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Ritalin (Methylphenidate Hydrochloride) - Side Effects and Adverse Reactions



Nervousness and insomnia are the most common adverse reactions but are usually controlled by reducing dosage and omitting the drug in the afternoon or evening. Other reactions include hypersensitivity (including skin rash, urticaria, fever, arthralgia, exfoliative dermatitis, erythema multiforme with histopathological findings of necrotizing vasculitis, and thrombocytopenic purpura); anorexia; nausea; dizziness; palpitations; headache; dyskinesia; drowsiness; blood pressure and pulse changes, both up and down; tachycardia; angina; cardiac arrhythmia; abdominal pain; weight loss during prolonged therapy. There have been rare reports of Tourette’s syndrome. Toxic psychosis has been reported. Although a definite causal relationship has not been established, the following have been reported in patients taking this drug: instances of abnormal liver function, ranging from transaminase elevation to hepatic coma; isolated cases of cerebral arteritis and/or occlusion; leukopenia and/or anemia; transient depressed mood; aggressive behavior; a few instances of scalp hair loss. Very rare reports of neuroleptic malignant syndrome (NMS) have been received, and, in most of these, patients were concurrently receiving therapies associated with NMS. In a single report, a ten-year-old boy who had been taking methylphenidate for approximately 18 months experienced an NMS-like event within 45 minutes of ingesting his first dose of venlafaxine. It is uncertain whether this case represented a drug-drug interaction, a response to either drug alone, or some other cause.

In children, loss of appetite, abdominal pain, weight loss during prolonged therapy, insomnia, and tachycardia may occur more frequently; however, any of the other adverse reactions listed above may also occur.


Below is a sample of reports where side effects / adverse reactions may be related to Ritalin. The information is not vetted and should not be considered as verified clinical evidence.

Possible Ritalin side effects / adverse reactions in 8 year old male

Reported by a physician from Norway on 2011-10-04

Patient: 8 year old male

Reactions: Akathisia, Poisoning, Hallucination

Suspect drug(s):
    Dosage: unk ukn, unk
    Start date: 2011-09-22

    Dosage: 20 mg, unk

Possible Ritalin side effects / adverse reactions in 26 year old female

Reported by a individual with unspecified qualification from South Africa on 2011-10-12

Patient: 26 year old female

Reactions: Psychomotor Hyperactivity, Insomnia

Adverse event resulted in: hospitalization

Suspect drug(s):
    Dosage: 400 mg, daily
    Indication: Depressed Mood
    Start date: 2011-07-01
    End date: 2011-09-01

    Dosage: 80 mg, daily

Possible Ritalin side effects / adverse reactions in 15 year old male

Reported by a physician from United Kingdom on 2011-10-12

Patient: 15 year old male

Reactions: Delayed Puberty, Genital Disorder Male

Suspect drug(s):

See index of all Ritalin side effect reports >>

Drug label data at the top of this Page last updated: 2012-01-20

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