Riluzole is a benzothiazole derivative and the first disease-modifying agent approved for the treatment of Amyotrophic Lateral Sclerosis (ALS). It is a neuroprotective agent that modulates glutamatergic neurotransmission. In the Indian context, it is a critical but high-cost therapy for a debilitating neurological condition, often requiring patient assistance programs for access.
Adult: 50 mg every 12 hours (on an empty stomach, at least 1 hour before or 2 hours after meals).
Note: Take tablet whole with a glass of water. Must be taken at least 1 hour before or 2 hours after meals to ensure consistent absorption. Maintain a consistent dosing schedule.
Riluzole's primary mechanism is the inhibition of glutamate release from pre-synaptic terminals. It also inactivates voltage-dependent sodium channels on neurons, preventing sustained neuronal firing. Furthermore, it non-competitively blocks NMDA and kainate subtypes of glutamate receptors. This multi-pronged approach reduces excitotoxic neuronal damage, a key pathological process in ALS.
Pregnancy: Category C (US FDA). Animal studies show teratogenicity. Use only if potential benefit justifies potential fetal risk. Not recommended during pregnancy.
Driving: May cause dizziness, vertigo, and somnolence. Patients should be cautioned about operating machinery or driving until they know how the drug affects them.
| Ciprofloxacin | Potent CYP1A2 inhibitor; increases riluzole plasma levels by up to 120%. Risk of toxicity. | Major |
| Aminophylline/Theophylline | CYP1A2 substrate; riluzole may increase theophylline levels. Monitor for toxicity. | Moderate |
| Omeprazole | CYP1A2 inducer; may decrease riluzole plasma levels, reducing efficacy. | Moderate |
| Rifampicin | Potent enzyme inducer; significantly decreases riluzole exposure. Avoid combination. | Major |
| Charcoal | Reduces absorption of riluzole if taken concomitantly. | Moderate |
| High-dose Paracetamol (Acetaminophen) | Potential additive risk of hepatotoxicity. Monitor LFTs closely. | Moderate |
| Other Hepatotoxic drugs (e.g., Statins, NSAIDs) | Increased risk of liver injury. Requires enhanced monitoring. | Moderate |