PROFILPELAJAR.COM

Alfentanil
Clinical data
Trade names	Alfenta, Rapifen, others
AHFS/Drugs.com	Micromedex Detailed Consumer Information
MedlinePlus	a601130
Routes of; administration	Intravenous, subcutaneous
Drug class	Opioid
ATC code	N01AH02 (WHO) ;
Legal status
Legal status	AU: S8 (Controlled drug); BR: Class A1 (Narcotic drugs); CA: Schedule I; DE: Anlage III (Special prescription form required); UK: Class A; US: Schedule II;
Pharmacokinetic data
Bioavailability	~50%
Protein binding	92%
Metabolism	Hepatic
Elimination half-life	90–111 minutes
Duration of action	15 minutes
Identifiers
	IUPAC name N-{1-[2-(4-ethyl-5-oxo-4,5-dihydro-1H-1,2,3,4-tetrazol-1-yl)ethyl]-4-(methoxymethyl)piperidin-4-yl}-N-phenylpropanamide;
CAS Number	71195-58-9 ;
PubChem CID	51263;
IUPHAR/BPS	7108;
DrugBank	DB00802 ;
ChemSpider	46451 ;
UNII	1N74HM2BS7;
KEGG	D07122 ;
ChEBI	CHEBI:2569 ;
ChEMBL	ChEMBL634 ;
CompTox Dashboard (EPA)	DTXSID9022570 ;
ECHA InfoCard	100.295.336
Chemical and physical data
Formula	C21H32N6O3
Molar mass	416.526 g·mol−1
3D model (JSmol)	Interactive image;
Melting point	140.8 °C (285.4 °F)
	SMILES O=C1N(\N=N/N1CC)CCN3CCC(N(c2ccccc2)C(=O)CC)(CC3)COC;
	InChI InChI=1S/C21H32N6O3/c1-4-19(28)27(18-9-7-6-8-10-18)21(17-30-3)11-13-24(14-12-21)15-16-26-20(29)25(5-2)22-23-26/h6-10H,4-5,11-17H2,1-3H3 ; Key:IDBPHNDTYPBSNI-UHFFFAOYSA-N ;
	(verify)

Alfentanil (R-39209), sold under the brand name Alfenta among others, is a potent but short-acting synthetic opioid analgesic drug used for anesthesia in surgery. It is an analogue of fentanyl with around one-fourth to one-tenth the potency, one-third the duration of action, and an onset of action four times faster than that of fentanyl.^[3] Alfentanil has a pKa of approximately 6.5, which leads to a very high proportion of the drug being uncharged at physiologic pH, a characteristic responsible for its rapid-onset. It is an agonist of the μ-opioid receptor.

While alfentanil tends to cause fewer cardiovascular complications than other similar drugs such as fentanyl and remifentanil, it tends to give stronger respiratory depression and so requires careful monitoring of breathing and vital signs. Almost exclusively used by anesthesia providers during portions of a case where quick, fast-acting (though not long-lasting) pain control is needed (as, for example, during nerve blocks), alfentanil is administered by the parenteral (injected) route for fast-onset and precise control of dosage.

Discovered at Janssen Pharmaceutica in 1976, alfentanil is classified as a Schedule II drug in the United States.^[4]

Side effects of fentanyl analogs are similar to those of fentanyl itself and include itching, nausea and potentially life-threatening respiratory depression. Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear.^[5]