Riluzole

What you should know

Riluzole:

• is a glutamate-blocking medication
• does not cure motor neurone disease (MND) but may slow disease progression
• may extend average survival by 6 to 19 months
• is best taken as soon as possible after diagnosis 
• has only been studied for its safety and efficacy in specific forms of MND including ALS (the most common form of MND) and progressive bulbar palsy (PBP).

Riluzole and MND

Motor neurone disease is a general term applying to progressive, degenerative disorders affecting the motor neurones. Motor neurones carry signals from the brain to the muscles. In people with motor neurone disease, the motor neurones deteriorate and can no longer carry these signals.

Glutamate is a neurotransmitter (a chemical that can carry a signal from one cell to another) that is released at the synaptic junction where two neurones meet. It stimulates and excites motor neurone cells, causing them to fire and send their signals.¹ If too much glutamate is released by the neurone sending a signal, it can over-stimulate the neurone receiving the signal. This is called glutamate excitotoxicity. It has been suggested that over-stimulation (excitotoxicity) of neurones due to excessive glutamate signalling activity may contribute to motor neurone deterioration and thereby, MND.^1,2

Riluzole is a medication which appears to reduce the release of glutamate from neurones, thereby protecting motor neurone cells from excitotoxicity and thus deterioration.^1,3 Riluzole may also exert some effects on MND through other mechanisms but this has yet to be firmly established.

The effect of riluzole has been investigated on people with the following forms of motor neurone disease:

• amyotrophic lateral sclerosis (ALS) – muscles controlling the limbs are the first affected;
• progressive bulbar palsy (PBP) – bulbar muscles (speech and swallowing muscles) are the first affected but often progresses to ALS.

Medical literature about riluzole generally uses the term amyotrophic lateral sclerosis (ALS) as an umbrella term to include progressive bulbar palsy (PBP).

This is because there is:

• uncertainty about the cause and mechanism of motor neurone deterioration;
• debate about the extent to which different forms are simply variations in the same disease process or whether there are several different disease mechanisms;
• international difference in terms used to describe motor neurone disease.

Getting riluzole

Riluzole is manufactured under the names Rilutek™ and APO-Riluzole. In Australia, riluzole is available for eligible people at a subsidised price on the Pharmaceutical Benefits Scheme (PBS) under an authority prescription.⁴ To get your first authority prescription for riluzole you must be diagnosed with the ALS form (including PBP) of MND by a neurologist, have had the disease for five years or less and meet several other criteria. Your doctor needs to provide your date of diagnosis and information about your forced vital capacity* with the first application. Subsequent prescriptions may be issued by your general practitioner.

Teglutik® (riluzole) is a liquid formulation⁵ (for ease of swallowing or use via PEG tube) of riluzole distributed by Seqirus (Australia) Pty Ltd. It was listed on the PBS in April 2019 under the same prescribing conditions as Rilutek™ and APO-Riluzole.

*Forced vital capacity is a test of respiratory function recommended for assessing and monitoring breathing for people with MND¹ – it is the volume of air you can forcibly exhale after a full inhalation. You can read more about respiratory tests for people with MND in the Breathing and MND: an introduction factsheet.

Evidence about riluzole

For people with MND who have ALS (including PBP), a benchmark systematic review was published in 2012 which found that taking 100 mg of riluzole daily improved average survival time by two to three months.²

More recent research suggests that riluzole may be more effective than first thought.⁶ A review of 15 population studies undertaken by clinicians treating people with ALS/MND found that people who took riluzole compared with those who didn’t, generally lived 6 to 19 months longer.⁶

This review provides additional insights into the effectiveness of riluzole as an important treatment option for people living with ALS. Additionally, the review found that the greatest benefit of riluzole occurs early in the course of disease, providing evidence to support early and prolonged riluzole therapy.⁶

For people with other forms of MND

While the current literature investigating the use of Riluzole is focused on people with the ALS form (including PBP) of motor neurone disease, there is strong clinical support for the use of riluzole in other forms of motor neurone disease.¹

In Australia, subsidised PBS prescriptions for riluzole are limited as a treatment for the ALS (including PBP) forms of motor neurone disease alone.⁴

Adverse effects

Adverse effects from riluzole are relatively minor and, for the most part, reversible after stopping the drug.¹ The most common adverse effects are fatigue and nausea. Riluzole affects liver function and should be prescribed with care in people who have pre-existing problems with liver function.¹

Ongoing liver function testing

Regular blood testing to monitor liver function (every month for three months, then every three months for a further nine months and annually thereafter) is recommended for people taking riluzole.¹

Getting advice about riluzole

Your neurologist can offer advice about riluzole. If you have been refused access to riluzole under the PBS and think you are eligible, talk with a neurologist or contact your MND clinic or state association.