosa but with no history of preceding renal disease. Using a multiple linear regression model, we evaluated their renal function in terms of their lifetime IV use of aminoglycosides and colistin. Between 31% (Cockroft-Gault formula method) and 42% (24-hr urine collection method) of patients had a creatinine clearance below normal range. Using either method, there was a strong correlation between aminoglycoside use and diminishing renal function (r=- 0.32, P=0.0055), which was potentiated by the coadministration of colistin (r=- 0.42, P <0.0002). However, there was no correlation with colistin when used in combination with other antibiotics alone (r=0.18, P=NS). Repeated IV aminoglycoside use in CF is associated with long-term renal damage. Although this effect is potentiated by colistin, colistin on its own in moderate doses does not appear to be nephrotoxic. IV aminoglycosides should be used cautiously in CF patients, with regular monitoring of renal function.

Bronchoscopic insertion of Gianturco stents for the palliation of malignant lung disease: 10 year experience.

Malignant large airway obstruction is life threatening and may not be amenable to urgent radiotherapy. Palliative airway stenting is difficult and traditionally carried out under general anaesthesia and fluoroscopy. We have shown that self expanding Gianturco metal stents can be placed under local anaesthesia using fibreoptic bronchoscopy and direct vision for the treatment of malignant airway tumours, and report our 10 year experience. All referrals for stenting referred to our unit between 1990 and 1999 were included, looking for histological type, number and site of stents, complications of the procedure, other interventions, and survival. One hundred and sixty two patients (average age 64 years, (range 21-89)) had 307 stents inserted during 167 procedures (144 primary lung tumours, 18 secondary malignancy). There were no operative deaths, but three patients developed a pneumothorax, one requiring intercostal drain insertion. Average survival following stent insertion was less for primary lung cancer than for secondary disease (103 vs. 431 days, P<0.001). There were no excess complications in a subgroup of 64 patients treated locally by oncologists, even when stenting was the primary procedure. This technique is useful in palliating life threatening airway obstruction, particularly for secondary cancer, and can be used in any centre undertaking fibreoptic bronchoscopy.

A world-wide internet survey of public knowledge about tuberculosis.

Four simple multiple-choice questions about tuberculosis (TB) were posted on a non-medical internet site for a 2-month period. A total of 564 responses were received. Sixty-two were excluded as individuals had made multiple attempts at the questions. Sixty-five per cent of responses were from North America, 14.5% from Europe and 12% from Australia and New Zealand, with only a small number of responses from Africa, the Indian subcontinent and South America. Of the respondents 49.5% correctly answered that cough is the commonest symptom of TB, 45% knew that TB was transmitted mainly by air-borne droplets, 37.8% knew that TB was caused by a bacterium. Only 19.5% knew that the most important risk factor for developing TB was HIV infection and only 4% answered all questions correctly. This survey suggests that knowledge about tuberculosis is limited in computer-literate individuals throughout the world.

Mycobacterial culture results of smear-positive patients with suspected pulmonary tuberculosis in Liverpool.

The aim of this study was to assess the final mycobacterial culture results of patients with smear-positive sputum or bronchial washings and to investigate the efficiency of local tuberculosis (TB) contact-tracing. Retrospective analysis of mycobacterial cultures and contact-tracing was performed in every patient with smear-positive sputum or bronchoalveolar lavage (BAL) in two Liverpool teaching hospitals (1996-1998). Of these patients 116 with smear-positive sputum or BAL were identified. Mycobacterium tuberculosis (M. tuberculosis) was cultured in 57 (49%), environmental mycobacteria in 37 (32%) and cultures were negative in 22 (19%) of the patients. Contact-tracing information was available in 107 of the 116 (92%) patients. A total number of 1,357 contacts were screened for possible tuberculosis. Of these, 420 (31%) were contacts of patients who cultured environmental organisms or had negative cultures. In this study, 51% of smear-positive patients in Liverpool did not have tuberculosis. Inefficiencies in current contact-tracing procedures have been identified which result from screening contacts of index cases that are subsequently found not to have cultured Mycobacterium tuberculosis. The authors believe that there are clear grounds for using rapid tests to identify and type mycobacteria more quickly than current solid or liquid media methods. It is also suggested that regional variations in the frequency of infection with environmental mycobacteria should be considered when formulating tuberculosis contact-tracing procedures.

Topiramate in clinical practice: first year's postlicensing experience in a specialist epilepsy clinic.

OBJECTIVE: Topiramate became available for use in October 1995. Meta-analysis of its randomised controlled data suggested that it may be the most potent of the new antiepileptic drugs. The aim of this study was to assess the first year's postlicensing experience in a specialist regional epilepsy clinic. METHODS: The case notes of 174 of 178 patients who were prescribed topiramate in the 12 months between November 1995 and October 1996 were retrospectively reviewed. Data were collected on seizure type, classification of epilepsy, presence or absence of learning difficulties, depression, or behavioural problems, co-medication, dosage escalation, efficacy, adverse events, whether or not the patient was still on topiramate and, if not, the reason for withdrawal. Kaplan-Meier survival analysis was used to estimate the overall retention rate and log rank tests were used to determine factors associated with stopping topiramate. RESULTS: Overall 90 of 174 patients had ceased taking topiramate at the end of the study. The median "survival time" was 427 days (95% CI 362.9-491.1). The cumulative probability for remaining on topiramate at 1 year was 0.549 (95% CI 0.475-0.623). The retention rate in patients in whom topiramate was substituted for another drug was significantly higher than in those in whom it was added to current therapy. Adverse events (CNS related) were the most common reason for stopping topiramate. Eight patients with partial and one patient with juvenile myoclonic epilepsy became seizure free. CONCLUSIONS: There is a significant (20-25%) chance of being intolerant to topiramate at relatively low doses. Substituting topiramate for another antiepileptic drug may reduce the chances of drug withdrawal. If topiramate is tolerated there is a good chance of worthwhile improvement in seizure control. These data, although not derived from randomised controlled trials, represent pragmatic use of novel antiepileptic drugs in "real life" and may be helpful to non-specialists when prescribing topiramate.