Gabapentin enacarbil

Gabapentin enacarbil (Horizant (ER) (U.S.Tooltip United States), Regnite (in Japan)) is an anticonvulsant and analgesic drug of the gabapentinoid class, and a prodrug to gabapentin.^[1] It was designed for increased oral bioavailability over gabapentin,^[2][3] and human trials showed it to produce extended release of gabapentin with almost twice the overall bioavailability,^[4] especially when taken with a fatty meal.^[5] Gabapentin enacarbil has passed human clinical trials for the treatment of restless legs syndrome, and initial results have shown it to be well tolerated and reasonably effective.^[6][7][8]

Gabapentin enacarbil

Clinical data
Trade names	Horizant, Regnite
Other names	XP-13512
AHFS/Drugs.com	Professional Drug Facts
License data	US DailyMed: Gabapentin_enacarbil US FDA: Horizant
Pregnancy category	AU: B1
Routes of administration	By mouth
Drug class	Gabapentinoid
ATC code	None
Legal status
Legal status	US: ℞-only
Pharmacokinetic data
Excretion	Kidney
Identifiers
IUPAC name (1-{[({(1RS)-1-[isobutyryloxy]ethoxy}carbonyl) amino]methyl}cyclohexyl)acetic acid
CAS Number	478296-72-9 Y
PubChem CID	9883933
IUPHAR/BPS	7560
ChemSpider	8059607 N
UNII	75OCL1SPBQ
ChEBI	CHEBI:68840 N
CompTox Dashboard (EPA)	DTXSID30870359
Chemical and physical data
Formula	C16H27NO6
Molar mass	329.393 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC(C)C(=O)OC(C)OC(=O)NCC1(CCCCC1)CC(=O)O
InChI InChI=1S/C16H27NO6/c1-11(2)14(20)22-12(3)23-15(21)17-10-16(9-13(18)19)7-5-4-6-8-16/h11-12H,4-10H2,1-3H3,(H,17,21)(H,18,19) N Key:TZDUHAJSIBHXDL-UHFFFAOYSA-N N
NY (what is this?)  (verify)

Gabapentin enacarbil was denied approval by the U.S. Food and Drug Administration (FDA) in February 2010, citing concerns about possible increased cancer risk shown by some animal studies. Similar concerns had been raised about gabapentin itself in the past, but were felt to be outweighed by its clinical utility as an anticonvulsant, whereas the treatment of restless legs syndrome was not seen to justify the same kind of risk.^[9] On April 6, 2011, Xenoport received FDA approval for Horizant (gabapentin enacarbil) for the treatment of moderate-to-severe restless legs syndrome.^[10] On June 7, 2012, the FDA approved Horizant for the treatment of postherpetic neuralgia in adults.^[11]