(HealthNewsDigest.com) – CORVALLIS, Ore. – Pharmacists at Oregon State University have developed a new approach to developing drug dosages for patients with chronic kidney disease that shows promise for improving the therapeutic value of drugs while minimizing adverse effects.
The process, which provides a systematic analysis of the complex interplay among biological, chemical and pharmaceutical processes in the patient’s body, was created by Ali Olyaei, a professor in the OSU College of Pharmacy, who also has an appointment at Oregon Health and Science University.
“Chronic kidney disease (CKD) can affect nearly every organ system in the body,” said Olyaei, who specializes in renal and transplant medicine at the OSU/OHSU Division of Nephrology and Hypertension in Portland. “Patients with CKD require a careful and thorough evaluation when medications are being prescribed.”
Patients with chronic kidney disease face significantly greater risks from medications than patients with normal kidney function – as much as three times higher, according to researchers at OSU. Kidney disease compromises the body’s ability to absorb, metabolize and eliminate drugs. Compounding the dangers are the multiple health problems that often accompany kidney disease.
Because of that complexity, it is important to both assess properties of all medications, and to examine specific patient characteristics. This “can help to ensure outcomes while lowering the risk for toxicity,” said Olyaei in the current issue of the journal Blood Purification.
Impaired renal function can cause drugs to build up to toxic levels in a patient’s system or, on the other end of the spectrum, to pass through the body unused or underused – what Olyaei called “underdosing.” Add to those risks the 11 medications chronic kidney patients take on average, and harmful drug interactions become a serious concern.
“Studies have shown an increase in mortality in patients with CKD as the number of medications prescribed increase,” said Olyaei.
Among the myriad factors that should be considered in dosing and prescribing are: replacement doses for patients undergoing dialysis; impaired functioning of other organs such as the heart, liver and gastrointestinal system; absorption rates of drugs administered by mouth, injection or IV; monitoring for toxic accumulation and adequate therapeutic levels; fluid balance in the body; gender and muscle mass.
While Olyaei provides a set of formulas for calculating proper dosages, he cautioned that wide patient variability makes the task as much an art as it is a science. Pharmacological management of patients with CKD is “imprecise” and requires critical judgment along with the math and lab results, he noted.
“Chronic kidney disease is increasing at an alarming rate,” Olyaei said. “Medication prescribing in this growing population is especially difficult. By applying a quantitative approach, health care providers can improve pharmacotherapeutic outcomes while reducing adverse drug reactions.”