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Guilt by Association
By Kevin Frost
A patient a few years ago came in for an operation, for which she had to stay a few days post-operatively. During that time she developed a UTI, and so was treated with trimethoprim. 36 hours into the course of trimethoprim, she developed severe hallucinations, despite no history of psychiatric illness.
Her husband then did something that we, as healthcare providers, hate; yet it's something that I and I'm sure a fair few of you, as patients, do frequently whenever presented with a diagnosis. Her husband googled it.
Now I love google for searching the internet. It's not only incredibly good and the product of a company that brings free and innovative web applications, in addition to a track record of (at least 99% of the time) doing no evil. But, as has been said many times, if "a little knowledge is a bad thing" - how bad is a lot of knowledge, easily accessed? For it to be used properly, information has to be properly interpreted. We currently live in an information age, but unfortunately that doesn't mean we live in a wisdom age.
Back to the patient - the husband brought in this article and showed it first to the nurses and then to her surgeon, who stopped the antibiotic immediately.
I came along later, saw that it referred not to trimethoprim, but to co-trimoxazole (a 5/1 mix of trimethoprim and a sulphonamide). We don't use Co-trimoxazole for UTI's beacuse the CSM thinks that it's tendency to stop blood cells forming is too much of a risk. Our American cousins disagree, and use co-trimoxazole widely for UTIs.
The BNF entry for co-trimoxazole does list hallucinations as a potential side-effect, while the entry for trimethoprim does not. I did a search for references to confirm that trimethoprim is not associatied with this ADR, and couldn't find anything other than yellow card reports -which gives an assumptive association between drug and side effect, not a conclusive cause-and-effect relationship - that indicated that trimethoprim can cause this problem.
Getting hold of a consultant surgeon can prove difficult, and the nature of the pecking order in hospitals makes the rest of their team very reluctant to go against their decisions unless there's a very good reason why; so I could not verbally share my input. The psychiatrists did get involved and the patient left the hospital on antipsychotic medication and with a warning to never never never ever take trimethoprim again.
I dutifuly filled in a yellow card for the reaction, but I remain skeptical about the role of the trimethoprim in this patient's case. In my opinion, it was innocent and this was a case of guilt by association.
Her husband then did something that we, as healthcare providers, hate; yet it's something that I and I'm sure a fair few of you, as patients, do frequently whenever presented with a diagnosis. Her husband googled it.
Now I love google for searching the internet. It's not only incredibly good and the product of a company that brings free and innovative web applications, in addition to a track record of (at least 99% of the time) doing no evil. But, as has been said many times, if "a little knowledge is a bad thing" - how bad is a lot of knowledge, easily accessed? For it to be used properly, information has to be properly interpreted. We currently live in an information age, but unfortunately that doesn't mean we live in a wisdom age.
Back to the patient - the husband brought in this article and showed it first to the nurses and then to her surgeon, who stopped the antibiotic immediately.
I came along later, saw that it referred not to trimethoprim, but to co-trimoxazole (a 5/1 mix of trimethoprim and a sulphonamide). We don't use Co-trimoxazole for UTI's beacuse the CSM thinks that it's tendency to stop blood cells forming is too much of a risk. Our American cousins disagree, and use co-trimoxazole widely for UTIs.
The BNF entry for co-trimoxazole does list hallucinations as a potential side-effect, while the entry for trimethoprim does not. I did a search for references to confirm that trimethoprim is not associatied with this ADR, and couldn't find anything other than yellow card reports -which gives an assumptive association between drug and side effect, not a conclusive cause-and-effect relationship - that indicated that trimethoprim can cause this problem.
Getting hold of a consultant surgeon can prove difficult, and the nature of the pecking order in hospitals makes the rest of their team very reluctant to go against their decisions unless there's a very good reason why; so I could not verbally share my input. The psychiatrists did get involved and the patient left the hospital on antipsychotic medication and with a warning to never never never ever take trimethoprim again.
I dutifuly filled in a yellow card for the reaction, but I remain skeptical about the role of the trimethoprim in this patient's case. In my opinion, it was innocent and this was a case of guilt by association.
