 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  report side effects to Health Canada at 1-866-234-2345.The precautions of Methylphenidate HCl Oral: See also Warning section. Before taking methylphenidate, tell your doctor or pharmacist if you are allergic to it; or to dexmethylphenidate; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: high blood pressure, blood circulation problems (such as Raynaud's disease), glaucoma, heart problems (such as irregular heartbeat, heart failure, previous heart attack, problems with heart structure), family history of heart problems (such as sudden cardiac death, irregular heartbeat), mental/mood conditions (especially anxiety, tension, agitation), personal/family history of mental/mood disorders (such as bipolar disorder, depression, psychosis, suicidal thoughts), personal/family history of uncontrolled muscle movements (motor tics, Tourette's syndrome), overactive thyroid (hyperthyroidism), seizure disorder. This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. </s>