• Three new fentanyl products have recently become available
for the relief of breakthrough pain associated with cancer. All
involve novel modes of delivery for fentanyl with two providing
oramucosal delivery via sublingual (Abstral®) and buccal routes
(Effentora®), and one providing mucosal delivery via the
intranansal route (Instanyl®).

• The evidence base supporting their efficacy is generally poor.
Few studies have been published, most comparisons are
against placebo, and methodological and protocol faults have
been identified. However, they do appear to produce
meaningful and relatively rapid analgesia.

• As with evidence of efficacy, evidence for safety is also poorly
available. No important specific safety concerns were
highlighted in the clinical studies except for mouth ulceration
due to the buccal tablet formulation.

• However, each product is associated with complicated initiation,
titration, and maintenance dose instructions. It is not possible to
transfer patients from an alternative product/drug to one of the
new products without re-titration of the dose. Concerns have
been raised regarding the suitability of such products for wider
use outside of specialist care where observation may not be as
intense and where prescribers will be less familiar with these
products. Fentanyl is associated with a relatively high incidence
of adverse effects and treatment complications.

• Most episodes of breakthrough pain are currently managed with
oral morphine solution, although for some patients the onset of
analgesia may be too slow to produce meaningful and timely
analgesia. However, morphine solution still appears to be an
effective product for most patients, and it is one of the least
costly strong opioids suitable for breakthrough pain relief at less
than £1 per episode. The new fentanyl products all cost
between £5 and £6 per dose and evidence indicates that a
second dose or additional analgesia is often required for an
episode of breakthrough pain.