Five Minutes with Professor James McCarthy | The Safety of Tafenoquine
Welcome back to Five Minutes, the podcast series where we speak to the most interesting people in the world of malaria.
Following our interview with Dr Remington Nevin on the FDA’s approval of Tafenoquine, we’re excited to launch a series of podcast interviews surround the drug.
We’ll be bringing you perspective from across the board, from doctors, researchers, veterans and others. We want to ensure that everyone’s voice is heard and that our coverage does not endorse a particular side or viewpoint.
You’ll be able to access all of these interviews online by heading to fightmalaria.uk/Tafenoquine2018
With that being said, I’m delighted to be speaking with Professor James McCarthy who works at the QIMR Berghofer Medical Research Institute. He leads the Clinical Tropical Medicine laboratory (CTM) and develops and applies clinical trial systems. Such systems involve the deliberate infection of human volunteers with malaria to evaluate potential antimalarial vaccines and drugs.
This is Five Minutes with Professor James McCarthy
So to start off with, is Tafenoquine a safe drug?
Well, all the available evidence from clinical trials indicates that Tafenoquine is a very safe drug, it’s been tested in more than 4000 people. And aside from a few uncommon side effects that have been seen with this drug, which is commonly seen with many other drugs in clinical trials, it is shown to be quite safe.
Do you believe the individuals who are showing symptoms after taking Tafenoquine are suffering from neuropsychiatric side effects?
Well, it’s a complicated matter. Certainly, the other drug mefloquine which they some of them did take has been associated with this problem. But it’s always very difficult in these situations to distinguish the occurrence of post-traumatic stress disorder (PTSD) or some other psychological problem. Or also people who have a mental health condition that becomes unmasked while they working in a military environment and is that due to the antimalarial drugs or is it or would that have occurred anyhow and that’s the fundamental question that can we say that people who have got these side effects are those side effects caused by the Mefloquine or Tafenoquine or would they have occurred anyhow and that really fundamental problem that we are unable to, in my mind, make a definitive association of the problems they’re complaining of with the administration of this drug.
You mentioned Mefloquine there and Mefloquine and Tafenoquine are similar, right?
No, they’re not similar at all and that part of the problem. They’ve probably got a misleading name, they’ve got ‘quine’ at the end of them. But if you look at the chemical structure of the two drugs, they’re very different. It’s like comparing dogs and cats or apples and oranges because they’ve got the same ‘quine’ name at the end that everybody thinks they look the same behave the same their chemical properties and they start fixing experimental animals and all of their properties in the human body are entirely different.
But they’re both Quinolines?
Well, quinolines is a class of drugs determined by the chemical structure, it’s like saying oranges and apples are both fruits.
I’d like to play you a clip from our interview with Dr Remington Nevin of The Quinism Foundation. This is what he says to say about Quinolines.
This is a class of drug with inherent CNS toxicity users very likely contributing significantly to the global burden of mental illness and neuropsychiatric disability.
Is he right?
I don’t believe he is right for two reasons. First of all, as I said before these are two different classes of drugs albeit with a very similar name. And the second reason is that there’s been a lot of toxicity tests done. When you give a rat high doses of mefloquine may all show these all the neurologic side effect and when you examine the brains of the rats their distinctive features, when you test Tafenoquine in the same model there are no side effects of the same order. So I believe it’s very misleading to class two drugs together.
Dr James McCarthy, thank you so much.