15
the possibility of an allergic reaction to the materials in the
device (See Silicone Information).
Antibiotic Information
The antibiotics present in InhibiZone, minocycline and rifampin
(rifampicin), are well characterized and have been in use for
years. The dosage present on the artificial urinary sphincter is
intended to act on organisms that attempt to colonize on the
device.
The amount of antibiotics on individual components and
number of components implanted may vary. The average
amounts of rifampin and minocycline contained on a prosthesis
implant are represented by the means and 95% tolerance
intervals of the following implant configurations:
1.9 mg rifampin (0.7 – 3.1 mg) and 2.8 mg minocycline (2.1
– 3.5 mg) for the implant configuration with the lowest drug
levels, i.e., single 4.0 cm cuff + control pump.
3.7 mg rifampin (0.9 – 6.5 mg) and 6.3 mg minocycline (4.7
– 8.0 mg) for the implant configuration with the highest drug
levels, i.e., double 11.0 cm cuff + control pump.
The following in vitro data are available, but their clinical
significance is unknown. No clinical studies have been performed
to evaluate the effect of the antibiotic surface treatment on
reducing the incidence of artificial urinary sphincter implant
infections.
Table 6: In vitro Zone of Inhibition for Device Samples*
with InhibiZone Treatment
Organism
Mean (mm)
S.D. (mm)
Number of Isolates
Staphylococcus epidermidis
22.6
2.9
21
Staphylococcus aureus
17.5
5.0
25
Escherichia coli**
6.5
2.6
24
Enterococcus faecalis**
4.8
6.7
21
Candida albicans**
0.1
0.4
21
Proteus mirabilis**
0.6
1.0
17
* obtained using standardized KRT test samples containing approximately 12µg
minocycline and 26 µg rifampin (rifampicin)
** the isolates tested were not susceptible to rifampin (rifampicin) and/or minocycline
control disks
An animal infection study was conducted using 11 rabbits. Five
rabbits were implanted subcutaneously with 6 test samples each
and five rabbits were implanted subcutaneously with 6 control
samples each. One rabbit received three test samples and three
control samples. The test samples were portions of an InhibiZone
treated AMS 700 pump and the control samples were portions
of a standard AMS 700 pump without InhibiZone. The AMS
700 Pumps used in the 700 Series of Inflatable Penile Prostheses
is similar to AMS 800 Pumps used in the 800 Series of Artifical
Urinary Sphincters in regards to material composition, adhesive,
and InhibiZone application process. All samples were soaked in
a 10
3
-10
4
CFU solution of staphylococcus aureus, Sheretz strain
for 8 hours. Samples were then allowed to dry for 30 minutes
prior to surgical placement in the rabbit. After 2 days, all
samples were removed and observed for growth on the samples.
The number of coated samples that were infected was statistically
significantly lower than the number of control samples that were
infected.
Silicone Information
This device is composed of a number of materials, including
solid silicone elastomers and a fluorosilicone lubricant. Silicone
gel is not a component in the materials of this device.
