Methylphenidate hydrochloride extended-release tablets can be used for the treatment of attention deficit hyperactivity disorder, episodic somnambulism and so on. 1. Attention Deficit Hyperactivity Disorder (ADHD): It is mainly applied to primary ADHD, its specific mechanism of action is unknown, but it is generally believed to act on the dopamine transporter in the cerebral cortex, which can block the function of dopamine uptake synapses, thus alleviating the condition; 2. Episodic somnolence: Methylphenidate Hydrochloride Extended-Release Tablets is a kind of neuroleptic, which can stimulate the nerves and alleviate the drowsiness symptoms of patients, so it is also used in clinics to treat episodic somnolence. Adverse effects of the drug include, but are not limited to, decreased appetite, upper respiratory tract infections, and sinusitis. It is important to note that it is contraindicated in patients with significant symptoms of anxiety, nervousness and agitation, and in those who are allergic to the drug. Methylphenidate Hydrochloride Extended-Release Tablets is a psychotropic controlled drug with certain side effects, and should be used under the guidance of a doctor.