Riluzole-induced interstitial lung disease is a rare and potentially life-threatening adverse event successfully treated with high-dose steroid therapy: Case reports and review of the literature

Treatment continuity of amyotrophic lateral sclerosis with available riluzole formulations: state of the art and current challenges in a 'real-world' setting

Amyotrophic lateral sclerosis (ALS) is a rare multisystem neurodegenerative disease leading to death due to respiratory failure. Riluzole was the first disease modifying treatment approved in ALS. Randomized clinical trials showed a significant benefit of riluzole on survival in the months following randomization, with a good safety profile. 'Real-world' studies suggested that the survival benefit of riluzole is substantially greater, with an extended survival ranging between 6 and 19 months. The main limiting associated adverse effects of riluzole are non-severe gastrointestinal complications and an elevation of liver enzymes, observed in 10% of patients. While different classes of drugs have been approved in some countries, riluzole remains the gold standard of therapy. Dysphagia induced by ALS is a major challenge for food intake and riluzole administration. Tablet crushing is associated with a loss of drug intake and a risk of powder aspiration, which jeopardizes the benefits of riluzole. Riluzole oral suspension (ROS) and oral film (ROF) allow riluzole intake in patients with dysphagia. Both formulations are bioequivalent to riluzole tablets with a good safety profile albeit transient oral hypoaesthesia. In case of severe dysphagia, ROS can be used with percutaneous endoscopic gastrostomy. ROF, the last approved formulation, requires low swallowing capacities and may contribute to maintain the efficacy of riluzole when tablets are inadequate according to patient's status and/or preferences. To optimize treatment continuity in newly diagnosed patients, the expected psychological impact of formulation switching that may be perceived as the sign of disease progression should be anticipated.

Real-world safety profile of riluzole: a systematic analysis of data from the FAERS database and case reports

BACKGROUND

The study aims to obtain the safety profile of riluzole in the real world and provide reference for clinical drug applications.

RESEARCH DESIGN AND METHODS

Proportional reporting ratio (PRR) was used to detect riluzole adverse drug reactions (ADRs) from the data between the first quarter of 2004 and the third quarter of 2022 in the FDA adverse event reporting system database (FAERS). Case reports of riluzole published in PubMed, Embase, and Web of Science before November 2022 were reviewed, and patient's data were extracted.

RESULTS

FAERS analysis identified 86 ADRs. Gastrointestinal system disorders and respiratory, thoracic, and mediastinal disorders account for 12 of the top 20 most frequent ADRs. Similarly, 9 of the 20 highest PRR ADRs were gastrointestinal system disorders and respiratory, thoracic, and mediastinal disorders. Twenty-two published riluzole-associated cases were identified in the literature. Respiratory, thoracic, and mediastinal disorders were the most commonly reported cases (n = 9), followed by gastrointestinal disorders, pancreatitis (n = 5).

CONCLUSIONS

Strong ADRs between riluzole and pancreatitis were identified, which reminds clinicians to monitor patients carefully. For patients with respiratory symptoms, clinicians should pay attention to distinguish the cause of their occurrence, and take appropriate measures. Beware that riluzole may increase the risk of inflammatory reactions and inappropriate vasopressin secretion and hyponatremia due to respiratory failure.

Pneumomediastinum while using mechanical insufflation-exsufflation after recovery from riluzole-induced interstitial lung disease

We, herein, report a 61-year-old male patient with amyotrophic lateral sclerosis (ALS) complicated pneumomediastinum while using mechanical insufflation-exsufflation (MI-E) after recovery from riluzole (RZ)-induced interstitial lung disease (RZ-ILD). After the treatment of RZ-ILD, he required non-invasive mechanical ventilation (NIV) at minimal pressure settings and MI-E to manage ALS-related breathing and airway-clearance issues, respectively. After a while, he developed progressive worsening dyspnoea, and chest computed tomography revealed extensive pneumomediastinum that had spread to the area surrounding the oesophagus, the retrosternal space, and the pericardial space. He was treated with immediate discontinuation of MI-E; however, he had to keep using NIV to support his severe respiratory muscle involvement. Pneumomediastinum gradually reduced in size and no recurrence of pneumomediastinum occurred. The clinical course of our patient suggests that excessive coughing associated with MI-E combined with his previous RZ-ILD, which potentially renders his lungs vulnerable to airway pressure, may have been the aetiological factors for secondary pneumomediastinum, i.e. barotrauma. Clinicians should be aware of the risk of pneumomediastinum while using MI-E in patients with ALS, who have other pre-existing risk factors for pneumomediastinum, such as drug-induced ILD in our case.

Riluzole for the treatment of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease caused by the death of motor neurons. Riluzole is a benzothiazole derivative that blocks glutamatergic neurotransmission in the CNS, which is thought to exert neuroprotective effects. Riluzole was approved by the US FDA in 1995 as the first drug to treat ALS. Although riluzole is generally safe and well tolerated in clinical practice, its efficacy in ALS is modest, prolonging tracheostomy-free survival by only 2-3 months. In this article, we will first provide an overview of the ALS field, followed by a discussion of riluzole regarding its physical properties; pharmacology; clinical efficacy in ALS; safety and tolerability; and recommended administration.