Methylphenidate HCl Side Effects

Possible side effects of methylphenidate are listed below. Call your doctor if the adverse effects are severe or persist after a few days.

• Irritability
• Nervousness
• Dizziness
• Trouble sleeping
• Stomach pain
• Heartburn
• Nausea
• Vomiting
• Diarrhea
• Decreased appetite
• Weight loss
• Headache
• Drowsiness
• Dry mouth
• Muscle tightness
• Uncontrolled movements
• Restlessness
• Excessive sweating
• Back pain
• Decreased libido (sexual desire)

Some of the adverse effects of methylphenidate are more serious. Call your doctor right away or seek emergency medical attention if you develop the following serious symptoms:

• Chest pain
• Irregular, fast, or pounding heartbeat
• Shortness of breath or difficulty breathing
• Excessive fatigue
• Fainting
• Speech problems
• Weakness or numbness in a limb
• Changes in vision such as blurred vision
• Seizures
• Agitation
• Delusions
• Paranoia
• Hallucinations
• Involuntary movements 
• Abnormal excitement or depressed mood
• Frequent and painful erections or erections that last more than 4 hours
• Pain, numbness, increased sensitivity, skin color changes, or wounds in the fingers and toes
• Fever
• Signs of allergic reactions (skin rash, hives, itching, blistering, peeling)
• Swelling of the face, eyes, lips, mouth, tongue, or throat
• Hoarseness
• Trouble breathing or swallowing

The above list may not include all the potential side effects of methylphenidate HCl. Contact your healthcare provider if the adverse reactions are unusual or severe or they do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Methylphenidate HCl Overdose: n case of an overdose of methylphenidate, call your doctor immediately. You can also call your local poison control center or the national poison control center at 1-800-222-1222. Symptoms of too much methylphenidate or too high doses may include nausea, vomiting, diarrhea, dizziness, fainting, restlessness, anxiety, agitation, blurred vision, fast breathing, uncontrolled shaking, muscle twitching, confusion, hallucinations, abnormal excitement, seizures, loss of consciousness, excessive sweating, flushing, headache, fever, fast or irregular heartbeat, widened pupils, dry mouth, dry nose, muscle weakness, or dark urine.

Source: FDA