Postoperative Pain Management With a Patient-Controlled Transdermal Delivery System for Fentanyl

Peter J. S. Koo

Am J Health Syst Pharm. 2005;62(11):1171-1176.

Description

Fentanyl hydrochloride PCTS is a needle-free, credit-card-sized device that delivers analgesics by iontophoresis (Figure 1). When the system is activated by the patient pressing a recessed button twice in three seconds, an imperceptible, low-intensity electric current generated by a battery housed within the system transfers fentanyl from a hydrogel reservoir across the skin and into the systemic circulation. The unit has an adhesive backing and is placed either on the upper outer arm or on the chest. The system is self-contained; therefore, in contrast to i.v. PCA, additional materials, such as tubing, pumps, and power cables, are not necessary for operation. When the button is pressed on the self-contained PCTS device, an audible beep and a red light from a light-emitting diode (LED) indicate that delivery of a dose has been initiated. The system is preprogrammed to deliver a 40-µg fentanyl hydrochloride dose over a 10-minute period. Patients can initiate up to six doses per hour for up to 24 hours from the time the first dose was initiated or a maximum of 80 doses, whichever occurs first. At that point, the unit will no longer generate the electric current necessary for drug delivery and becomes unresponsive to additional requests for medication. It should be removed and replaced with a new system if continued PCA is indicated. A system-initiated lockout prevents the patient from activating the system for additional drug during the 10-minute delivery period. This delivery period is preprogrammed by the manufacturer; administration cannot be accelerated or extended beyond the 10-minute interval. After each dose is delivered, the LED flashes to indicate the cumulative number of doses the patient has received, with each flash signifying delivery of a range of five doses (one flash = 1-5 doses delivered, two flashes = 6-10 doses, etc.).

(Enlarge Image)

Fentanyl hydrochloride patient-controlled transdermal system. The unit weighs 15 g and is 3.3 in long, 1.9 in wide, and 0.39 in high. Reprinted with permission from Ortho-McNeil.

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Cite this: Postoperative Pain Management With a Patient-Controlled Transdermal Delivery System for Fentanyl - Medscape - Jun 01, 2005.

Pharmacokinetics of Fentanyl Hydrochloride Delivered by Patient-Controlled Transdermal System After Single- and Multiple-Day Dosing ^a
Pharmacokinetic Variable^b	After One Day ( n = 25)	After Three Days ( n = 25)	p
C _max (µg/L)	0.30	0.48	0.0001
t _max (hr)	1.66	1.33	--
t (hr)	11.4	14.2	0.0001
AUC_0-5 (µg•hr/L)	1.20	1.88	0.0001
C _pre (µg/L)	0.21	0.34	0.0001
Corrected AUC_0-5 (µg•hr/L)	0.40	0.54	0.133

^aAdapted from reference 30, with permission.

^b C _max = maximum concentration; t _max = time to C _max; t = half-life; AUC_0-5 = area under the concentration-versus- time curve from zero to five hours; C _pre = predose concentration.

Effect of Subject Demographics on AUC _0-∞ ^a
Demographic Characteristic	n	Least-Squares Mean ± S.E.	Mean ± S.E. Difference	95% Confidence Interval	p
Race			-0.300 ± 1.560	-3.428 to 2.828	0.848
Black	28	2.98 ± 0.92
White	36	3.28 ± 1.08
Age (yr)			1.447 ± 1.467	-1.495 to 4.389	0.328
18-45	39	3.85 ± 0.75
>65	25	2.41 ± 1.15
Build			1.140 ± 1.279	-1.425 to 3.705	0.377
Lean	31	3.70 ± 0.98
Obese	33	2.56 ± 0.81
Sex			1.201 ± 1.577	-1.963 to 4.364	0.450
Female	27	3.73 ± 1.03
Male	37	2.53 ± 0.99

^aReproduced from reference 31, with permission. AUC_0-∞= area under the concentration-versus-time curve from zero hours to infinity.

Table 3. Secondary Efficacy Endpoints for Largest Placebo-Controlled Studies Comparing Fentanyl Hydrochloride Patient-Controlled Transdermal System (PCTS) With Placebo ^a
Endpoint	PCTS ( n = 235)	Placebo ( n = 204)	p
No. pts. withdrawing from study for any reason (%)	81 (34.5)	128 (62.7)	<0.0001
No. pts. with successful pain control (%)^b
PGA	179 (76.2)	106 (52.0)	<0.0001
IGA	176 (74.9)	107 (52.5)	<0.0001

^aData on file, ALZA Corp., Mountain View, CA, protocol C2001-011.

^bSuccessful pain control = a rating of pain control as excellent or good. PGA = patient global assessment, IGA = investigator global assessment.

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