Riluzole is used to treat amyotrophic lateral sclerosis (ALS; Lou Gehrig’s disease). Riluzole is in a class of medications called benzothiazoles. It works by changing the activity of certain natural substances in the body that affect nerves and muscles.

Side Effects Of Riluzole

Riluzole may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • weakness
  • dizziness
  • dry mouth
  • mouth numbness
  • difficulty falling asleep or staying asleep
  • drowsiness
  • swelling of the hands, feet, ankles, or lower legs
  • fast heart rate

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

  • hives
  • rash
  • itching
  • difficulty breathing or swallowing
  • dry cough
  • nausea
  • stomach pain
  • vomiting
  • extreme tiredness
  • unusual bleeding or bruising
  • loss of appetite
  • pain in the upper right part of the stomach
  • yellowing of the skin or eyes
  • dark urine
  • fever, chills, cough, or other signs of infection
  • muscle or joint pain
  • headache

Warnings & Precautions

Before taking riluzole:

  • tell your doctor and pharmacist if you are allergic to riluzole, any other medications, or any of the ingredients in riluzole tablets or suspension. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: allopurinol (Aloprim, Lopurin, Zyloprim), carbamazepine (Carbatrol, Epitol, Equetro, Tegretol), ciprofloxacin (Cipro), fluvoxamine (Luvox), methoxsalen (8-MOP, Oxsoralen), methyldopa (in Aldochlor), mexiletine, oral contraceptives (birth control pills), rifampin (Rifadin, in Rifamate, in Rifater), sulfasalazine (Azulfidine), vemurafenib (Zelboraf), and zileuton (Zyflo).
  • tell your doctor if you are of Japanese descent and if you have or have ever had kidney or liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking riluzole, call your doctor.
  • tell your doctor if you use tobacco products. Cigarette smoking may decrease the effectiveness of this drug.

Dosage Of Riluzole

Riluzole comes as a tablet and a suspension (liquid) to take by mouth. It usually is taken on an empty stomach (1 hour before or 2 hours after meals) twice a day, every 12 hours. You should take it at the same times each day (usually in the morning and in the evening). Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take riluzole exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Shake the suspension well (at least 30 seconds) before each use to mix the medication evenly. Be sure to turn the bottle up and down until you do not see the clear liquid at the top or any particles at the bottom of the bottle. Read the instructions for use before you start taking riluzole suspension. Be sure that you understand these directions, and ask your pharmacist if you have any questions.

Riluzole may slow the progression of ALS but does not cure it. Continue to take riluzole even if you feel well. Do not stop taking riluzole without talking to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.


Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body’s response to riluzole.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.