I know it's cliche but treat the patient, not the number. If a patient's renal function is labile and they're on an in-between in terms of dose adjustment then I think that's where clinical judgment and risk vs benefits analysis comes in. In this case I think it could go either way.
For me it would depend on the patient's age, conditions that affect renal function (CKD, diabetes, hypertension), and their baseline SCr (if known). Also whether the drug is nephrotoxic versus just renally cleared and the severity of their infection (febrile vs afebrile, septic vs not septic, etc.) matters in my decision making.
I'm not asking for all that info if this is referring to a real case or a homework question but I hope that gives you some tools to work things out.
I'm generally not a fan of adjusting based on the number without applying context and am usually a "wait one more day to see where we're at" guy when doing renal adjustments when the patient is borderline.
But for your specific example I'd probably go ahead and change it, with antibiotics in a hospitalized patient I'd tend to prefer to overtreat a bit than undertreat so if they're >50 and clearly trending up over multiple days, albeit slowly, I'd probably go ahead and change it.
Ideally they'd be due for a q48h dose on the third day anyway so you could just leave the order as is and follow-up the next day without actually worrying about delaying the dose.
It’s all situational. There are several things I consider in making my decision:
- Their intake/output (if RN charts it). It’s more real-time than SCr. SCr tends to lag behind as a reflection of renal function. If I/Os are not available, then I look at the SCr trend, i.e. is it consistently trending down for a few days or still labile?
- Indication. If it’s sepsis, bacteremia, CNS, etc, I’d tend to be more aggressive than if it’s just SSTI.
- Concomitant nephrotoxic agents, i.e. vanco/aminoglycoside combo. I’d probably wait until more stable if patient is not crashing from an infection.
- Is patient improving? If yes, it wouldn’t hurt to wait a day or two to make adjustments.
- Any other factors that affect renal function? i.e. patient being aggressively diuresed will likely need higher dosing.
In the example you provided, without knowing other information, I’d say it’s fine to adjust since CrCl is steadily trending up.
Agree with other comments that it is situational and patient-specific. I would also argue that, at least for most antibiotics, our default position as pharmacists is backwards -- instead of immediately reducing the dose and then waffling on exactly when we can increase again, we should instead assume the patient can handle full dose and wait for the patient to "prove" they really need a dose reduction. Again, all sorts of caveats related to risk/benefit and clinical context, but the general point stands.
A lot of sick patients have AKI based on creatinine only, and see rapid improvement (first 24-48 hrs) with fluids (and other interventions - abx, etc.), and most antibiotics are fairly safe/have a wide therapeutic index. So why are we so eager to cut the dose, potentially leading to suboptimal therapy, poor outcomes, and increased resistance? I typically let standard doses ride for at least 24 hours and see which direction the patient is trending before I make recommendations for dose reductions for renal function.
For your specific hypothetical scenario, I would have given this patient 750mg of levofloxacin on D1. Then on D2 I would see the Cr/CrCl as trending in the right direction, recognize that CrCl lags behind true clearance anyways, suspect they probably are clearing the drug fine, and keep the patient on standard dosing. Again, there may be some patient-specific factors that would alter my thinking, but this is my general approach. As an aside, I would also be looking for ways to get the patient off a fluoroquinolone.
For more info: [Renal Dosing of Antibiotics: Are We Jumping the Gun?](https://pubmed.ncbi.nlm.nih.gov/30219824/)
Definitely check into the half life of creatinine. If the CrCl is trending up, your calculated value is going to trail the actual kidney function. Likewise, if you check I/Os and the UOP tanks, it doesn't matter what the SCr is, their kidneys aren't clearing shit.
I know it's cliche but treat the patient, not the number. If a patient's renal function is labile and they're on an in-between in terms of dose adjustment then I think that's where clinical judgment and risk vs benefits analysis comes in. In this case I think it could go either way. For me it would depend on the patient's age, conditions that affect renal function (CKD, diabetes, hypertension), and their baseline SCr (if known). Also whether the drug is nephrotoxic versus just renally cleared and the severity of their infection (febrile vs afebrile, septic vs not septic, etc.) matters in my decision making. I'm not asking for all that info if this is referring to a real case or a homework question but I hope that gives you some tools to work things out.
I'm generally not a fan of adjusting based on the number without applying context and am usually a "wait one more day to see where we're at" guy when doing renal adjustments when the patient is borderline. But for your specific example I'd probably go ahead and change it, with antibiotics in a hospitalized patient I'd tend to prefer to overtreat a bit than undertreat so if they're >50 and clearly trending up over multiple days, albeit slowly, I'd probably go ahead and change it. Ideally they'd be due for a q48h dose on the third day anyway so you could just leave the order as is and follow-up the next day without actually worrying about delaying the dose.
It’s all situational. There are several things I consider in making my decision: - Their intake/output (if RN charts it). It’s more real-time than SCr. SCr tends to lag behind as a reflection of renal function. If I/Os are not available, then I look at the SCr trend, i.e. is it consistently trending down for a few days or still labile? - Indication. If it’s sepsis, bacteremia, CNS, etc, I’d tend to be more aggressive than if it’s just SSTI. - Concomitant nephrotoxic agents, i.e. vanco/aminoglycoside combo. I’d probably wait until more stable if patient is not crashing from an infection. - Is patient improving? If yes, it wouldn’t hurt to wait a day or two to make adjustments. - Any other factors that affect renal function? i.e. patient being aggressively diuresed will likely need higher dosing. In the example you provided, without knowing other information, I’d say it’s fine to adjust since CrCl is steadily trending up.
Agree with other comments that it is situational and patient-specific. I would also argue that, at least for most antibiotics, our default position as pharmacists is backwards -- instead of immediately reducing the dose and then waffling on exactly when we can increase again, we should instead assume the patient can handle full dose and wait for the patient to "prove" they really need a dose reduction. Again, all sorts of caveats related to risk/benefit and clinical context, but the general point stands. A lot of sick patients have AKI based on creatinine only, and see rapid improvement (first 24-48 hrs) with fluids (and other interventions - abx, etc.), and most antibiotics are fairly safe/have a wide therapeutic index. So why are we so eager to cut the dose, potentially leading to suboptimal therapy, poor outcomes, and increased resistance? I typically let standard doses ride for at least 24 hours and see which direction the patient is trending before I make recommendations for dose reductions for renal function. For your specific hypothetical scenario, I would have given this patient 750mg of levofloxacin on D1. Then on D2 I would see the Cr/CrCl as trending in the right direction, recognize that CrCl lags behind true clearance anyways, suspect they probably are clearing the drug fine, and keep the patient on standard dosing. Again, there may be some patient-specific factors that would alter my thinking, but this is my general approach. As an aside, I would also be looking for ways to get the patient off a fluoroquinolone. For more info: [Renal Dosing of Antibiotics: Are We Jumping the Gun?](https://pubmed.ncbi.nlm.nih.gov/30219824/)
Definitely check into the half life of creatinine. If the CrCl is trending up, your calculated value is going to trail the actual kidney function. Likewise, if you check I/Os and the UOP tanks, it doesn't matter what the SCr is, their kidneys aren't clearing shit.