General Information

Abstral is a sublingual tablet formulation of fentanyl citrate, a potent opioid analgesic. The precise mechanism of the analgesic action is unknown.

Abstral is specifically indicated for the management of breakthrough pain in cancer patients 18 years of age and older who are already receiving, and who are tolerant to, opioid therapy for their underlying persistent cancer pain.

Abstral is supplied as a sublingual tablet designed for oral administration. The recommended initial dose of the drug is a single 100 mcg tablet. If adequate analgesia is obtained within 30 minutes of administration of the 100 mcg tablet, continue to treat subsequent episodes of breakthrough pain with this dose. If adequate analgesia is not obtained after the initial dose, the patient may use a second Abstral dose (after 30 minutes) as directed by their health care provider. No more than two doses of Abstral may be used to treat an episode of breakthrough pain. Patients must wait at least 2 hours before treating another episode of breakthrough pain. The Abstral dose should be escalated in a stepwise manner, increased by 100 mcg multiples up to 400 mcg, over consecutive breakthrough episodes until adequate analgesia with tolerable side effects is achieved.

Clinical Results

FDA Approvals
The FDA approval of Abstral was based on a double-blind, placebo-controlled, crossover study in 131 subjects experiencing breakthrough cancer pain. Breakthrough cancer pain was defined as a transient flare of moderate-to-severe pain occurring in patients experiencing persistent cancer pain otherwise controlled with maintenance doses of opioid medications. Of the 131 subjects who entered the titration phase of the study, 78 (60%) achieved a successful dose during the titration phase. Sixty-six patients entered the double-blind phase and 60 completed the study. The primary outcome measure, the mean sum of pain intensity difference at 30 minutes (SPID30) for Abstral-treated episodes was statistically significantly higher than for placebo-treated episodes. In a second open-label safety study using an identical titration regimen, 96 of 139 patients (69%) who entered the study titrated to a dose in which the patient obtained adequate analgesia with tolerable side effects during the titration phase.

Mechanism of Action

Abstral is a sublingual tablet formulation of fentanyl citrate, a potent opioid analgesic. The precise mechanism of the analgesic action is unknown although fentanyl is known to be a µ-opioid receptor agonist. Specific CNS opioid receptors for endogenous compounds with opioid-like activity have been identified throughout the brain and spinal cord and play a role in the analgesic effects of this drug.

Literature References

Lennernäs B, Frank-Lissbrant I, Lennernäs H, Kälkner KM, Derrick R, Howell J Sublingual administration of fentanyl to cancer patients is an effective treatment for breakthrough pain: results from a randomized phase II study. Palliative Medicine 2010 Apr;24(3):286-93. Epub 2009 Dec 16

Rauck RL, Tark M, Reyes E, Hayes TG, Bartkowiak AJ, Hassman D, Nalamachu S, Derrick R, Howell J Efficacy and long-term tolerability of sublingual fentanyl orally disintegrating tablet in the treatment of breakthrough cancer pain. Current Medical Research and Opinion 2009 Dec;25(12):2877-85

Lennernäs B, Hedner T, Holmberg M, Bredenberg S, Nyström C, Lennernäs H Pharmacokinetics and tolerability of different doses of fentanyl following sublingual administration of a rapidly dissolving tablet to cancer patients: a new approach to treatment of incident pain. British Journal of Clinical Pharmacology 2005 Feb;59(2):249-53