Note: This document contains side effect information about methylphenidate. Some of the dosage forms listed on this page may not apply to the brand name Ritalin.

Applies to methylphenidate: oral capsule extended release, oral powder for suspension extended release, oral solution, oral tablet, oral tablet chewable, oral tablet extended release, oral tablet extended release chewable, oral tablet extended release disintegrating

Other dosage forms:

• transdermal patch extended release

Along with its needed effects, methylphenidate (the active ingredient contained in Ritalin) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking methylphenidate:

More common

• Fast heartbeat

Less common

• Chest pain
• fever
• joint pain
• skin rash or hives

Rare

• Black, tarry stools
• blood in the urine or stools
• blurred vision or other changes in vision
• crusting, dryness, or flaking of the skin
• muscle cramps
• pinpoint red spots on the skin
• scaling, severe redness, soreness, or swelling of the skin
• seizures
• uncontrolled vocal outbursts or tics (uncontrolled and repeated body movements)
• unusual bleeding or bruising

Incidence not known

• Confusion
• depression
• feeling like surroundings are not real
• numbness of the hands
• painful or difficult urination
• pale skin
• paleness or cold feeling in the fingertips and toes
• red, irritated eyes
• red, swollen, or scaly skin
• seeing, hearing, or feeling things that are not there
• severe or sudden headache
• sores, ulcers, or white spots on the lips or in the mouth
• sudden loss of coordination
• sudden slurring of speech
• tingling or pain in the fingers or toes when exposed to cold
• unusual behavior
• unusual tiredness or weakness
• weight loss
• yellow skin or eyes

Get emergency help immediately if any of the following symptoms of overdose occur while taking methylphenidate:

Symptoms of overdose

• Agitation
• anxiety
• bigger, dilated, or enlarged pupils of the eyes
• confusion as to time, place, or person
• dark-colored urine
• diarrhea
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• dry eyes, mouth, nose, or throat
• false or unusual sense of well-being
• fast, slow, irregular, pounding, or racing heartbeat or pulse
• holding false beliefs that cannot be changed by fact
• increased sensitivity of the eyes to light
• loss of consciousness
• muscle pain or stiffness
• muscle twitching
• nervousness
• overactive reflexes
• pounding in the ears
• rapid, shallow breathing
• sweating
• tremors
• unusual excitement, nervousness, or restlessness

Some side effects of methylphenidate may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• Headache
• loss of appetite
• nervousness
• stomach pain
• stuffy nose
• trouble sleeping
• unusually warm skin

Less common

• Anger
• decreased appetite
• dizziness
• drowsiness
• fear
• irritability
• muscle aches
• nausea
• runny nose
• scalp hair loss
• talking, feeling, and acting with excitement
• vomiting

Applies to methylphenidate: oral capsule extended release, oral powder for reconstitution extended release, oral solution, oral tablet, oral tablet chewable, oral tablet chewable extended release, oral tablet disintegrating extended release, oral tablet extended release, transdermal film extended release

The more commonly reported adverse reactions have included decreased appetite, abdominal pain, nausea, vomiting, dyspepsia, insomnia, weight loss, anxiety, dizziness, irritability, affect lability, tachycardia, and increased blood pressure.

Common (1% to 10%): Lethargy, ear infection, pyrexia, fatigue, ear and labyrinth disorders, asthenia, injury/poisoning/procedural complications

Postmarketing reports: Hyperpyrexia

Very common (10% or more): Psychiatric disorders (27.9%), insomnia (13.3%), irritability (11%)

Common (1% to 10%): Anxiety, restlessness, sleep disorder, agitation, affect lability, aggression, depression, depressed mood, abnormal behavior, bruxism, confusional state, initial insomnia, decreased libido, nervousness, emotional poverty, tension, panic attack

Uncommon (0.1% to 1%): Psychotic disorders, hallucinations (auditory, visual, tactile), anger, suicidal ideation, altered mood, mood swings, tearfulness, tics, worsening of pre-existing tics or Tourette's syndrome, hypervigilance

Rare (less than 0.1%): Mania, disorientation, libido disorder

Very rare (less than 0.01%): Suicidal attempt/completed suicide, transient depressed mood, abnormal thinking, apathy, repetitive behaviors, over-focusing

Frequency not reported: Delusions, thought disturbances, confessional state, logorrhea

Very common (10% or more): Decreased appetite (27.1%), metabolism and nutrition disorders (11.5%)

Common (1% to 10%): Anorexia, decreased weight, thirst

Very common (10% or more): Gastrointestinal disorders (23.5%), dry mouth (21.5%), nausea (12.2%), vomiting (10.2%)

Common (1% to 10%): Abdominal pain (upper and general), diarrhea, dyspepsia, toothache, stomach discomfort

Uncommon (0.1% to 1%): Constipation

Very common (10% or more): Nervous system disorders (23.5%), headache (23.2%)

Common (1% to 10%): Dizziness, dyskinesia, tremor, drowsiness, feeling jittery, psychomotor hyperactivity, somnolence, vertigo, paresthesia, motion sickness, tension headache

Uncommon (0.1% to 1%): Sedation, tremor

Very rare (less than 0.01%): Convulsions, choreoathetoid movements, reversible ischemic neurological deficit, cerebrovascular disorders (vasculitis, cerebral hemorrhages, cerebrovascular accidents, cerebral arteritis, cerebral occlusion), neuroleptic malignant syndrome (NMS)

Frequency not reported: Grand mal convulsions, migraine, sedation, serotonin syndrome (in combination with serotonergic drugs)

Common (1% to 10%): Reproductive system and breast disorders

Rare (less than 0.1%): Gynecomastia

Very common (10% or more): Nasopharyngitis (19.1%), respiratory/thoracic/mediastinal disorders (10.6%)

Common (1% to 10%): Upper respiratory tract infection, cough, oropharyngeal/pharyngolaryngeal pain, sinusitis, dyspnea

Among patients 7 to 10 years old, consistently medicated (i.e., receiving methylphenidate (the active ingredient contained in Ritalin) for 7 days per week) for over 14 months, as well as in naturalistic subgroups of newly methylphenidate-treated patients over 36 months (ages of 10 to 13 years), a temporary slowing in growth rate (on average, a total of about 2 cm less growth in height and 2.7 kg less growth in weight over 3 years), has been observed compared to non-medicated patients. This slowing in growth rate has been observed without evidence of growth rebound.

Very common (10% or more): Musculoskeletal and connective tissue disorders (14.4%),

Common (1% to 10%): Joint sprain, arthralgia

Uncommon (0.1% to 1%): Myalgia, muscle twitching, muscle tightness, muscle spasms

Very rare (less than 0.01%): Muscle cramps

Frequency not reported: Rhabdomyolysis, growth suppression, arthralgia

Very common (10% or more): Administration site and general disorders (12.9%)

Postmarketing reports: Patch application site reactions

Common (1% to 10%): Palpitations, tachycardia, cardiac disorders, vascular disorders, arrhythmias, hypertension, hot flush, changes in blood pressure and heart rate (usually an increase)

Uncommon (0.1% to 1%): Cardiac murmur

Rare (less than 0.1%): Angina pectoris

Very rare (less than 0.01%): Cardiac arrest, myocardial infarction, peripheral coldness, Raynaud's phenomenon, sudden cardiac death

Frequency not reported: Supraventricular tachycardia, bradycardia, ventricular extrasystoles, extrasystoles

Postmarketing reports: Angina pectoris, bradycardia extrasystole, supraventricular tachycardia, ventricular extrasystole, chest pain, chest discomfort

Common (1% to 10%): Rash, pruritus, urticaria, fever, scalp hair loss/alopecia, dermatitis, excoriation hyperhidrosis, skin and subcutaneous tissue disorders

Uncommon (0.1% to 1%): Angioneurotic edema, bullous conditions, exfoliative conditions

Rare (less than 0.1%): Macular rash, erythema

Very rare (less than 0.01%): Thrombocytopenic purpura, exfoliative dermatitis, erythema multiforme, fixed drug eruption

Very common (10% or more): Infections and infestations (45.2%)

Common (1% to 10%): Immune systems disorders, influenza

Common (1% to 10%): Eye disorders, eye pain

Uncommon (0.1% to 1%): Diplopia, blurred vision

Rare (less than 0.1%): Visual accommodation difficulties, mydriasis, visual disturbance

Frequency not reported: Dry eye

Postmarketing reports: Visual impairment, mydriasis, diplopia

Uncommon (0.1% to 1%): Hematuria, pollakiuria

Frequency not reported: Increased erection, prolonged erection, priapism

Uncommon (0.1% to 1%): Hepatic enzyme elevations

Very rare (less than 0.01%): Abnormal liver function, hepatic coma, increased blood alkaline phosphatase, increased blood bilirubin

Postmarketing reports: Hepatocellular injury, acute hepatic failure

Uncommon (0.1% to 1%): Hypersensitivity reactions (angioedema, anaphylaxis, auricular swelling, exanthemas)

Very rare (less than 0.01%): Leukopenia, thrombocytopenia, anemia, decreased platelet count, abnormal white blood count

Postmarketing reports: Pancytopenia, thrombocytopenia, thrombocytopenia purpura