Quantitative study of controlled substance bedside wasting, disposal and evaluation of potential ecologic effects

Abstract

Drugs in wastewater arise from many sources. For health care, these include excretion and direct disposal (bedside wasting). The present study reports on the dispensing and wasting of 15 controlled substances (CS) at two health care facilities in Albany, NY over a nearly two year period. The study considered measures of ecotoxicity, drug metabolism, excretion and disposal of these CS. Potential alternatives to flushing of CS into wastewaters from healthcare facilities are discussed. Drug medication and waste collection records (12,345) included: numbers of drugs dispensed, returned and wasted. Overall, 8528 g of 15 CS were wasted. Three (midazolam, acetaminophen-codeine and fentanyl) accounted for 87.5% of the total wasted. Wasting varied by hospital, 14 CS at the academic medical center hospital and 8 at the surgical care center were wasted. Liquids were more frequently wasted than tablets or pills. Some combination drugs (acetaminophen (APAP)-codeine) were frequently (50% of drug dispensed) wasted while others were less wasted (APAP-hydrocodone-6.3%; APAP-oxycodone-1.3%). The 8 CS judged more hazardous to aquatic life were: APAP-codeine, APAP-hydrocodone, APAP-oxycodone, alprazolam, diazepam, fentanyl, midazolam, and testosterone. Ketamine, morphine, oxycodone and zolpidem were of lesser acute toxicity based on available LC50 values. These CS might provide a therapeutically equivalent alternative to the more environmentally harmful drugs. In health care facilities, professionals dispose of CS by bedside wasting into water or other receptacles. This can be avoided by returning CS to the hospital's pharmacy department, thence to a licensed distributor. Study of this process of drug wasting can identify opportunities for process improvements. We found 3 CS (APAP-codeine, midazolam and testosterone) where ½ to 1/3 of the drug was wasted and 5 others with 30 to 13% wasted. Knowledge of the adverse impacts from the release of highly toxic drugs into the environment might influence CS selection and disposal alternatives.