The Anxious Physicist

Personal blog of Dr Alex Mendelsohn

Category: Analysis

Bupropion UK supply update: GSK announces the return of Zyban in December 2023

September 15, 2023 /

This is an update to a previous post titled: Nearly a year on, Bupropion is still not available

I was worried the previous post might cause confusion to those who came across it hoping for the return of bupropion. Below, I’ve tried to go into a little detail about the potential reasons for the announced return – but please bear in mind I might have easily misinterpreted certain details, and an announcement from a secondary source does not mean resupply is confirmed. I’ve also given an update on the current availability of bupropion in the UK.

So, a notice popped up about a week ago in the form of an exclusive article by David Lipanovic of the Pharmaceutical Journal. It announced that bupropion will once again be supplied to the UK starting around December 2023.

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How I found Amdisen’s original research papers

July 3, 2023 /

Alex describes his experience of taking lithium and his search for information on its pharmacokinetic properties. He wanted to calculate his peak serum concentration and find out his approximate lithium half-life using the exponential decay formula. However, he found that there was no semi-log plot in the literature and no mention of the dual half-life of lithium. He searched for papers on simulations of the pharmacokinetic curve and found references to multi-compartmental models. Eventually, he found a chapter on lithium pharmacokinetics in a book and learned that the two half-lives he observed corresponded to the alpha and beta phases of lithium removal from blood vessels after peak concentration, which could be described using multicompartment models.

When I first started to take lithium, I wanted to calculate my peak serum concentration using my 12-hour sample value. I knew it was going to be a very rough estimation, but for me, doing the calculation made me feel less anxious about toxicity.

My plan was to use the exponential decay formula 1 to find the peak concentration (assuming the peak occurred around five hours). I wanted to find out, given I knew my serum creatinine levels, what my approximate lithium half-life was. I went looking for data in the lithium pharmacokinetic literature to figure this out.

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How imprecise language can lead to the loss of scientific knowledge: part 2

May 19, 2023 /

This blog post is in reference to my article in the May 2023 edition of the Lancet Psychiatry – Lithium Story: Eight Guidelines, Eight Recommendations. It is adapted from notes I sent to one of the editors when constructing the article

The blog post discusses the issue of imprecise language in scientific literature, specifically in the context of lithium pharmacokinetics. Alex provides two examples of unclear messaging from the literature and suggests solutions to improve clarity. Example 3 involves the lack of specificity about the timing of serum concentration values mentioned in a paper by Grandjean and Aubry, while Example 4 highlights a graph by R Hunter that is misleading due to the use of two scales on the x-axis and unclear labelling of subjects. Alex suggests that authors should provide clear and concise statements to remove ambiguity in their writing and improve the accuracy of their research.

In a previous blog post, I looked at two examples of imprecise language in a Grandjean and Aubry paper about lithium pharmacokinetics (which I used in my May 2023 Lancet Psychiatry article). In this post, to show that the problem is not limited to a single paragraph in a single review paper, I have included a couple more examples of unclear messaging.

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How imprecise language can lead to the loss of scientific knowledge: part 1

April 12, 2023 /

This blog post is in reference to my article in the May 2023 edition of the Lancet Psychiatry – Lithium Story: Eight Guidelines, Eight Recommendations. It is adapted from notes I sent to one of the editors when constructing the article.

The blog post is a criticism of the clarity and precision of the language used in lithium pharmacokinetic literature. The post focuses on a specific paragraph of the Grandjean paper that contains two examples of imprecise language. Alex explains the implications of the authoritative and inaccurate language used, which can lead to a false sense of understanding and clarity in a reader not familiar with the subject, and may cause a slow deterioration of the original research finding citation to citation, decade to decade. Alex also argues that imprecise language can cause the loss of scientific knowledge, using as an example the case of Amdisen and colleagues, who proposed taking patient serum concentrations at 12 hours in the 1970s, and soon after became standard practice worldwide, but with time the original research finding has been lost.

It might seem strange to say from someone writing a blog post criticising clarity and precision of language, but I personally find it very difficult to write clear and precise language. Goodness, if you could see my first-year PhD report!

But, because I had to work very hard to clarify the muddled thoughts in my head, I recognised mistakes in lithium pharmacokinetic literature similar to those I used to make in my writing.

In the Lancet Psychiatry article, I focus on the paper “Lithium: updated human knowledge using an evidence-based approach” by Etienne Marc Grandjean and Jean-Michael Aubry. It is an extensive collation of knowledge on lithium treatment. However, producing a paper with such breadth of knowledge, can in turn, lead to unclear and imprecise language given how much the authors are required to understand.

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