This article does not endorse the drug (or any other drug for that matter). See disclaimer policy.
Low sodium in blood (Hyponatremia) is an extremely common condition especially in patients with heart failure and liver diseases.
Hyponatremia is defined as a serum sodium less than 135 mmol/l.
Up until now the treatment of this condition involved free water restriction and removal of inciting factors. Now a new drug – Tolvaptan promises to change it all.
Tolvaptan acts by blocking the V2 receptor (vasopressin) which is responsible for reabsorption of electrolyte free water in the kidneys.
The New England Journal of Medicine, Nov 16, 2006 issue has an article outlining the efficacy of this drug. The investigators found that Tolvaptan was superior to placebo in correcting low serum sodium. The total duration of the study was for 1 month. After that period the drug was discontinued and patients were assessed for relapse of hyponatremia. Relapse did occur, however the frequency of its occurrence was similar to that of placebo.
Most common side effects of tolvaptan included – increased frequency of urination, thirst, dry mouth and constipation.
The main problem with the drug is that once approved, most clinicians will prescribe it for for a very long time especially in patients prone to developing and remaining hyponatremic. Since the study duration was only for 30 days, many new side effects may appear when the drug is finally marketed.
Two similar drugs are already approved – Mozavaptan in Japan and Conivaptan in US (Conivaptan is parentally administered for Syndrome of Inappropriate Anti-Diuretic Hormone Secretion).
References: New England Journal of Medicine
More on Hyponatremia – Wikipedia, eMedicine,
Technorati Tags: ADH, Conivaptan, Mozavaptan, Hyponatremia, Tolvaptan, Vasopressin
This article has been recently quoted in an article titled “Content of weblogs written by health professionals” published in the Journal of General Internal Medicine by implying that it is a product endorsement. The actual quote is:
“Up until now the treatment of this condition involved free water restriction and removal of inciting factors. Now a new drug – Tolvaptan promises to change it all.”
However, the article missed out the remaining post which in the end had my take on Tolvaptan – “The main problem with the drug is that once approved, most clinicians will prescribe it for for a very long time especially in patients prone to developing and remaining hyponatremic. Since the study duration was only for 30 days, many new side effects may appear when the drug is finally marketed.”
Also the article was written in context of describing an article published in New England Journal of medicine and not for drug promotion which the article failed to mention. I should also add that I have no relationship with any pharmaceutical company as the article later implies by writing:
“A recent survey reveals that 29% of blog authors have been approached by public relations professionals to endorse specific products, and 52% of them have written one post endorsing such products in their blog content.23 These endorsements are not advertise- ments that appear on the website; they are written into the blog narrative, often without any acknowledgement that they are paid promotions. Although we did find blogs that promoted health care products within their entries, we were unable to determine whether these were paid endorsements, because we found no disclosures indicating authors’ conflicts of interest.”
I pursue blogging because I have a passion for computers and technology and believe that we can help ourselves (physicians) as well as our patients to try to empower them with the latest knowledge in medicine that they can discuss with their physicians.
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[...] article Tolvaptan – New drug for low sodium in blood” has been recently quoted in an article titled “Content of weblogs written by health [...]
Can someone tell me the source of the survey that looked at the influence of PR folks on health blogs? Thanks.
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The link to the article is Content of weblogs written by health professionals (pdf link)
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