Description

Simple

A medication used to treat Restless Legs Syndrome (RLS) and to treat pain associated with the shingles virus that persists even once the rash associated with the virus has healed (postherpetic neuralgia).

Clinical

A gabapentin prodrug used to treat Restless Legs Syndrome (RLS) and postherpetic neuralgia (PHN).

Overview

Gabapentin enacarbil is marketed under the name Horizant. It is a prodrug of gabapentin, and indicated in adults for the treatment of Restless Legs Syndrome (RLS) and postherpetic neuralgia (PHN).

Pharmacology

Indication

For the treatment of adult Restless Legs Syndrome (RLS) and postherpetic neuralgia (PHN).

Pharmacodynamic

Since gabapentin enacarbil is a prodrug of gabapentin, it's physiological effects are the same as gabapentin. Concerning PHN, gabapentin prevents allodynia and hyperalgesia.

Mechanism of action

Although the exact mechanism of action of gabapentin in RLS and PHN is unknown, it is presumed to involve the descending noradrenergic system, resulting in the activation of spinal alpha2-adrenergic receptors.

Absorption

Gabapentin enacarbil is absorbed in the intestines by active transport through the proton-linked monocarboxylate transporter, MCT-1.

Protein binding

Gabapentin plasma protein binding is less than 3%.

Volume of distribution

The volume of distribution is 76L.

Clearance

Renal clearance of gabapentin is 5 to 7 L/hr.

Half life

The elimination half-life of gabapentin is 5.1 to 6.0 hours.

Route of elimination

Gabapentin enacarbil is eliminated primarily in the urine (94%) and to a lesser extent in the feces (5%).

Toxicity

Most common adverse reactions are headache, dizziness, and somnolence.

Adverse Effects

Contraindications

  • Hypersensitivity:
    • false
  • Regions: US

Food Interactions

  • Take with or without food.

Interactions

Type in a drug name to check for interaction with Gabapentin enacarbil
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  • Paracetamol(acetaminophen)
  • Paxil(paroxetine)
  • Pamelor(nortriptyline)
  • Panadol(acetaminophen)
  • Patanol(olopatadine ophthalmic)
  • Pataday(olopatadine ophthalmic)
  • Parnate(tranylcypromine)
  • Pazeo(olopatadine ophthalmic)
2,5-Dimethoxy-4-ethylthioamphetamine
The risk or severity of adverse effects can be increased when Gabapentin enacarbil is combined with 2,5-Dimethoxy-4-ethylthioamphetamine.
4-Bromo-2,5-dimethoxyamphetamine
The risk or severity of adverse effects can be increased when 4-Bromo-2,5-dimethoxyamphetamine is combined with Gabapentin enacarbil.
4-Methoxyamphetamine
The risk or severity of adverse effects can be increased when 4-Methoxyamphetamine is combined with Gabapentin enacarbil.
5-methoxy-N,N-dimethyltryptamine
The risk or severity of adverse effects can be increased when Gabapentin enacarbil is combined with 5-methoxy-N,N-dimethyltryptamine.
7-Nitroindazole
The risk or severity of adverse effects can be increased when 7-Nitroindazole is combined with Gabapentin enacarbil.
7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline
The risk or severity of adverse effects can be increased when 7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline is combined with Gabapentin enacarbil.
Abacavir
Abacavir may decrease the excretion rate of Gabapentin enacarbil which could result in a higher serum level.
Acarbose
Acarbose may decrease the excretion rate of Gabapentin enacarbil which could result in a higher serum level.
Aceclofenac
Aceclofenac may decrease the excretion rate of Gabapentin enacarbil which could result in a higher serum level.
Acemetacin
Acemetacin may decrease the excretion rate of Gabapentin enacarbil which could result in a higher serum level.
Acepromazine
The risk or severity of adverse effects can be increased when Acepromazine is combined with Gabapentin enacarbil.
Aceprometazine
The risk or severity of adverse effects can be increased when Aceprometazine is combined with Gabapentin enacarbil.
Acetaminophen
Acetaminophen may decrease the excretion rate of Gabapentin enacarbil which could result in a higher serum level.
Acetazolamide
The risk or severity of adverse effects can be increased when Acetazolamide is combined with Gabapentin enacarbil.
Acetophenazine
The risk or severity of adverse effects can be increased when Acetophenazine is combined with Gabapentin enacarbil.
Acetylglycinamide chloral hydrate
The risk or severity of adverse effects can be increased when Gabapentin enacarbil is combined with Acetylglycinamide chloral hydrate.
Acetylsalicylic acid
Acetylsalicylic acid may decrease the excretion rate of Gabapentin enacarbil which could result in a higher serum level.
Aclidinium
Gabapentin enacarbil may increase the central nervous system depressant (CNS depressant) activities of Aclidinium.
Acrivastine
Gabapentin enacarbil may decrease the excretion rate of Acrivastine which could result in a higher serum level.
Acyclovir
Acyclovir may decrease the excretion rate of Gabapentin enacarbil which could result in a higher serum level.
3 References
  1. 1 . Cundy KC, Branch R, Chernov-Rogan T, Dias T, Estrada T, Hold K, Koller K, Liu X, Mann A, Panuwat M, Raillard SP, Upadhyay S, Wu QQ, Xiang JN, Yan H, Zerangue N, Zhou CX, Barrett RW, Gallop MA: XP13512 [(+/-)-1-([(alpha-isobutanoyloxyethoxy)carbonyl] aminomethyl)-1-cyclohexane acetic acid], a novel gabapentin prodrug: I. Design, synthesis, enzymatic conversion to gabapentin, and transport by intestinal solute transporters. J Pharmacol Exp Ther. 2004 Oct;311(1):315-23. Epub 2004 May 14.PubMed: 15146028
  2. 2 . Bialer M: New antiepileptic drugs that are second generation to existing antiepileptic drugs. Expert Opin Investig Drugs. 2006 Jun;15(6):637-47.PubMed: 16732716
  3. 3 . Cundy KC, Annamalai T, Bu L, De Vera J, Estrela J, Luo W, Shirsat P, Torneros A, Yao F, Zou J, Barrett RW, Gallop MA: XP13512 [(+/-)-1-([(alpha-isobutanoyloxyethoxy)carbonyl] aminomethyl)-1-cyclohexane acetic acid], a novel gabapentin prodrug: II. Improved oral bioavailability, dose proportionality, and colonic absorption compared with gabapentin in rats and monkeys. J Pharmacol Exp Ther. 2004 Oct;311(1):324-33. Epub 2004 May 14.PubMed: 15146029