• Tell all of your health care providers that you take Ritalin SR (methylphenidate controlled-release tablets). This includes your doctors, nurses, pharmacists, and dentists.
• Avoid driving and doing other tasks or actions that call for you to be alert until you see how Ritalin SR (methylphenidate controlled-release tablets) affects you.
• Heart attacks, strokes, and sudden deaths have happened in adults taking Ritalin SR (methylphenidate controlled-release tablets). Sudden deaths have also happened in children with some heart problems or heart defects. Call your doctor right away if you have a fast, slow, or abnormal heartbeat; weakness on 1 side of the body; trouble speaking or thinking; change in balance; drooping on 1 side of the face; change in eyesight; chest pain or pressure; shortness of breath; or severe dizziness or passing out.
• You may have some heart tests before starting Ritalin SR (methylphenidate controlled-release tablets). Talk with your doctor.
• Check blood pressure and heart rate as the doctor has told you. Talk with the doctor.
• This medicine may raise the chance of seizures in some people, including people who have had seizures in the past. Talk to your doctor to see if you have a greater chance of seizures while taking Ritalin SR (methylphenidate controlled-release tablets).
• Avoid drinking alcohol while taking Ritalin SR (methylphenidate controlled-release tablets).
• A very bad and sometimes deadly health problem called serotonin syndrome may happen if you take Ritalin SR (methylphenidate controlled-release tablets) with drugs for depression, migraines, or certain other drugs. Call your doctor right away if you have agitation; change in balance; confusion; hallucinations; fever; fast or abnormal heartbeat; flushing; muscle twitching or stiffness; seizures; shivering or shaking; sweating a lot; very bad diarrhea, upset stomach, or throwing up; or very bad headache.
• Rarely, low blood cell counts have happened with Ritalin SR (methylphenidate controlled-release tablets). Call your doctor right away if you have any unexplained bruising or bleeding; signs of infection like fever, chills, or sore throat; or feel very tired or weak.
• This medicine may affect growth in children and teens in some cases. They may need regular growth checks. Talk with the doctor.
• Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

Use Ritalin SR (methylphenidate controlled-release tablets) as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• Take in the morning.
• Some drugs may need to be taken with food or on an empty stomach. For some drugs it does not matter. Check with your pharmacist about how to take Ritalin SR (methylphenidate controlled-release tablets).
• Swallow whole. Do not chew, break, or crush.
• If you have been taking Ritalin SR (methylphenidate controlled-release tablets) for a long time or at high doses, it may not work as well and you may need higher doses to get the same effect. This is known as tolerance. Call your doctor if Ritalin SR (methylphenidate controlled-release tablets) stops working well. Do not take more than ordered.
• Limit your use of caffeine (for example, tea, coffee, cola) and chocolate. Use with Ritalin SR (methylphenidate controlled-release tablets) may cause nervousness, shakiness, and a fast heartbeat.
• Have your blood work checked if you are on Ritalin SR (methylphenidate controlled-release tablets) for a long time. Talk with your doctor.
• If you are taking Ritalin SR (methylphenidate controlled-release tablets) and have high blood pressure, talk with your doctor before using OTC products that may raise blood pressure. These include cough or cold drugs, diet pills, stimulants, ibuprofen or like products, and some natural products or aids.

What do I do if I miss a dose?

• Skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.

See also:

Ritalin-SR dosage information (in more detail)

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of high blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
• Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
• Joint pain.
• Purple patches on the skin or mouth.
• Change in eyesight.
• Seizures.
• Shakiness.
• Trouble controlling body movements.
• Sweating a lot.
• Restlessness.
• Change in color of hands or feet from pale to blue or red.
• Numbness, pain, tingling, or cold feeling of the hands or feet.
• Any sores or wounds on the fingers or toes.
• Muscle pain or weakness, dark urine, or trouble passing urine.
• Change in sex interest.
• Call your doctor right away if you have a painful erection (hard penis) or an erection that lasts for longer than 4 hours. This may happen even when you are not having sex. If this is not treated right away, it may lead to lasting sex problems and you may not be able to have sex.
• New or worse behavior and mood changes like change in thinking, anger, and hallucinations have happened with Ritalin SR (methylphenidate controlled-release tablets). Tell your doctor if you or a family member have any mental or mood problems like low mood (depression) or bipolar illness, or if a family member has killed themselves. Call your doctor right away if you have hallucinations; change in the way you act; or signs of mood changes like low mood (depression), thoughts of killing yourself, nervousness, emotional ups and downs, thinking that is not normal, anxiety, or lack of interest in life.