Candesartan Cilextil is prescribed specifically for heart failure and hypertension. I’d been taking a generic version of this drug for about a year when, suddenly, a fortnight ago, my local pharmacy switched brands. And I found myself having to double the dose to get even close to the effect of the previous brand.
The original tablets were from Takeda UK Ltd. The defective ones from Mylan, in Potters Bar. Not only were the tablets half the size of the Takeda ones, they were quite clearly half the strength too, if not less, despite the strength marked on the box being the same.
This is unacceptable and could have put my life at risk had a been the sort of patient who ignored such things – there are more of them than you might think. But I’m not, I know exactly the response I should get from all my drugs and, in this instance, I didn’t get it.
Now the problem with the generic drug market is that anyone can apply for a licence – and get it. Such licences are subject to inspection, but because of the sheer number of companies jumping on the generic drug supply bandwagon in this country, inspection is retrospective, if it happens at all.
The Medicines and Healthcare products Regulatory Agency (MHRA), is the regulatory body, and I should report this matter to them (so, indeed, should my GP, who should have asked me for the distributor’s name and the lot number, but he couldn’t give a toss either, ditto the pharmacy), but I know from past experience that they simply couldn’t give a shit. Their attitude, for public consumption, at least, is that all generic drugs are perfect, when any user of these things in bulk, like me, with 15 of the buggers to take every day, knows that quality can, and does, vary wildly. And often dangerously.
A classic example of how bad these drugs can be is generic Salbutamol inhalers (Ventolin), which are, frankly, useless (so much so that in hospital spirometry units they use branded Ventolin as the gold standard or, at least, did last time I was there). Luckily, my local pharmacy dispenses Ventolin too. Generic Salbutamol nebules are not a problem due to the very much greater dose, but in my experience are less effective than the branded version.
Another example is generic Naproxen (a NSAID). One tablet of bought-in, US-made, Naproxen, gives me the same result as two tablets of the UK generic drug.
My advice, given that the trade in generic drugs is effectively unregulated – a fact that was the subject of a journalistic investigation not too long ago, in the Guardian I think – is to treat any change in your response to a drug as a defect in the drug, not you, and get it changed without delay. If you enjoy an exercise in frustration, and being told you don’t know what you’re talking about, then feel free to also report it to the MHRA. Good luck with that!
But back to Candesartan, and the first thing that rang alarm bells was the tiny size of the Mylan tablets, less than half the size of the Takeda tabs. OK, so the difference could have been that they used less of the normal bulking agents, often used to make tablets a manageable size when the amount of drug is tiny (4mg in this case). Or, as it turned out, they could actually contain half, or less than half, of the amount of drug that they should.
I did actually consider, briefly, whether it was possible I had dramatically deteriorated in the 24 hours between the last of the Takeda drug and the first of the Mylan, but dismissed the idea as nonsense. I am deteriorating, but to do so, so dramatically, in such a short space of time is, I believe, impossible.
I might be wrong, of course, and in serious trouble, but as my cardiologist, Dr. Nick Newall, at Arrowe Park Hospital has absented himself and the hospital clearly has no interest in setting me up with another cardiologist, I stand by my conclusion that the drug is seriously under the declared strength.
So if you’re taking Candesartan from Mylan, and you feel a lot worse, don’t just assume you are worse, tell your GP – s/he might be more inclined to report the matter than mine – and should prescribe something better.
Feel free to take a copy of this post with you, should you need to.
PS I suppose it’s possible that the Takeda tablets contained double the amount of the drug, in much the same way as there really might be Lunarians on the moon!