Question

Describe how an advanced practice nurse would alter the medication dose of Bactrim in a patient with chronic kidney disease. Discuss the physiologic rationale for altering the dose and monitoring its effectiveness.

Answer 1

Bactrim is a combination of two antibiotics namely sulfamethoxazole and trimethoprim . It is used to treat wide variety of bacterial infections like ear infections, pneumonia,urinary tract infections, intestinal infections .

Renal diseases delays the elimination of antibiotic from the body and thus the dosage has to be adjusted according to the creatinine clearance.

If the creatinine clearance is less than 10 mL/min then the bactrim dose is adjusted to

15 - 20 mg/kg /dose before dialysis.

7 - 10 mg/kg/dose after dialysis.  

If Creatinine clearance is between 10 mL/min and 30 mL/min then 50% of normal dose is reduced .

If creatinine clearance is 30mL/min , no need to adjust the dose of bactrim.

PHYSIOLOGIC REASON TO ADJUST THE DOSE IN CHRONIC KIDNEY DISEASE :

Most of the drugs are eliminated through the kidneys . If there is chronic kidney disease, the filtration process is impaired which causes accumulation of the certain drugs which becomes toxic to our body. Thus , dose is altered according to the creatinine clearance and other renal parameters.

The effectiveness of the antibiotic is measured according to the reduction in signs and symptoms of the bacterial disease for which the bactrim was started.

Thank you.