Rilutek (Riluzole) for ALS

Last updated Dec. 1, 2022, by Teresa Carvalho, MS

✅ Fact-checked by Inês Martins, PhD


What is Rilutek for ALS?

Rilutek (riluzole) is an oral treatment that works to delay the decline in respiratory function and extend survival in people with amyotrophic lateral sclerosis (ALS).

The brand-name medication is sold in the U.S. by Covis Pharma, but several generic forms of Rilutek have been approved in the country since 2003.

Rilutek and its generics are sold as tablets, but the active ingredient in them also is available in other formulations.

How does Rilutek work?

The exact causes of ALS are not fully understood, but one of the mechanisms leading to nerve cell damage with the condition is thought to be the release of too much glutamate.

Glutamate is a neurotransmitter required for nerve cells to communicate with each other. But when released in excess, this molecule can lead nerve cells to fire too much, eventually triggering a cascade of events that culminates in nerve cell death.

When one nerve cell dies from this excess activation, it releases glutamate into its surroundings, which can contribute to the death of neighboring nerve cells in a continuous loop.

Although Rilutek’s exact mechanism of action is not completely elucidated, it’s thought to block glutamate signaling in nerve cells  reducing the rate of glutamate-induced deterioration in nerve cells and slowing the progression of symptoms.

Recent studies suggest Rilutek can reduce the toxic accumulation of TDP-43 protein clumps, which occurs in about 97% of ALS cases and is thought to contribute to nerve cell dysfunction.

Who can take Rilutek?

The U.S. Food and Drug Administration (FDA) approved Rilutek for ALS patients in 1995, making it the first medication approved in the country for the neurodegenerative disease.

The treatment is also approved in dozens of countries worldwide.

Who should not use Rilutek?

The medication is not recommended for people with a history of severe allergic reactions to riluzole or any other component in Rilutek.

How is Rilutek administered?

Rilutek is available in film-coated, capsule-shaped tablets containing 50 mg of the active medication. These capsules are white and engraved with “RPR 202” on one side.

The recommended dose is 50 mg, taken as one oral tablet twice a day. Rilutek should be taken at least two hours after the last meal and patients should not eat for at least one hour after taking the medication.

Tablets should be swallowed whole, not broken, crushed, or chewed.

Rilutek in clinical trials

Rilutek’s regulatory approvals were supported by efficacy data from two key clinical trials, both of which enrolled patients with sporadic or familial ALS whose symptoms had appeared within the last five years.

Trial 1

The first trial enrolled 155 patients and randomly assigned them to receive a 50 mg dose of Rilutek or a placebo, given as twice daily tablets for one year. The trial’s main goal was to determine whether the medication could delay the time to death or to require a tracheostomy, a procedure wherein a tube is inserted through the neck into the windpipe to help with breathing. Another main goal was to assess changes in functional status after treatment.

Rilutek significantly extended the time to death or tracheostomy by nearly three months. The median time to death or tracheostomy with the placebo group was 449 days, while the median time for the riluzole group was 532 days. The proportion of patients who died in the first 12 months was 38.6% lower with Rilutek, which was deemed clinically important and statistically significant.

The decline in muscle strength also was significantly slower in patients given Rilutek.

Trial 2

The second trial tested ascending doses of Rilutek in a total of 959 ALS patients from sites in Europe and North America. Participants were randomly assigned to 50 mg, 100 mg, or 200 mg of Rilutek, or a placebo, given daily for 18 months. Those who completed this part, were given the option to continue on the 100 mg dose of Rilutek in an open-label study.

While the time to requiring a tracheostomy or death was not significantly different between the 50 mg dose and a placebo, the 100 and 200 mg doses led to a significant delay in those events. Tracheostomy-free survival was similar for these higher doses, but the 200 mg dose resulted in an increase in certain side effects, such as dizziness, diarrhea, and anorexia.

Rilutek prolonged survival by significantly extending the time patients lived in the most advanced stage of the disease, additional analyses from the trial showed. In contrast, the treatment had no impact on the time lived in earlier disease stages.

Common side effects of Rilutek

The most common side effects associated with Rilutek include:

  • generalized weakness
  • nausea
  • dizziness
  • decreased lung function
  • abdominal pain

Liver damage

Rilutek may cause liver damage that can be life-threatening in some cases. Patients receiving this medication should be regularly monitored for signs and symptoms of liver damage and should not take Rilutek if the levels of their liver enzymes are at least five times higher than the upper limit of normal. Use of Rilutek alongside other hepatotoxic drugs may further increase the risk of liver damage.

Low levels of white blood cells

Neutropenia, in which white blood cells called neutrophils are lower than normal, may occur during the first months of treatment. As the condition is often accompanied by a fever, patients should report any increases in temperature to their healthcare team.

Lung scarring

Taking Rilutek may lead to interstitial lung disease, a condition marked by “scarring” of the lung tissue. The medication should be stopped immediately if this form of lung disease develops.

Use in pregnancy and breastfeeding

Rilutek has not been well studied during pregnancy in humans, but animal data suggests it may cause harm to a developing fetus. It’s also unknown if it can pass to breast milk in humans, although it has been detected in the milk of lactating rats.

Patients who plan to become pregnant or breastfeed should talk with their healthcare team about these issues.


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