Safety of fentanyl initiation according to past opioid exposure among patients newly prescribed fentanyl patches

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Figure 1:
Proportion of patients newly prescribed fentanyl patches, 2001–2012, by level of previous opioid exposure (% of recommended opioid dose in the 60 days before fentanyl initiation). Previous opioid use ranged from 0% (no opioid history) to ≥ 100% (safe initiation of fentanyl). The vertical dashed lines represent when warnings or advisories were issued by the US Food and Drug Administration (a and f),11^,12 Health Canada (b and i),13^,18 the Institute for Safe Medication Practices Canada (d, e, h and j)14^–17 and professional journals (c and g).19^,20

Table 1:

Characteristics of patients newly prescribed the fentanyl patch, 2001–2012

Characteristic	No. (%) n = 11 063
Sex
Female	6884 (62.2)
Male	4179 (37.8)
Age group, yr
≤ 64	4692 (42.4)
65–74	1894 (17.1)
75–84	2500 (22.6)
≥ 85	1977 (17.9)
Initial dose of fentanyl patch, μg/h
12	1293 (11.7)
25	7739 (70.0)
50	1459 (13.2)
75	363 (3.3)
100	209 (1.9)
Prior opioid exposure^*
Single-entity LA opioid	2956 (26.7)
Single-entity IR opioid	1889 (17.1)
Oxycodone/acetaminophen	1289 (11.7)
Codeine/acetaminophen	2406 (21.7)
No exposure	2523 (22.8)

Note: IR = immediate release, LA = long acting.
↵* Mutually exclusive groups of patients categorized by highest to lowest level of opioid used in the 90 days preceding the first fentanyl patch prescription (highest = single-entity LA opioid; lowest = codeine/acetaminophen combination).

Table 2:

Safety of fentanyl initiation at the start and end of the study period, by sex and age

Characteristic	% (no.) of patients with unsafe fentanyl initiation^*
Characteristic	2001 n = 866	2012 n = 574	Overall n = 11 063
Sex
Female	87.4 (501/573)	53.1 (178/335)	76.3 (5 253/6 884)
Male	86.0 (252/293)	45.6 (109/239)	70.4 (2 943/4 179)
Age group, yr
≤ 64	79.0 (233/295)	45.9 (119/259)	66.1 (3 100/4 692)
65–74	86.3 (126/146)	41.7 (48/115)	72.7 (1 377/1 894)
75–84	89.4 (210/235)	52.3 (58/111)	81.6 (2 039/2 500)
≥ 85	96.8 (184/190)	69.7 (62/89)	85.0 (1 680/1 977)
All	87.0 (753/866)	50.0 (287/574)	74.1 (8 196/11 063)

↵* Unsafe = fentanyl patch newly prescribed to patient without adequate prior exposure to opioids.

Table 3:

Distribution of patients according to initial fentanyl dose and prior opioid exposure

Prior opioid exposure, mg/d of oral morphine equivalent	Initial fentanyl patch dose, μg/h; no. (%) of patients^*
Prior opioid exposure, mg/d of oral morphine equivalent	12 n = 1293	25 n = 7739	50 n = 1459	75 n = 363	100 n = 209	Total n = 11 063
No exposure	301 (10.4)	2276 (78.3)	248 (8.5)	51 (1.8)	31 (1.1)	2907
1–29	429 (13.9)	2287 (73.9)	315 (10.2)	47 (1.5)	16 (0.5)	3094
30–59	308 (15.7)	1382 (70.4)	223 (11.4)	38 (1.9)	13 (0.7)	1964
60–179	215 (10.3)	1412 (67.6)	358 (17.1)	77 (3.7)	27 (1.3)	2089
180–269	18 (4.4)	191 (46.7)	134 (32.8)	43 (10.5)	23 (5.6)	409
270–359	9 (4.8)	71 (37.8)	57 (30.3)	40 (21.3)	11 (5.9)	188
≥ 360	13 (3.2)	120 (29.1)	124 (30.1)	67 (16.3)	88 (21.4)	412