riluzole

Action and Spectrum

Actions and Spectrum:  

Action: 

Inhibition of Glutamate Release: Riluzole has been found to act on the mechanism that can help reduce the nerve cell stimulation since excessive stimulation of nerve cells by glutamate leads to nerve cell degeneration in ALS.
Inhibition of Voltage-Gated Sodium Channels: Riluzole interacts with some of the sodium channels; thus, it can decrease neuronal sensitivity and limit the glutamate leakage. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

Nausea (16%) 

Asthenia (19%) 

Oral hypoesthesia (29%) 

1-10% 

Flatulence (3%) 

Tachycardia (3%) 

Pruritus (4%) 

Insomnia (4%) 

Dry mouth (4%) 

Dizziness (4%) 

Arthralgia (4%) 

Vomiting (4%) 

Abdominal pain (5%) 

Hypertension (5%) 

Decreased lung function (10%) 

Post marketing Reports 

Pancreatitis 

Renal tubular impairment 

Icteric toxic hepatitis 

Acute hepatitis 

Black Box Warning

Blackbox warning: 

None  

Contraindication / Caution

Contraindications/Cautions: 

Contraindications: 

Hypersensitivity  

Cautions: 

Hepatic injury 

Interstitial lung disease 

Drug interactions 

Pregnancy / Lactation

Pregnancy/Lactation: 

Pregnancy consideration:  

Pregnancy category: Not assigned  

Lactation: Excreted into human milk is unknown  

Pregnancy category:  

• Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.  
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.  
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.   
• Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.  
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.  
• Category N: There is no data available for the drug under this category.  

Pharmacology

Pharmacology: Riluzole is used in the treatment of ALS. 

Pharmacodynamics: 

Inhibition of Glutamate Release: Riluzole prevents the release of the excitatory neurotransmitter glutamate at synaptic level which may be neurotoxic when it is in high concentration.
Inactivation of Voltage-Dependent Sodium Channels: It prevent the sustained opening of sodium channels which is believed to play a crucial role in the stabilization of neuronal membrane. 

Pharmacokinetics: 

Absorption 

Riluzole is rapidly and well absorbed from the gastrointestinal tract after oral administration with time to the maximum concentration ranging from 1 to 1. 5 hours. The bioavailability of riluzole is approximatley 60%.
Distribution 

It is distributed throughout the body. 

Metabolism 

Riluzole undergoes mainly hepatic metabolism, and the major metabolic pathway involves the cytochrome P450 enzymes CYP1A2.
Excretion and Elimination 

The major amount of the drug and its metabolites are excreted through urine. The half-life of riluzole is approximately 12 hours. 

Adminstartion

Administration: 

The drug is taken orally. 

Patient Information Leaflet

Patient information leaflet 

Generic name: riluzole 

Why do we use riluzole? 

Riluzole is likely to slow the progression of ALS which at one time increase the chance of survival and or time before mechanical ventilation.
Riluzole works through the blockade of the release of glutamate, a neurotransmitter which, in excessive amounts, is toxic to neurons. This neuroprotective effect eventually entails a longer preservation of the motor neurons.