SIDE EFFECTS: Nervousness, trouble sleeping, loss of appetite, weight loss, dizziness, nausea, vomiting, or headache may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. An empty tablet shell may appear in your stool. This effect is harmless because your body has already absorbed the medication. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high. Tell your doctor right away if you have any serious side effects, including: signs of blood flow problems in the fingers or toes (such as coldness, numbness, pain, or skin color changes), unusual wounds on the fingers or toes, fast/pounding/irregular heartbeat, mental/mood/behavior changes (such as agitation, aggression, mood swings, abnormal thoughts, thoughts of suicide), uncontrolled muscle movements (such as twitching, shaking), sudden outbursts of words/sounds that are hard to control, vision changes (such as blurred vision). Get medical help right away if you have any very serious side effects, including: fainting, seizure, symptoms of a heart attack (such as chest/jaw/left arm pain, shortness of breath, unusual sweating), symptoms of a stroke (such as weakness on one side of the body, slurred speech, sudden vision changes, confusion). Rarely, males (including young boys and teens) may have a painful or prolonged erection lasting 4 or more hours while using this medication. Caregivers/parents should also be watchful for this serious side effect in boys. If a painful or prolonged erection occurs, stop using this drug and get medical help right away, or permanent problems could occur. Ask your doctor or pharmacist for more details. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: 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, throat/stomach/intestinal problems (such as narrowing/blockage). This drug may make you dizzy. Alcohol or marijuana can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). If used for a long time, this drug may affect a child's growth rate, weight, and final adult height. To reduce the risk, the doctor may recommend briefly stopping the medication from time to time. Check the child's weight and height regularly, and consult your doctor or pharmacist for more details. Older adults may be more sensitive to the side effects of this drug, especially trouble sleeping, weight loss, or chest pain. During pregnancy, methylphenidate should be used only when clearly needed. Discuss the risks and benefits with your doctor. This medication passes into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication. Methylphenidate is very similar to dexmethylphenidate. Do not use medications containing dexmethylphenidate while using methylphenidate. This medication may interfere with certain medical/laboratory tests (including brain scan for Parkinson's disease), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: vomiting, agitation, confusion, sweating, flushing, muscle twitching, hallucinations, seizures, loss of consciousness.