Product Information

Registration Status: Active

FENTORA® BUCCAL TABLETS 800 MCG is approved to be sold in Singapore with effective from 2020-07-28. It is marketed by TEVA PHARMACEUTICAL INVESTMENTS SINGAPORE PTE LTD, with the registration number of SIN15977P.

This product contains Fentanyl 800 mcg in the form of TABLET, EFFERVESCENT. It is approved for BUCCAL use.

This product is manufactured by Anesta LLC in UNITED STATES.

It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.



A potent narcotic analgesic, abuse of which leads to habituation or addiction. It is primarily a mu-opioid agonist. Fentanyl is also used as an adjunct to general anesthetics, and as an anesthetic for induction and maintenance. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1078)


For the treatment of cancer patients with severe pain that breaks through their regular narcotic therapy.

Mechanism of Action

Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine and noradrenaline is inhibited. Opioids also inhibit the release of vasopressin, somatostatin, insulin and glucagon. Fentanyl's analgesic activity is, most likely, due to its conversion to morphine. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hypopolarization and reduced neuronal excitability.


Bioavailability is 92% following transdermal administration and 50% following buccal administration.
* 3 to 8 L/kg [Surgical Patients] * 0.8 to 8 [Hepatically Impaired Patients]
Fentanyl is metabolized primarily via human cytochrome P450 3A4 isoenzyme system.


* 27 – 75 L/h [Surgical Patients receving IV administration] * 3 – 80 L/h [Hepatically Impaired Patients receving IV administration] * 30 – 78 L/h [Renally Impaired Patients receving IV administration]


Fentanyl has an LD50 of 3.1 milligrams per kilogram in rats, and, 0.03 milligrams per kilogram in monkeys. The LD50 in humans is not known.

Active Ingredient/Synonyms

1-Phenethyl-4-(N-phenylpropionamido)piperidine | 1-phenethyl-4-N-propionylanilinopiperidine | Fentanil | Fentanila | Fentanilo | Fentanyl | Fentanyl CII | Fentanylum | N-(1-phenethyl-4-piperidinyl)-N-phenylpropionamide | N-(1-phenethyl-4-piperidyl)propionanilide | N-(1-Phenethyl-piperidin-4-yl)-N-phenyl-propionamide | N-(1-phenethylpiperidin-4-yl)-N-phenylpropionamide | N-phenethyl-4-(N-propionylanilino)piperidine | N-phenyl-N-(1-(2-phenylethyl)-4-piperidinyl)propanamide | Phentanyl | Fentanyl |

Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


  1. Health Science Authority of Singapore - Reclassified POM
  2. Drugbank