Riluzole: Neuroprotective Treatment for ALS
Riluzole is a neuroprotective agent and the primary medication proven to be effective in slowing the progression of Amyotrophic Lateral Sclerosis (ALS), also known as Charcot's disease or Lou Gehrig's disease. The drug is a benzothiazole derivative and possesses a complex, multifactorial mechanism of action on the central nervous system.
The main therapeutic concept of riluzole is based on the "glutamate excitotoxicity" hypothesis. Glutamate is the primary excitatory neurotransmitter in the CNS; however, its excessive accumulation in the synaptic cleft leads to neuronal overstimulation and subsequent death. Riluzole blocks the release of glutamate from presynaptic terminals, inactivates voltage-dependent sodium channels, and interferes with intracellular signaling protein cascades. Thus, the drug protects motor neurons from degeneration, helping to maintain functional muscle activity for a longer period.
Clinical studies have confirmed that regular intake of riluzole significantly increases patient survival and delays the need for a tracheostomy or the initiation of mechanical ventilation.
Indications
Riluzole has a highly specialized application and is used strictly as prescribed by a neurologist:
- Amyotrophic Lateral Sclerosis (ALS): The drug is indicated to extend life or delay the time to mechanical ventilation for patients with ALS.
- Therapy is most effective when started early; however, the drug is prescribed at any stage of confirmed ALS to slow down the degenerative processes in motor neurons.
- Note: Riluzole is not a cure for ALS and does not restore already lost motor functions, but it significantly impacts the disease prognosis.
Dosage and administration
The riluzole treatment regimen is standardized but requires regular monitoring of blood biochemical parameters.
- Recommended Dosage: 100 mg per day, divided into two doses of 50 mg (one tablet in the morning and one in the evening).
- Administration Rules: The drug should be taken strictly on an empty stomach — 1 hour before or 2 hours after a meal. This is because high-fat food significantly reduces the bioavailability and plasma concentration of riluzole.
- Duration of Therapy: Treatment is long-term and continues as long as it remains therapeutically appropriate.
- Essential Monitoring: During the first 3 months of intake, liver transaminase levels (ALT, AST) must be checked monthly. During the first year, monitoring is performed quarterly, and thereafter as directed by a physician. If ALT levels rise to more than 5 times the upper limit of normal, the drug must be discontinued.
- Missed Dose: If a tablet is missed, the next one should be taken at the usual time. Taking a double dose is strictly prohibited.
The use of riluzole is contraindicated in the following conditions:
- Liver Disease: Presence of acute liver disease or baseline elevation of liver enzymes more than 3 times the upper limit of normal before starting therapy.
- Pregnancy and Lactation: The drug is strictly contraindicated for pregnant women and during breastfeeding (safety studies have not been conducted in this group).
- Renal Impairment: Severe impairment of kidney function (clinical experience in this group is limited).
- Pediatric Use: The drug is not used in pediatric practice.
- Hypersensitivity: Individual intolerance to riluzole or any excipients contained in the tablet.
Riluzole is generally characterized by good tolerability, but the following adverse events may occur:
- General symptoms: Marked asthenia (weakness), increased fatigue, dizziness, and somnolence.
- Digestive system: Nausea (most common), vomiting, epigastric pain, and diarrhea.
- Hepatobiliary system: Increased ALT, AST, and bilirubin levels. In rare cases, toxic hepatitis may develop.
- Neurology: Headache and oral paresthesia (tingling sensation around the mouth).
- Cardiovascular system: Tachycardia and increased blood pressure.
- Hematologic system: Very rarely — neutropenia or agranulocytosis (if an unexplained fever occurs, the patient must immediately undergo a blood test).
- Respiratory system: In exceptional cases, interstitial lung disease may develop.
