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PubMed Central Canada to be taken offline in February 2018

On February 23, 2018, PubMed Central Canada (PMC Canada) will be taken offline permanently. No author manuscripts will be deleted, and the approximately 2,900 manuscripts authored by Canadian Institutes of Health Research (CIHR)-funded researchers currently in the archive will be copied to the National Research Council’s (NRC) Digital Repository over the coming months. These manuscripts along with all other content will also remain publicly searchable on PubMed Central (US) and Europe PubMed Central, meaning such manuscripts will continue to be compliant with the Tri-Agency Open Access Policy on Publications.

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1.  Effects of alpha-interferon on theophylline pharmacokinetics and metabolism. 
1. The influence of alpha-interferon (Roferon-A) on the pharmacokinetics and metabolism of theophylline was studied in healthy adults. Roferon-A was administered as an intra-muscular injection (3 x 10(6) iu) once-a-day over 3 days. One week prior to and immediately after this course a single 20 min aminophylline infusion (4 mg kg-1) was given. 2. Blood samples for theophylline analysis were taken over 48 h. Urine was collected up to 72 h and assayed for theophylline and its major metabolites 3-methylxanthine, 1,3-dimethyluric acid and 1-methyluric acid. 3. Pharmacokinetic parameters for theophylline in plasma were calculated. From urinary excretion data the overall metabolic clearance of theophylline and clearances for formation of the metabolites were calculated. 4. After interferon administration, there was a significant increase of approximately 15% in the mean values of the terminal elimination half-life, area under the curve and mean residence time of theophylline in association with a similar decrease in plasma clearance (P less than 0.05). Formation clearances of the metabolites tended to be smaller after treatment, but only the change in the overall clearance of theophylline was significantly different (P less than 0.05). There was no systematic shift in the metabolic pattern of theophylline. 5. Additional investigations of the influence of the duration of alpha-interferon treatment are necessary before definite conclusions can be drawn about the mechanism and the clinical relevance of the described interaction.
PMCID: PMC1379807  PMID: 2757895
2.  Pharmacokinetic and clinical considerations in the choice of a hypnotic 
British Journal of Clinical Pharmacology  1983;16(Suppl 1):5S-10S.
1 Not only has insomnia become much more frequent in the last hundred years but its causes have also changed considerably.
2 In the treatment of insomnia, benzodiazepines—because of their additional anxiolytic effect—offer substantial advantages over other sleep-inducing agents.
3 The residual fraction—the quotient of plasma concentration at 12 h after drug intake to maximum plasma concentration—makes it possible to differentiate between the benzodiazepines according to their suitability as anxiolytics or hypnotics.
4 Midazolam has the lowest residual fraction of all known benzodiazepines and thus, administered in the appropriate dosage, also has the shortest duration of activity.
PMCID: PMC1428092  PMID: 6138081

Results 1-2 (2)