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RxPunge:
Pharmaceutical Waste Disposal System for HUP
Thalia Shamash ESE ‘09
Daniel Hillman ESE ’09
Ethan Keller ESE ‘09
Emily McGrath ESE ’09
GROUP #14
Advisor:
Dr. John Keenan
Abstract: There is a growing concern in the
medical and environmental communities
regarding the current disposal methods for
pharmaceutical waste. The practice of
discarding expired pills and intravenous
solutions in sink drains of hospitals
compromises the safety of our water and
environment. RxPunge has worked closely with
the inpatient pharmacy at the Hospital of the
University of Pennsylvania (HUP) to study the
IV waste system in place and to assist the
pharmacy in pioneering a new system to
properly classify, manage, and dispose of these
dangerous chemicals. RxPunge recorded
quantities and types of expired IV drug solutions
returned to the pharmacy to assess the current
system in place. Over 150 drugs were classified
and evaluated for hazard, reactivity,
biodegradation, and potential disposal methods.
Statistical distributions were identified to
simulate the drug disposal, and these were
used to develop a stochastic simulation to
predict the daily mix of pharmaceutical waste.
This model, combined with implementable
recommendations, depicts a method to better
manage pharmacy operations and reduce
hazardous waste. Inventory practices, drugpreparation times and distribution frequencies
can be modified to reduce drug waste from the
hospital and cut costs. Waste disposal and
treatment methods were analyzed, thereby
providing actionable options with which HUP
create positive environmental impact.
DEMO TIMES:
Thursday, April
23rd
2009
AM: 9:00, 9:30, 10:00
PM: 3:00
In thousands of medical facilities and millions of homes throughout the
country, medications are consumed on a daily basis. Hospitals generate
large quantities of medical waste, including biohazard, sharps, and others,
which are regulated and disposed of safely. A large gap exists with regard
to pharmaceutical waste that has not been explicitly designated as
hazardous.
This waste has been shown to cause harmful effects on natural
ecosystems. Furthermore, recent research has indicated that such
medications are present in natural and municipal water sources. In fact,
researchers with the U.S. Geological Survey have reported the presence
of various antibiotics just downstream of hospital and municipal
wastewater treatment plants in a number of states.
Two separate studies were conducted in which wasted
medications were meticulously documented:
I: RxPunge driven study ~ 11/21/08 – 12/14/08: Over 1,400
IV bags were processed twice a day. Analysis focused on drug
type, IV volume, and quantity of active drug. Data assisted with
formulation of drug categories and helping guide disposal and
treatment research.
II: HUP driven study ~ 2/24/09 – 3/16/09: Over 1100 IV bags
were recorded. Data contributed to understanding of IV
preparation times, expiration dates, and cost structure.
After the data collection, RxPunge categorized the drugs into
over 40 categories. Five of the most abundant categories
were chosen for analysis because of their large numbers and
adverse impacts. These were antibiotics, hormones,
vasoactive drugs, anti-seizure drugs, and antiviral drugs.
Drugs in the Environment:
Antibiotics
•Increase propagation of antibiotics-resistant bacteria strains
•Kill off healthy ecosystem bacteria and microbial algaes
Hormones
•Disturb endocrine systems, impair, and adversely effect biological
characteristics of humans and wildlife (e.g. feminized fish)
Data Findings:
•44% of the drugs recorded were antibiotics
•Top 5 categories of interest represent 67% of total drugs
recorded
•4% of containers collected are “hazardous” according to OSHA
•Highest drug waste occurs on weekends
•Critical Care units have the largest amount of waste
•Ten drugs account for 68% of waste costs
•70% of these drugs on average are administered to a patient
more than once a day
•50% have expiration dates longer than a day
Hormone
11%Vasoactive
Collaboration:
RxPunge conducted a careful review of regional hospitals, ultimately
choosing the Hospital of the University of Pennsylvania (HUP) as the most
appropriate partner. Reasoning included HUP’s stature as a cutting edge
hospital which pioneers industry standards in addition to the willingness of
key management to partners with Penn Engineering students.
Planning meetings with hospital management helped identify Intravenous
(IV) waste as the primary subject for analysis. RxPunge has since
developed a close relationship with directors of the Inpatient Pharmacy
and has conducted bi-weekly meetings on site.
The first stage in RxPunge’s analysis was to examine the current process
within HUP (as depicted in blue in the chart below). Key decision nodes
affecting waste output were identified (orange) as main components of a
potential RxPunge solution.
The Inpatient Pharmacy serves as a hub for storage, dispatch, and sorting
of pharmaceutical inventory. Medication solutions are mixed and sent out
to the floors. Drugs not administered to patients are returned to the
pharmacy during pick up rounds that occur twice a day. Upon return,
unexpired drugs are recycled, and expired medicines are poured into an
industrial sink in the IV processing room.
Drug
5%
Anti-seizure
4%
Antiviral
3%
Antibiotics
44%
Other
33%
Drug Quantities/day
Antibiotic
Vasoactive Drugs
Antiseizure Drugs
Hormones
Antiviral Drugs
Antibiotics
Disposal and Treatment:
A thorough review of Material Safety Data Sheets (MSDS) was
conducted in order to evaluate drug toxicity. Drugs were rated based
on flammability, solubility, environmental hazard and toxicity. These
parameters determine how expired drugs will be collected in
containers, mixed with other waste, and transported.
Waste disposal and treatment methods were analyzed, providing
actionable options with which HUP can mitigate its environmental
impact. Based on consultations and research, the most practical and
cost-efficient method of disposal is incineration. Potential incineration
sites in the Philadelphia area were identified, with costs, shipping
distances and safety features considered. The RxPunge model was
used to simulate expected waste volumes and then was employed to
determine collection frequency and receptacle size.
Other
200
180
160
140
120
100
80
60
40
Recommendations:
20
0
Date
The RxPunge Model:
This model depicts the current pharmacy waste output. Using
the collected data and sophisticated statistical software,
disposal distributions were backed-out to represent medication
categories that were returned to the pharmacy. Random
variables were generated according to these distributions.
Assumptions were made based on interviews with pharmacy
personnel. These data were used to simulate expected
dispatch, returns, and waste of various drug categories on a
given day.
Block diagram of process stages and locations for drug disbursement in HUP
Blue: Existing Process
Orange: Proposed Modifications
Drug Distributions:
Assumptions:
% drugs that go out a day are returned ~ N(30%, 2.5%)
% drugs that are returned are expired ~ N(30%, 5%)
1. RxPunge Inventory Solution:
a. Incorporating additional drug deliveries runs within HUP
b. Elimination of bulk preparation for uncommon drugs
c. Same day preparation to extend expiry time
d. Better enforcement of FIFO inventory management
Savings
27000
26000
Average Savings ($)
Authors:
Data Collection:
11
/2
1/
11 200
8
/2
2/
11 200
8
/2
3/
11 200
8
/2
4/
11 200
8
/2
5/
11 200
8
/2
6/
20
11
08
/3
0/
20
0
12
/1 8
/2
12 008
/2
/2
12 008
/4
/2
12 008
/5
/2
12 008
/6
/2
00
12
8
/7
/2
0
0
12
/8 8
/2
12 008
/9
/
12 200
8
/1
0/
12 200
8
/1
1/
20
12
08
/1
2/
12 200
8
/1
3/
12 200
8
/1
4/
2
2/ 008
24
/2
2/ 009
25
/2
2/ 009
26
/2
00
2/
27 9
/2
0
3/ 09
1/
20
3/ 09
3/
20
3/ 09
4/
20
3/ 09
5/
20
3/ 09
6/
20
09
3/
9/
20
09
3/
10
/2
3/ 009
11
/2
3/ 009
12
/2
3/ 009
13
/2
3/ 009
14
/2
00
9
Department of
Electrical and Systems
Engineering
Background:
Containers
University of Pennsylvania
25000
24000
23000
22000
21000
20000
0
2
4
Deliveries
6
8
2. RxPunge Disposal Solution:
a. Collection and categorization of expired drugs
b. Transportation to and incineration in 1 of 3 identified waste
management sites
c. Collection of waste from outside management once per month
d. While currently infeasible, sewage treatment will provide a more
comprehensive solution in the future.