Flunarizine in Interstitial Lung Disease

Flunarizine should not be used in patients with interstitial lung disease due to the risk of exacerbating respiratory complications. 1

Evidence on Flunarizine and Pulmonary Concerns

Flunarizine is a calcium channel blocker that has been primarily studied and used for migraine prophylaxis, not for treatment of interstitial lung disease 1, 2
Cases of interstitial lung disease and pneumonitis have been reported with certain medications that affect similar pathways, and these can be fatal in susceptible patients 1
The NCCN guidelines specifically warn about the risk of interstitial lung disease and pneumonitis with certain medications, recommending discontinuation in patients who develop signs or symptoms of interstitial lung disease 1
Patients should be monitored for pulmonary symptoms when taking medications that may affect lung function 1

Current guidelines for idiopathic pulmonary fibrosis (IPF), a common form of interstitial lung disease, do not include flunarizine as a recommended treatment option 1
Several medications are specifically not recommended for IPF patients due to lack of efficacy or potential harm, including corticosteroid monotherapy (except during acute exacerbations), anticoagulants, colchicine, cyclosporine A, interferon, etanercept, bosentan, macitentan, and ambrisentan 1
Pirfenidone is recommended for patients with mild-to-moderate IPF under specialist supervision 1

Pre-existing lung disease is a risk factor for developing medication-induced interstitial lung disease 1
The British Association of Dermatologists' guidelines note that interstitial lung disease is a rare but serious complication of certain medications, and patients with pre-existing lung disease are at higher risk 1
Patients with interstitial lung disease should be monitored for respiratory symptoms, and any worsening should prompt immediate medical evaluation 1

Flunarizine has been associated with several adverse effects including sedation, weight gain, abdominal pain, depression, and extrapyramidal symptoms 1, 2, 3
Elderly patients are particularly susceptible to extrapyramidal effects of flunarizine 2, 3
The addition of medications with potential pulmonary toxicity to patients with pre-existing interstitial lung disease could increase the risk of respiratory deterioration 1

For migraine prophylaxis (the primary indication for flunarizine), alternative medications with established safety profiles should be considered for patients with interstitial lung disease 2, 4
First-line preventive options for migraine include beta-blockers, antidepressants, and anticonvulsants, which may have more favorable risk profiles for patients with interstitial lung disease 4
When treating patients with both interstitial lung disease and conditions that might benefit from flunarizine (such as migraine or vertigo), the potential risks of respiratory complications should be carefully weighed against potential benefits 1, 2, 5