Page 210 Acute Pain Management

efficacy; nasal irritation, congestion and bad taste have been reported with the short‐term
use of butorphanol and pethidine (Dale et al, 2002).
Technical problems with pumps have been reported in up to 10% of cases and dispensing
issues for techniques such as PCINA, which could allow ready and unauthorised access to the
drugs, have not been addressed (Dale et al, 2002).
Other analgesic drugs
IN ketamine has been shown to provide relatively rapid onset of effective pain relief (within
15 minutes); any adverse effects were mild and transient (Christensen et al, 2007 Level II).
IN ketorolac has also been shown to be effective; after major surgery 30 mg but not 10 mg
IN ketorolac resulted in significant opioid‐sparing over 20 hours and better pain relief in the
first 6 hours after surgery (Moodie et al, 2008 Level II).

6.6.2 Sublingual and buccal routes
When analgesic drugs are administered by the sublingual or buccal routes, their efficacy will
in part depend on the proportion of drug swallowed.
Opioids
Sublingual buprenorphine, given as a tablet, has an overall bioavailability of 30% to 50%
(Mendelson et al, 1997; Kuhlman et al, 1996) and a long duration of action (mean half‐life
28 hours) (Kuhlman et al, 1996). Sublingual buprenorphine 0.4 mg was found to be as effective
as 10 mg morphine IM (Cuschieri et al, 1984 Level II) and 75 mg pethidine IM after abdominal
surgery (Moa & Zetterstrom, 1990 Level II).
CHAPTER 6 on a stick and is available in a range of doses from 200 to 1600 mcg. Overall, the bioavailability
Oral transmucosal fentanyl citrate (OTFC) incorporates fentanyl into a flavoured solid lozenge

of OTFC is about 52% compared with IV fentanyl, with peak blood levels achieved in
22 ± 2.5 minutes (Streisand et al, 1991 Level IV). The median time to onset of analgesia was
about 5 minutes and the relative potency compared with IV morphine was 8–14:1. (Lichtor et
al, 1999 Level II).
In many countries, regulatory authorities have specifically noted that OTFC must not be used
in opioid‐naïve patients or in the management of acute and postoperative pain: approval is
limited to the management of break‐through pain in patients who are opioid‐tolerant (FDA,
2007; MIMS, 2008; eCompendium, 2008).
Only a few studies have investigated the postoperative use of OTFC. It was found to be an
effective analgesic after orthopaedic (Ashburn et al, 1993 Level II) and abdominal surgery (Lichtor
et al, 1999 Level II) and during burns wound care (Sharar et al, 1998 Level II; Sharar et al, 2002
Level II). Pain relief at 15 minutes in children with lower extremity injuries was the same with
IV bolus doses of morphine and OTFC, but lower with OTFC after that until the end of the
75 minute study period (Mahar et al, 2007 Level II).
However, because of the risk of achieving high peak plasma levels with unsupervised
administration, the limited data available, and the specific lack of approval for use in opioid‐
naïve patients, OTFC cannot be recommended for the management of acute pain.
Fentanyl buccal tablets (FBT) use an effervescent drug delivery technology that enables more
rapid absorption and delivery of a larger proportion of the fentanyl dose compared with OTFC
(Darwish et al, 2006; Darwish et al, 2007). They were effective in opioid‐tolerant patients for the
treatment of breakthrough cancer pain (Portenoy et al, 2006 Level II; Slatkin et al, 2007 Level II),
chronic low back pain (Portenoy et al, 2007 Level II) and chronic neuropathic pain (Simpson et al,
2007 Level II). At present, this formulation is also not approved for use in the acute pain setting.

162 Acute Pain Management: Scientific Evidence