Brand Names: Gralise, Horizant, Neurontin

Generic Name: gabapentin (Pronunciation: GA ba PEN tin)

• What is gabapentin (Horizant)?
• What are the possible side effects of gabapentin (Horizant)?
• What is the most important information I should know about gabapentin (Horizant)?
• What should I discuss with my healthcare provider before taking gabapentin (Horizant)?
• How should I take gabapentin (Horizant)?
• What happens if I miss a dose (Horizant)?
• What happens if I overdose (Horizant)?
• What should I avoid while taking gabapentin (Horizant)?
• What other drugs will affect gabapentin (Horizant)?
• Where can I get more information?

What is gabapentin (Horizant)?

Gabapentin is an anti-epileptic medication, also called an anticonvulsant. It affects chemicals and nerves in the body that are involved in the cause of seizures and some types of pain.

Gabapentin is used alone or in combination with other medications to treat seizures caused by epilepsy in adults and children who are at least 12 years old. Gabapentin is also used with other medications to treat partial seizures in children who are 3 to 12 years old.

Gabapentin is also used in adults to treat nerve pain caused by herpes virus or shingles (herpes zoster), and to treat restless legs syndrome (RLS).

Gabapentin may also be used for purposes not listed in this medication guide.

Gabapentin 100 mg Cap-IVA

white, imprinted with Logo 4381, 100 mg

Gabapentin 100 mg-APO

white, imprinted with APO, 112

Gabapentin 100 mg-GRE

white, imprinted with G, 5026

Gabapentin 100 mg-TEV

gray, imprinted with 93 38

Gabapentin 300 mg Cap-IVA

white/yellow, imprinted with Logo 4382, 300 mg

Gabapentin 300 mg-APO

white/yellow, imprinted with APO, 113

Gabapentin 300 mg-GRE

yellow, imprinted with G, 5027

Gabapentin 300 mg-TEV

orange, imprinted with 93 39

Gabapentin 400 mg Cap-IVA

orange/white, imprinted with Logo 4383, 400 mg

Gabapentin 400 mg-APO

orange/white, imprinted with APO, 114

Gabapentin 400 mg-GRE

orange, imprinted with G, 5028

Gabapentin 400 mg-TEV

brown, imprinted with 93 40

Gabapentin 600 mg Tab-IVA

oval, white, imprinted with Logo 4443, 600

Gabapentin 600 mg-APO

oblong, white, imprinted with APO, GAB 600

Gabapentin 600 mg-GRE

elliptical, white, imprinted with G 21

Gabapentin 800 mg Tab-IVA

oval, white, imprinted with Logo 4444, 800

Gabapentin 800 mg-APO

oblong, white, imprinted with APO, GAB 800

Gabapentin 800 mg-GRE

elliptical, white, imprinted with G 22

Neurontin 100 mg

white, imprinted with Neurontin 100 mg, PD

Neurontin 300 mg

yellow, imprinted with Neurontin 300 mg, PD

Neurontin 400 mg

orange, imprinted with Neurontin 400 mg, PD

Neurontin 600 mg

oval, white, imprinted with NEURONTIN 600

Neurontin 800 mg

oval, white, imprinted with NEURONTIN 800

What are the possible side effects of gabapentin (Horizant)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; fever; swollen glands; painful sores in or around your eyes or mouth; difficulty breathing; swelling of your face, lips, tongue, or throat.

Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, depression, or if you feel agitated, hostile, restless, hyperactive (mentally or physically), or have thoughts about suicide or hurting yourself.

Call your doctor at once if you have a serious side effect such as:

• increased seizures;
• fever, swollen glands, body aches, flu symptoms;
• skin rash, easy bruising or bleeding, severe tingling, numbness, pain, muscle weakness;
• upper stomach pain, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes);
• chest pain, irregular heart rhythm, feeling short of breath;
• confusion, nausea and vomiting, swelling, rapid weight gain, urinating less than usual or not at all;
• new or worsening cough, fever, trouble breathing; or
• rapid back and forth movement of your eyes.

Some side effects are more likely in children taking gabapentin. Contact your doctor if the child taking this medication has any of the following side effects:

• changes in behavior;
• memory problems;
• trouble concentrating; or
• acting restless, hostile, or aggressive.

Less serious side effects may include:

• dizziness, drowsiness, weakness, tired feeling;
• nausea, diarrhea, constipation;
• blurred vision;
• headache;
• breast swelling;
• dry mouth; or
• loss of balance or coordination.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the Horizant (gabapentin enacarbil extended-release tablets) Side Effects Center for a complete guide to possible side effects »

What is the most important information I should know about gabapentin (Horizant)?

You should not use this medication if you are allergic to gabapentin.

Before taking gabapentin, tell your doctor if you have kidney, liver, or heart disease.

You may have thoughts about suicide while taking gabapentin. Your doctor will need to check you at regular visits. Do not miss any scheduled appointments.

Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, depression, or if you feel agitated, hostile, restless, hyperactive (mentally or physically), or have thoughts about suicide or hurting yourself.

Do not stop taking gabapentin for seizures without first talking to your doctor, even if you feel fine. You may have increased seizures if you stop using gabapentin suddenly. You may need to use less and less before you stop the medication completely.

Contact your doctor if your seizures get worse or you have them more often while taking gabapentin.

Wear a medical alert tag or carry an ID card stating that you take gabapentin. Any doctor, dentist, or emergency medical care provider who treats you should know that you take seizure medication.