Gabapentin is an anticonvulsant used in the prevention of partial seizures. It is frequently used for neuropathic pain including diabetic neuropathy, radiculopathy, shingles, and trigeminal neuralgia.
Generic names: Gabapentin/Gabapentin Enacarbil
Brand names: Gralise, Neurontin, Horizant
Pharmacologic class: 1-amino-methyl cyclohexoneacetic acid
Therapeutic class: Anticonvulsant
Mechanism of action: Gabapentin helps to stabilize cell membranes by changing cation (sodium, calcium, and potassium) transport, reducing excitability, and suppressing seizure focus or discharge.
Indications for use: Adjunctive treatment for seizure control, postherpetic neuralgia, moderate to severe primary restless legs syndrome. Off-label uses include bipolar disorder, migraine prophylaxis, tremor associated with multiple sclerosis, neuropathic pain, diabetic peripheral neuropathy, vasomotor symptoms (hot flashes), fibromyalgia, and adjunct treatment of postoperative pain.
Precautions and contraindications:
- Take caution with severe renal impairment
- Avoid use in patients on hemodialysis
- Take caution in elderly patients, those with a history of suicidal thoughts or behavior, pregnant or breastfeeding patients, and children younger than 18 years old
Drug Interactions
- Gabapentin taken with antacids can decrease gabapentin absorption
- Antihistamines, CNS depressants, sedative-hypnotics, opiates, and alcohol can increase the risk of CNS depression
- Gabapentin coupled with hydrocodone reduces hydrocodone blood concentration while increasing gabapentin blood concentration
- Gabapentin concentration increases if taken with morphine
- Gabapentin may cause false-positive results on urinary protein dipstick tests
- White blood cells can be decreased by gabapentin
Adverse Effects
- Headache, drowsiness, dizziness, vertigo
- Confusion, hostility, anxiety, emotional lability, suicidal thoughts or behavior
- Weakness, altered reflexes, tingling and numbness (paresthesia)
- Hypertension, peripheral edema
- Abnormal vision, nasal congestion (rhinitis), sore throat (pharyngitis)
- Nausea, vomiting, constipation, indigestion (dyspepsia), dry mouth
- Erectile dysfunction
- Decreased white blood cell (leukopenia)
- Joint, back, or muscle pain; fractures
- Cough
- Itchy skin (pruritus)
- Dental abnormalities, gingivitis, facial edema, increased appetite, weight gain, multi-organ hypersensitivity
Administration Considerations
Available preparations: Capsules, oral solution, tablets, extended-release tablets (Horizant)
Dosages for adults: For treatment of partial seizures: 900-1800 mg/day. For postherpetic neuralgia: 300-1800 mg/day. For moderate to severe primary restless legs syndrome (Horizant): 600 mg PO in the evening.
Dosages for children 12 years old and older: For treatment of partial seizures: 900-1800 mg/day.
Dosages for children 5-12 years old: Dosage is dependent on weight. For treatment of partial seizures: 10-35 mg/kg/day
Dosages for children 3-4 years old: Dosage is dependent on weight. For treatment of partial seizures: 10-40 mg/kg/day
Route | Onset | Peak | Duration |
PO (capsules, oral solution, suspension) | Rapid | 2-4 hours | 8 hours |
PO tablets (Gralise) | Unknown | 8 hours | Unknown |
PO (extended-release) (Horizant) | Unknown | Unknown | Unknown |
Nursing Considerations for Gabapentin
Related Nursing Diagnoses
- Acute pain
- Risk for injury
- Risk for infection (related to decreased white blood count)
- Risk for suicide, impaired oral mucous membrane, constipation as potential side effects of gabapentin
Nursing Assessment
- Assess for allergies to gabapentin
- Monitor for changes in neurological status, changes in mood, or thoughts of suicide
- Review the patient’s history of seizures
- Assess pain scale and characteristics
- Monitor for signs of infection
- Review WBC count
- Monitor for renal impairment
Nursing Interventions
- Administer with or without food. May give with food to reduce gastrointestinal upset.
- Do not exceed the maximum interval of 12 hours in between doses when administered 3 times per day. To discontinue gabapentin or start an anticonvulsant, titrate gradually for at least one week to reduce the risk of seizure.
- Implement seizure precautions.
- Implement strict hand hygiene and infection control.
- Report observations of depression, suicidal thoughts, or unusual behavior.
- Inform the provider of signs of allergic reactions (difficulty of breathing, coughing, or swelling of face or tongue).
Patient Teaching Associated with Gabapentin
- Advise the patient that gabapentin can be taken with or without food.
- Instruct to swallow extended-release tablets without breaking, crushing, dissolving, or chewing.
- Inform to take gabapentin at bedtime to minimize adverse effects.
- Do not suddenly stop gabapentin due to the increased risk of seizure.
- Teach the patient to avoid driving and activities that require concentration until the effects have been evaluated.
- Inform the patient this drug may cause joint, muscle, or bone pain.
- Immediately report signs of depression, suicidal thoughts, or unusual behavior.
- Advise avoiding alcohol intake.
- Recommend to always carry identification noting seizure disorder/anticonvulsant therapy.
- Immediately report signs of hypersensitivity including fever or enlarged lymph nodes.
This is not an all-inclusive list of possible drug interactions, adverse effects, precautions, nursing considerations, or patient instructions. Please consult further with a pharmacist for complete information.
References and Sources
- Kizior, R. J., & Hodgson, K. J. (2019). Saunders Nursing Drug Handbook 2019. Elsevier Health Sciences.
- Schull, P. (2013). McGraw-hill nurses drug handbook (7th ed.). McGraw Hill Professional.