My mother's current round of return trips to hospital confiment has led me to question whether the dosage of drugs she has been receiving is appropriate for her profile - short, thin Asian elderly woman in her 90s, and I have started to look at how the hospital doctors estimate the GFR of patients to arrive at the dosage rate of drugs being administered.
I got into looking at this because I was perplexed at how her mental condition took a dive - insomnia, restlessness, disorientation, drowsiness, not eating and drinking, etc. - and this was never explained by the doctors except pointing to her old age as a cause and making her condition a fait accompli, so that we could start accepting putting her on pallative care or on a hospice. It seemed so very convenient. And I was prepared to accept that.
Luckily, a psychiatrist whom I requested for to diagnose my mom, prior to her discharge, was very helpful. He pointed out to the administration of a fluoroquinolone-based antibiotic called Levofloxacin, and said that she could be experiencing the side effects. My mom was discharged, and I was hoping the side effect would go away in a few days. But it never did. And my mom was readmitted having eaten and having drank so little to the point that her blood pressure plunged. She was dehydrated and IV was administered and she was given an antibiotic again to help her through the stressful period.
It was then that I started to look further into Levofloxacin, and what my searches revealed was that there is a long trail leading to Levofloxacin and its ilk, of side effects that are so severe and long-lasting that would affect the nervous system, as well as tendons.
I started asking why this drug was used on my frail mother, given that it has such a long history of lingering and debilitating side effects, that enough complaints had been made by consumers in the US leading to the FDA issuing a "black box warning" on the labels, which is the highest level the FDA can give before a product is pulled out of the market. The picture would not be complete without my mentioning that over the years many antibiotics of the fluoroquinolone class had been pulled off the market. This should give any well-meaning doctor enough pause when considering giving anybody, much less a frail elderly woman, such a drug.
But any mention of the side effect to the doctors in the hospital I'm in contact with would be met with dismissive trivializing with statements such as "anything is possible." That really got my ire, as they have the gall to equate something highly probable to being something on the level of "anything is possible." Well, the sun may sink today. That is possible. But no one should worry about it, right?
I then got the information packet, the sheet of thin paper with very small fonts that explains everything on the the use of the drug Levofloxacin. It also showed me how dosage levels are determined, and it is determined by the estimated glomerular filtration rate (eGFR), which is related to how well the kidney filters blood going through it.
The choice of formula on estimating the eGFR determines largely, if not solely, the dosage rate of the drug.
On the information sheet that came with the Levofloxacin IV fluid bottle, it gave me a formula, called the Cockcroft-Gault, which I used to determine the eGFR, which came out to be a value of 18 ml/min. With this value, I would look at a table that would show me that my mom would need to dosed with 250mg of the drug daily.
However, when I asked the doctor who administered the drug how he arrived at a dosage that's twice the rate I had determined above, he told me that he is using the CKD-EPI formula, which he justified using at the literature shows that his formula is superior to the formula I used.
His eGFR using CKD-EPI came out to 32 ml/min, which almost twice the eGFR value under Cockcroft-Gault at 18 ml/min. Under his eGFR value, he was fully justified in using the 500mg daily dosage rate.
I looked at the literature again in the internet, and I could not find anything to refute him.
Certainly, the best way to prove him wrong is to take an actual GFR value by taking a day's worth of urine, and running it through some tests to determine the actual GFR. But that would be hard to do, given my mom suffers incontinence, and wearing diapers means it's harder to collect urine.
But what if the study or studies that had conclusions stating CKD-EPI as being superior is biased by pharma? Certainly pharma companies have incentive to pump up the eGFR values in order to double the dosage rate, so that its sales would double. Is there any literature out there that I'm not privy to that could refute the generally held idea that the CKD-EPI method is superior than all the rest of the eGFR formulas, especially for the subset of elderly population to which my mom belongs?
I got into looking at this because I was perplexed at how her mental condition took a dive - insomnia, restlessness, disorientation, drowsiness, not eating and drinking, etc. - and this was never explained by the doctors except pointing to her old age as a cause and making her condition a fait accompli, so that we could start accepting putting her on pallative care or on a hospice. It seemed so very convenient. And I was prepared to accept that.
Luckily, a psychiatrist whom I requested for to diagnose my mom, prior to her discharge, was very helpful. He pointed out to the administration of a fluoroquinolone-based antibiotic called Levofloxacin, and said that she could be experiencing the side effects. My mom was discharged, and I was hoping the side effect would go away in a few days. But it never did. And my mom was readmitted having eaten and having drank so little to the point that her blood pressure plunged. She was dehydrated and IV was administered and she was given an antibiotic again to help her through the stressful period.
It was then that I started to look further into Levofloxacin, and what my searches revealed was that there is a long trail leading to Levofloxacin and its ilk, of side effects that are so severe and long-lasting that would affect the nervous system, as well as tendons.
I started asking why this drug was used on my frail mother, given that it has such a long history of lingering and debilitating side effects, that enough complaints had been made by consumers in the US leading to the FDA issuing a "black box warning" on the labels, which is the highest level the FDA can give before a product is pulled out of the market. The picture would not be complete without my mentioning that over the years many antibiotics of the fluoroquinolone class had been pulled off the market. This should give any well-meaning doctor enough pause when considering giving anybody, much less a frail elderly woman, such a drug.
But any mention of the side effect to the doctors in the hospital I'm in contact with would be met with dismissive trivializing with statements such as "anything is possible." That really got my ire, as they have the gall to equate something highly probable to being something on the level of "anything is possible." Well, the sun may sink today. That is possible. But no one should worry about it, right?
I then got the information packet, the sheet of thin paper with very small fonts that explains everything on the the use of the drug Levofloxacin. It also showed me how dosage levels are determined, and it is determined by the estimated glomerular filtration rate (eGFR), which is related to how well the kidney filters blood going through it.
The choice of formula on estimating the eGFR determines largely, if not solely, the dosage rate of the drug.
On the information sheet that came with the Levofloxacin IV fluid bottle, it gave me a formula, called the Cockcroft-Gault, which I used to determine the eGFR, which came out to be a value of 18 ml/min. With this value, I would look at a table that would show me that my mom would need to dosed with 250mg of the drug daily.
However, when I asked the doctor who administered the drug how he arrived at a dosage that's twice the rate I had determined above, he told me that he is using the CKD-EPI formula, which he justified using at the literature shows that his formula is superior to the formula I used.
His eGFR using CKD-EPI came out to 32 ml/min, which almost twice the eGFR value under Cockcroft-Gault at 18 ml/min. Under his eGFR value, he was fully justified in using the 500mg daily dosage rate.
I looked at the literature again in the internet, and I could not find anything to refute him.
Certainly, the best way to prove him wrong is to take an actual GFR value by taking a day's worth of urine, and running it through some tests to determine the actual GFR. But that would be hard to do, given my mom suffers incontinence, and wearing diapers means it's harder to collect urine.
But what if the study or studies that had conclusions stating CKD-EPI as being superior is biased by pharma? Certainly pharma companies have incentive to pump up the eGFR values in order to double the dosage rate, so that its sales would double. Is there any literature out there that I'm not privy to that could refute the generally held idea that the CKD-EPI method is superior than all the rest of the eGFR formulas, especially for the subset of elderly population to which my mom belongs?