Table 1: Maximum Recommended Adult Gabapentin Dosages

Treatment Indication Drug Name Dosage Form/Strength Maximum Recommended Dosage
Partial seizures with/without secondary generalized tonic-clonic seizures gabapentin (Neurontin®, generics) 100 mg, 300 mg, 400 mg immediate-release (IR) capsules 600 mg, 800 mg IR tablet 250 mg/5 mL, 300 mg/ 6 mL oral solution 2400 mg/day (in three divided doses*)
Postherpetic neuralgia-associated neuropathic pain gabapentin (Neurontin®, generics) 100 mg, 300 mg, 400 mg IR capsules 600 mg, 800 mg IR tablet 250 mg/5 mL, 300 mg/ 6 mL oral solution 3600 mg daily in divided doses+
Postherpetic neuralgia-associated neuropathic pain gabapentin (Gralise®) 300 mg, 600 mg extended-release (ER) tablets 1800 mg once daily
Postherpetic neuralgia-associated neuropathic pain gabapentin enacarbil (Horizant®) 300 mg, 600 mg ER tablet 1200 mg daily in two divided doses
Restless legs syndrome gabapentin enacarbil (Horizant®) 300 mg, 600 mg ER tablet 600 mg daily at 5 pm^

Legend:

  • *Doses of 3600 mg/day have also been well tolerated in small numbers of patients for abbreviated treatment durations.
  • +Doses up to 3600 mg/day have been administered with therapeutic effect; however, additional benefit with doses greater than 1800 mg/day may not be observed.
  • ^Gabapentin enacarbil doses up to 1200 mg daily have been used in clinical trials with no additional benefit and increased adverse reactions.