Flunarizine is a calcium antagonist, mainly used in the treatment of cerebrovascular disease, migraine, tinnitus. Flunarizine needs to be used under the guidance of a doctor, otherwise it may jeopardize the central nervous system and muscle tone, with drowsiness, extrapyramidal symptoms and muscle weakness; in addition, Flunarizine has the side effect of gastrointestinal discomfort. 1. Central nervous system: Flunarizine inhibits calcium inward flow in brain cells, most often causing the adverse effects of drowsiness and fatigue while dilating blood vessels to relieve cerebrovascular disease. Flunarizine also often cause extrapyramidal symptoms, manifested as bradykinesia, inability to sit still, jaw dyskinesia, tremor, ankylosis and so on. In addition, long-term use of flunarizine may also develop depression. 2. Muscle weakness: Flunarizine may inhibit the contraction of muscle cells while inhibiting brain cells, reducing muscle tone and thus showing symptoms of muscle weakness. Muscle weakness is mostly seen in the elderly, and most of them have dull face, swallowing disorder, and even voluntary respiratory disorder. 3. Gastrointestinal discomfort: after taking Flunarizine, gastric reactions such as burning sensation in the stomach, hypergastrulation, increased food intake and weight gain may occur. It should be noted that Flunarizine is a prescription drug and must be used under the guidance of a doctor. Patients who are engaged in occupations that require a high degree of concentration, such as working at heights or driving for long periods of time, should not work while using Flunarizine to avoid danger.