Active substance: The active substance is methylphenidate hydrochloride.
One Ritalin tablet contains 10 mg methylphenidate hydrochloride.
Active Moiety: Methylphenidate (INN for alpha-phenyl-2-piperidine acetic acid methyl ester).
Excipients/Inactive Ingredients: Ritalin tablet [10 mg]: calcium phosphate, lactose, wheat starch, gelatin, magnesium stearate, talc.
Pharmacotherapeutic Group: Psychostimulants. ATC Code: NO6B AO4.
Pharmacology: Pharmacodynamics: Mechanism of Action: Ritalin is a racemate consisting of a 1:1 mixture of d-methylphenidate (d-MPH) and l-methylphenidate (l-MPH).
Ritalin is a mild CNS stimulant with more prominent effects on mental than on motor activities. Its mode of action in man is not completely understood, but its stimulant effects are thought to be due to an inhibition of dopamine reuptake in the striatum, without triggering the release of dopamine.
The mechanism by which Ritalin exerts its mental and behavioural effects in children is not clearly established, nor is there conclusive evidence showing how these effects relate to the condition of the central nervous system.
The l-enantiomer is thought to be pharmacologically inactive.
The effect of treatment with 40 mg dexmethylphenidate hydrochloride, the pharmacologically active d-enantiomer of Ritalin, on QT/QTc interval was evaluated in a study in 75 healthy volunteers. The maximum mean prolongation of QTcF intervals was <5 ms, and the upper limit of the 90% confidence interval was below 10 ms for all time matched comparisons versus placebo. This was below the threshold of clinical concern and no exposure response relationship was evident.
Clinical studies: Ritalin has been used for over 50 years in the treatment of ADHD. Its effectiveness in the treatment of ADHD is well established. In addition to improving core symptoms of ADHD, methylphenidate also improves behaviours associated with ADHD such as impaired academic performance and social function.
Studies in the published literature have shown Ritalin to significantly improve daytime sleepiness and cataplexy.
Pharmacokinetics: Absorption: Tablets: After oral administration the active substance (methylphenidate hydrochloride) is rapidly and almost completely absorbed. Owing to extensive first-pass metabolism, the absolute bioavailability was 22±8 % for the d-enantiomer and 5±3 % for the l-enantiomer. Ingestion with food has no relevant effect on absorption. Peak plasma concentrations of about 40 nmol/L (11 ng/mL) are reached on average 1 to 2 hours after administration. Peak plasma concentrations vary markedly between patients. The area under the concentration-time curve (AUC), and the peak plasma concentration (Cmax) are proportional to the dose.
Distribution: In blood, methylphenidate and its metabolites are distributed between plasma (57 %) and erythrocytes (43 %). Binding to plasma proteins is low (10 to 33 %). The volume of distribution was 2.65±1.11 L/kg for d-MPH and 1.80±0.91 L/kg for l-MPH.
Methylphenidate excretion into breast milk has been noted in two case reports, where the calculated relative infant dose was ≤0.2% of the weight adjusted maternal dose. Adverse events were not noted in either infant (6 months of age and 11 months of age).
Biotransformation/metabolism: Biotransformation of methylphenidate by the carboxylesterase CES1A1 is rapid and extensive. Peak plasma concentrations of the main, deesterified, metabolite - alpha-phenyl-2-piperidine acetic-acid (ritalinic acid) - are attained about 2 hours after administration and are 30 to 50 times higher than those of the unchanged substance. The half-life of alpha-phenyl-2-piperidine acetic acid is about twice that of methylphenidate, and its mean systemic clearance is 0.17 L/h/kg. Only small amounts of hydroxylated metabolites (e.g. hydroxymethylphenidate and hydroxyritalinic acid) are detectable. Therapeutic activity seems to be principally due to the parent compound.
Elimination: Methylphenidate is eliminated from the plasma with a mean half-life of 2 hours. The systemic clearance is 0.40±0.12 L/h/kg for d-MPH and 0.73±0.28 L/h/kg for l-MPH. After oral administration, 78 to 97 % of the dose is excreted in the urine and 1 to 3 % in the faeces in the form of metabolites within 48 to 96 hours. Only small quantities (< 1 %) of unchanged methylphenidate appear in the urine. Most of the dose is excreted in the urine as alpha-phenyl-2-piperidine acetic acid (60 to 86 %).
Special populations: Effect of age: There are no apparent differences in the pharmacokinetics of methylphenidate between hyperactive children and healthy adult volunteers.
Patients with renal impairment: Elimination data from patients with normal renal function suggest that renal excretion of unchanged methylphenidate would hardly be diminished in the presence of impaired renal function. However, renal excretion of the metabolite alpha-phenyl-2-piperidine acetic acid may be reduced.
Toxicology: Non-Clinical Safety Data: Reproductive toxicity: See PREGNANCY, LACTATION AND FEMALES AND MALES OF REPRODUCTIVE POTENTIAL under Use in Pregnancy & Lactation.
Fertility: Methylphenidate did not impair fertility in male or female mice that were fed diets containing the drug in an 18-week continuous breeding study. The study was conducted over two generations of mice continuously receiving methylphenidate doses of up to 160 mg/kg/day (about 90-fold higher than the MRHD on a mg/kg basis).
Carcinogenicity: In a lifetime carcinogenicity study carried out in B6C3F1 mice, methylphenidate caused an increase in hepatocellular adenomas (a benign tumour) and, in males only, an increase in hepatoblastomas (a malignant tumour) at daily doses of approximately 60 mg/kg/day about 35-fold-higher than the maximum recommended human dose (MRHD) on a mg/kg basis. Hepatoblastoma is a relatively rare rodent malignant tumour type. There was no overall increase in the number of malignant hepatic tumours. The mouse strain used is particularly sensitive to the development of hepatic tumours. It is thought that hepatoblastomas might be due to non-genotoxic mechanisms such as an increase in hepatic cell proliferation. This is consistent with the increase in liver weights observed in this mouse carcinogenicity study.
Methylphenidate did not cause any increase in tumours in a lifetime carcinogenicity study carried out in F344 rats; the highest dose used was approximately 45 mg/kg/day (about 26-fold higher than the MRHD on a mg/kg basis).
Genotoxicity: With methylphenidate, sister chromatid exchange and chromosome aberrations were elevated in one in vitro study in Chinese Hamster Ovary (CHO) cells. However, no genotoxicity effects were seen in several other assays, including no mutagenic effects in three in vitro tests (Ames reverse mutation test, mouse lymphoma forward mutation test, human lymphocyte chromosome aberration test) and no evidence of clastogenic or aneugenic effects in two in vivo mouse bone marrow micronucleus tests, at doses up to 250 mg/kg. B6C3F1 mice from the same strain that showed liver tumours in the cancer bioassay were used in one of these studies. Additionally, there was no genotoxic potential as assessed by measuring cII mutations in the liver and micronuclei in peripheral reticulocytes in the Big Blue mouse, micronuclei in peripheral blood reticulocytes, HPRT mutations and chromosomal aberrations in peripheral blood lymphocytes of rhesus monkeys, Pig A locus mutations in adolescent rats, micronucleated reticulocyte frequencies in blood and DNA damage in blood, brain, and liver cells of adult male rats treated for 28 consecutive days, and by measuring micronuclei in mouse peripheral blood erythrocytes.
Juvenile toxicity: In a conventional study conducted in young rats, methylphenidate was administered orally at doses of up to 100 mg/kg/day for 9 weeks, starting early in the postnatal period (postnatal day 7) and continuing through sexual maturity (postnatal week 10). When the animals were tested as adults (postnatal weeks 13-14), decreased spontaneous locomotor activity was observed in males and females previously treated with 50 mg/kg/day or greater, and a deficit in the acquisition of a specific learning task was seen in females exposed to the highest dose of 100 mg/kg/day (about 58-fold higher than the MRHD on a mg/kg basis). The clinical relevance of these findings is unknown.
Ritalin 10 tablets are indicated for the treatment of ADHD. Ritalin 10 tablets are also indicated for the treatment of narcolepsy.
Attention-Deficit Hyperactivity Disorder (ADHD): ADHD was previously known as attention-deficit disorder. Other terms used to describe this behavioral syndrome include: minimal brain dysfunction in children, hyperkinetic child syndrome, minimal brain damage, minimal cerebral dysfunction, minor cerebral dysfunction and psycho-organic syndrome of children.
Ritalin 10 is indicated as an integral part of a total treatment program for ADHD that may include other measures (psychological, educational and social) for patients with this syndrome. Stimulants are not intended for use in the patient who exhibits symptoms secondary to environmental factors and/or other primary psychiatric disorders, including psychosis.
Special Diagnostic Considerations for ADHD in children: The aetiology of this syndrome is unknown and there is no single diagnostic test. Adequate diagnosis requires the use, not only of medical, but also of psychological, educational and social resources. Characteristics commonly reported include: chronic history of short attention span, distractibility, emotional lability, impulsivity, moderate to severe hyperactivity, minor neurological signs and an abnormal EEG. Learning may or may not be impaired. The diagnosis must be based upon a complete history and evaluation of the child and not solely on the presence of one or more of these characteristics.
Drug treatment is not indicated for all children with this syndrome. Stimulants are not intended for use in children who exhibit symptoms secondary to environmental factors (e.g. child abuse in particular) or primary psychiatric disorders. Appropriate educational placement is essential and psychosocial intervention is generally necessary. When remedial measures alone are insufficient, the decision to prescribe stimulant medicine will depend upon the physician's assessment of the chronicity and severity of the child's symptoms.
Continuation of Treatment in Adolescent and Special Diagnostic Considerations for ADHD in adults: There is limited information to guide clinicians about how long older adolescents should continue to receive treatment with drugs for attention deficit hyperactivity disorder (ADHD). The decision should be based on the extent to which symptoms of ADHD and social functioning have improved to a point that medication is no longer needed. If older adolescents have been largely symptoms-free for a year and are functioning well, a trial without medication is warranted. This should be undertaken at times of low stress such as during holidays or in a period when a school routine is well established.
ADHD needs to be considered in adults who present with longstanding symptoms suggestive of ADHD (inattention, impulsivity, disorganization) that appear to have started in childhood and are persisting into adult life. Further, people with personality disorder and/or problems with drug use accompanied by a significant level of impulsivity and inattention should be referred for evaluation by a psychiatrist with the training and skills required to assess and treat ADHD. This expertise is necessary due to the overlap of ADHD symptoms with anxiety, mood and personality disorders.
Narcolepsy (Ritalin only): The symptoms include daytime sleepiness, inappropriate sleep episodes and rapidly occurring loss of voluntary muscle tone. Ritalin 10 is effective for symptoms of sleepiness but not for loss of voluntary muscle tone.
Pre-treatment screening: Treatment should only be initiated by specialist physicians with experience in the use of the drug. Before initiating Ritalin 10 treatment, patients should be assessed for pre-existing cardiovascular and psychiatric disorders and a family history of sudden death, ventricular arrhythmia and psychiatric disorders. Weight and height should also be measured before treatment and documented on a growth chart (see CONTRAINDICATIONS and PRECAUTIONS).
Dosage regimen: The dosage of Ritalin 10 should be individualized according to the patient's clinical needs and responses.
Treatment with Ritalin 10 should be initiated at a low dose, with increments at weekly intervals.
ADHD: In the treatment of ADHD, an attempt should be made to time administration of the drug to coincide with periods of greatest academic, behavioural, or social difficulties for the patient.
If symptoms do not improve after dose titration over a one-month period, the drug should be discontinued.
If symptoms worsen or other adverse effects occur, the dosage should be reduced or, if necessary, the drug discontinued.
If the effect of the drug wears off too early in the evening, disturbed behaviour and/or inability to go to sleep may recur. A small evening dose of Ritalin 10mg tablet may help solve this problem.
Periodic assessment of the treatment in ADHD: Drug treatment does not need to be indefinite. Physicians should periodically re-evaluate the treatment with trial periods off medication to assess the patient's functioning without pharmacotherapy. Improvement may be sustained when the drug is either temporarily or permanently discontinued. When used in children with ADHD, treatment can usually be discontinued during or after puberty.
If therapy is interrupted for reasons other than those stated above, it should not be restarted at the dose that had been reached prior to treatment interruption, but should be re-titrated.
Children and adolescents (6 years and over): Ritalin 10 tablets: Start with 5 mg once or twice daily (e.g. at breakfast and at lunch) with gradual increments of 5 or 10 mg weekly. The total daily dosage should be administered in divided doses.
In some children with ADHD, sleeplessness may occur as the effect of the drug wears off. On rare occasions, an additional dose at about 8.00 p.m. may help; a trial dose may help to clarify the issue in an individual case, if the symptom warrants treatment.
Narcolepsy: Ritalin 10: Adults: Administer the tablets in divided doses 2 or 3 times daily. The average dose is 20 to 30 mg daily. Some patients may require 40 to 60 mg daily. In others, 10 to 15 mg daily will be adequate. Patients who are unable to sleep if Ritalin 10 tablets are taken late in the day should take the last dose before 6 p.m.
Dosing for each patient requires titration to control symptoms. Single doses greater than 20 mg are associated with sympathomimetic side effects. Therefore, the average single dose should be less than 20mg. A maximum total dose of 60 mg/day may be required.
Maximum daily doses: A maximum daily dose of 60 mg should not be exceeded for the treatment of narcolepsy.
Administration: Ritalin 10 tablets: The rate of absorption and, therefore, onset of action is faster when Ritalin 10 tablets are taken with food. Dosage should, therefore, be standardized in relation to food to ensure consistency of effect.
Doses should be administered 1-2 hours before the maximum effect is required.
Signs and symptoms: Signs and symptoms of acute over dosage, mainly due to overstimulation of the central and sympathetic nervous systems, may include: vomiting, agitation, tremor, hyperreflexia, muscle twitching, convulsions (possibly followed by coma), euphoria, confusion, hallucinations, delirium, sweating, flushing, headache, hyperpyrexia, tachycardia, palpitation, cardiac arrhythmias, hypertension, mydriasis, dryness of mucous membranes and rhabdomyolysis.
Management: Management consists in providing supportive measures, and symptomatic treatment of life-threatening events, e.g. hypertensive crisis, cardiac arrhythmias, convulsions. For the most current guidance for treatment of symptoms of overdose, the practitioner should consult a certified Poison Control Center or current toxicological publication.
Supportive measures include preventing self-injury and protecting the patient from external stimuli that would exacerbate the overstimulation already present. If the overdose is oral and the patient is conscious, the stomach could be evacuated by induction of vomiting, followed by administration of activated charcoal. Airway protected gastric lavage is necessary in hyperactive or unconscious patients, or those with depressed respiration. Intensive care must be provided to maintain adequate circulation and respiratory exchange; external cooling procedures may be required to reduce hyperpyrexia.
The efficacy of peritoneal dialysis or extracorporeal haemodialysis for Ritalin over dosage has not been established. Clinical experience with acute over dosage is limited. Patients who have received doses higher than those recommended should be carefully monitored. In the event of overdose leading to clinically significant hypocalcaemia, reversal may be achieved with supplemental oral calcium and/or an infusion of calcium gluconate.
Hypersensitivity to methylphenidate or to any of the excipients.
Pre-existing cardiovascular disorders including severe hypertension, angina, arterial occlusive disease; heart failure, haemodynamically significant congenital heart disease, cardiomyopathies, myocardial infarction, potentially life-threatening arrhythmias and channelopathies (disorders caused by the dysfunction of ion channels).
During treatment with monoamine oxidase (MAO) inhibitors, or within a minimum of 2 weeks of discontinuing those drugs, due to risk of hypertensive crisis (see INTERACTIONS).
Diagnosis or family history of Tourette's syndrome.
General: Treatment with Ritalin is not indicated in all cases of Attention-Deficit/Hyperactivity disorder, and should be considered only after detailed history-taking and evaluation. The decision to prescribe Ritalin should depend on an assessment of the severity of symptoms and, in paediatric patients, their appropriateness to the child's age, and not simply on the presence of one or more abnormal behavioural characteristics. Where these symptoms are associated with acute stress reactions, treatment with Ritalin is usually not indicated.
Cardiovascular: Pre-existing Structural Cardiac Abnormalities or Other Serious Heart Problems: Sudden death has been reported in association with the use of stimulants of the central nervous system at usual doses in patients with structural cardiac abnormalities or other serious problems. A causal relationship with stimulant products has not been established since some of these conditions alone may carry an increased risk of sudden death. Stimulant products, including Ritalin, generally should not be used in patients with known structural cardiac abnormalities or other serious cardiac disorders that may increase the risk of sudden death due to sympathomimetic effects of a stimulant drug. Before initiating Ritalin treatment, patients should be assessed for pre-existing cardiovascular disorders and a family history of sudden death and ventricular arrhythmia (see DOSAGE & ADMINISTRATION).
Cardiovascular Conditions: Ritalin is contraindicated in patients with severe hypertension. Ritalin increases heart rate and systolic and diastolic blood pressure. Therefore, caution is indicated in treating patients whose underlying medical conditions might be compromised by increases in blood pressure or heart rate, e.g., those with pre-existing hypertension. Severe cardiovascular disorders are contraindicated (see CONTRAINDICATIONS).
Blood pressure should be monitored at appropriate intervals in all patients taking Ritalin, especially those with hypertension. Patients who develop symptoms suggestive of cardiac disease during Ritalin treatment should undergo a prompt cardiac evaluation.
Misuse and Cardiovascular Events: Misuse of stimulants of the central nervous system, including Ritalin, may be associated with sudden death and other serious cardiovascular adverse events.
Cerebrovascular: Cerebrovascular conditions: Patients with pre-existing central nervous system (CNS) abnormalities, e.g., cerebral aneurysm and/or other vascular abnormalities such as vasculitis or pre-existing stroke should not be treated with Ritalin. Patients with additional risk factors (history of cardiovascular disease, concomitant medications that elevate blood pressure) should be assessed regularly for neurological/psychiatric signs and symptoms after initiating treatment with Ritalin (see previously mentioned on Cardiovascular Conditions and INTERACTIONS).
Psychiatric: Co-morbidity of psychiatric disorders in ADHD is common and should be taken into account when prescribing stimulant products. Prior to initiating treatment with Ritalin, patients should be assessed for pre-existing psychiatric disorders and a family history of psychiatric disorders (see DOSAGE & ADMINISTRATION).
Treatment of ADHD with stimulant products including Ritalin should not be initiated in patients with acute psychosis, acute mania or acute suicidality. These acute conditions should be treated and controlled before ADHD treatment is considered.
In the case of emergent psychiatric symptoms or exacerbation of pre-existing psychiatric symptoms, Ritalin should not be given to patients unless the benefit outweighs the potential risk.
Psychotic symptoms: Psychotic symptoms, including visual and tactile hallucinations or mania have been reported in patients administered usual prescribed doses of stimulant products, including Ritalin (see ADVERSE REACTIONS). Physicians should consider treatment discontinuation.
Aggressive behaviour: Emergent aggressive behaviour or an exacerbation of baseline aggressive behaviour has been reported during stimulant therapy, including Ritalin. However, patients with ADHD may experience aggression as part of their medical condition. Therefore causal association with treatment is difficult to assess. Physicians should evaluate the need for adjustment of treatment regimen in patients experiencing these behavioural changes, bearing in mind that upwards or downwards titration may be appropriate. Treatment interruption can be considered.
Suicidal tendency: Patients with emergent suicidal ideation and behaviour during treatment for ADHD should be evaluated immediately by their physician. The physician should initiate appropriate treatment of the underlying psychiatric condition and consider a possible change in the ADHD treatment regimen.
Tics: Ritalin is associated with the onset or exacerbation of motor and verbal tics. Worsening of Tourette's syndrome has also been reported (see ADVERSE REACTIONS). Family history should be assessed and clinical evaluation for tics or Tourette's syndrome in patients should precede use of methylphenidate for ADHD treatment. Ritalin is contraindicated in case of diagnosis or family history of Tourette's syndrome (see CONTRAINDICATIONS). Patients should be regularly monitored for the emergence or worsening of tics during treatment with Ritalin.
Serotonin syndrome: Serotonin syndrome has been reported following co-administration of methylphenidate with serotonergic drugs such as selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). The concomitant use of methylphenidate and serotonergic drugs is not recommended as this may lead to the development of serotonin syndrome. The symptoms of serotonin syndrome may include mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhoea). Prompt recognition of these symptoms is important so that treatment with methylphenidate and serotonergic drugs can be immediately discontinued and appropriate treatment instituted (see Interactions).
Priapism: Prolonged and painful erections, sometimes requiring surgical intervention, have been reported with methylphenidate products in both paediatric and adult patients. Priapism generally developed after some time on the drug, often subsequent to an increase in dose. Priapism has also been reported during a period of drug withdrawal (drug holidays or during discontinuation). Patients who develop abnormally sustained or frequent and painful erections should seek immediate medical attention.
Growth retardation: Moderately reduced weight gain and slight growth retardation have been reported with the long-term use of stimulants, including Ritalin, in children (see ADVERSE REACTIONS). Growth should be monitored as clinically necessary during treatment with Ritalin, and patients who are not growing or gaining height or weight as expected may need to have their treatment interrupted.
Seizures: Ritalin should be used with caution in patients with epilepsy as clinical experience has shown that it can cause an increase in seizure frequency in a small number of such patients. If seizure frequency increases, Ritalin should be discontinued.
Drug abuse and dependence: Chronic abuse of Ritalin can lead to marked tolerance and psychological dependence with varying degrees of abnormal behaviour. Frank psychotic episodes may occur, especially with parenteral abuse. Clinical data indicate that children given Ritalin are not more likely to abuse drugs as adolescents or adults.
Caution is called for in emotionally unstable patients, such as those with a history of drug dependence or alcoholism, because they may increase the dosage on their own initiative.
Withdrawal: Careful supervision is required during drug withdrawal, since this may unmask depression as well as the effects of chronic over activity. Some patients may require long-term follow-up.
Haematological effects: The long-term safety and efficacy profiles of Ritalin are not fully known. Patients requiring long-term therapy should therefore be carefully monitored and complete and differential blood counts and a platelet count performed periodically. In the event of haematological disorders appropriate medical intervention should be considered (see ADVERSE REACTIONS).
Paediatric patients under 6 years of age: Ritalin should not be used in children under 6 years of age, since safety and efficacy in this age group have not been established.
Driving and using machines: Ritalin may cause dizziness, drowsiness, blurred vision, hallucinations or other CNS side effects (see ADVERSE REACTIONS). Patients experiencing such side effects should refrain from driving, operating machinery, or engaging in other potentially hazardous activities.
Pregnancy: There is insufficient experience with use of methylphenidate in pregnant women. Ritalin should not be given to pregnant women unless the potential benefit outweighs the risk to the foetus. Methylphenidate is potentially teratogenic in rabbits.
Animal data: Methylphenidate is considered to be possibly teratogenic in rabbits. Spina bifida with malrotated hind limbs was observed in two separate litters at a dose of 200 mg/kg/day. Exposure (AUC) at this dose was approximately 5.1 times higher than the extrapolated exposure at the MRHD. Exposure at the next lower dose, wherein no spina bifida was found, was 0.7 times the extrapolated exposure at MRHD. A second study was conducted with a high dose of 300 mg/kg, which was considered maternally toxic. No spina bifida was seen in 12 litters (92 fetuses) surviving. Exposure (AUC) at 300 mg/kg was 7.5 times the extrapolated exposure at MRHD.
Methylphenidate is not teratogenic in rats. Development fetal toxicity was noted at a high dose of 75 mg/kg (20.9 times higher than the exposure (AUC) at MRHD) and consisted of an increase of the instance of fetuses with delayed ossification of the skull and hyoid bones as well as fetuses with short supernumerary ribs.
When methylphenidate was administered to rats throughout pregnancy and lactation at doses of up to 45 mg/kg/day (about 26-fold higher than the MRHD on a mg/kg basis), offspring body weight gain was decreased at the highest dose, but no other effects on postnatal development were observed.
Lactation: Case reports showed that methylphenidate was distributed into breast milk reaching a milk-to-plasma ratio of approximately 2.5 (see PHARMACOLOGY: Pharmacokinetics under Actions).
A decision should be made whether to abstain from breast-feeding or to abstain from Ritalin therapy, taking into account the benefit of breast-feeding to the child and the benefit of therapy to the woman.
Females and males of reproductive potential: There are no data to support special recommendation in women of child-bearing potential.
Infertility: No human data on the effect of methylphenidate on fertility are available. Methylphenidate did not impair fertility in male or female mice (see Pharmacology: Toxicology: NON-CLINICAL SAFETY DATA under Actions).
Nervousness and insomnia are very common adverse reactions which occur at the beginning of Ritalin treatment but can usually be controlled by reducing the dosage and/or omitting the afternoon or evening dose.
Decreased appetite is also very common but usually transient. Abdominal pain, nausea and vomiting are common to very common, usually occur at the beginning of treatment and may be alleviated by concomitant food intake.
Tabulated summary of adverse drug reactions:
Adverse drug reactions (Table 1) are listed by MedDRA system organ class. Within each system organ class, the adverse drug reactions are ranked by frequency, with the most frequent reactions first. Within each frequency grouping, adverse drug reactions are presented in order of decreasing seriousness. In addition, the corresponding frequency category for each adverse drug reaction is based on the following convention (CIOMS III): very common (≥1/10); common (≥1/100 to <1/10); uncommon (≥1/1,000 to <1/100); rare (≥1/10,000 to <1/1,000); very rare (<1/10,000). (See Table 1.)
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Very rare reports of poorly documented neuroleptic malignant syndrome (NMS) have been received. In most of these reports, patients were also receiving other medications. It is uncertain what role Ritalin played in these cases.
Adverse drug reactions from spontaneous reports and literature cases (frequency not known):
The following adverse drug reactions have been derived from post-marketing experience with Ritalin via spontaneous case reports and literature cases. Because these reactions are reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency which is therefore categorized as not known. Adverse drug reactions are listed according to system organ classes in MedDRA. Within each system organ class, ADRs are presented in order of decreasing seriousness. (See Table 2.)
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Additional adverse reactions reported with other methylphenidate-containing products:
The list as follows shows adverse reactions not listed for Ritalin (see Table 1) that have been reported with other methylphenidate-containing products based on clinical studies data and post-marketing spontaneous reports.
Blood and lymphatic disorders:
Immune system disorders:
Hypersensitivity reactions such as auricular swelling.
Irritability, aggression, affect lability, abnormal behaviour or thinking, anger, suicidal ideation or attempt (including completed suicide), mood altered, mood swings, hypervigilance, mania, disorientation, libido disorder, apathy, repetitive behaviours, over-focusing, confusional state, dependence. Cases of abuse and dependence have been described, more often with immediate-release formulations.
Nervous system disorders:
Reversible ischemic neurological deficit, migraine.
Diplopia, mydriasis, visual disturbance.
Cardiac arrest, myocardial infarction.
Peripheral coldness, Raynaud's phenomenon.
Respiratory, thoracic and mediastinal disorders:
Pharyngolaryngeal pain, dyspnoea.
Skin and subcutaneous tissue disorders:
Angioneurotic oedema, erythema, fixed drug eruption.
Musculoskeletal, connective tissue and bone disorders:
Myalgia, muscle twitching.
Renal and urinary disorders:
Reproductive system and breast disorders:
General disorders and administration site conditions:
Chest pain, fatigue, sudden cardiac death.
Pharmacodynamic interactions: Anti-hypertensive drugs: Ritalin may decrease the effectiveness of drugs used to treat hypertension.
Use with drugs that elevate blood pressure: Ritalin should be used with caution in patients being treated with drugs that elevate blood pressure (see also paragraph on Cerebrovascular Conditions in PRECAUTIONS).
Because of possible hypertensive crisis, Ritalin is contraindicated in patients being treated (currently or within the preceding 2 weeks) with MAO inhibitors (see CONTRAINDICATIONS).
Use with alcohol: Alcohol may exacerbate the adverse CNS effects of psychoactive drugs, including Ritalin. It is therefore advisable for patients to abstain from alcohol during treatment.
Use with anaesthetics: There is a risk of sudden blood pressure and heart rate increase during surgery. If surgery is planned, Ritalin should not be taken on the day of surgery.
Use with centrally acting alpha-2 agonists (e.g. clonidine): Serious adverse events including sudden death, have been reported in concomitant use with clonidine, although no causality for the combination has been established.
Use with dopaminergic drugs: As an inhibitor of dopamine reuptake, Ritalin may be associated with pharmacodynamic interactions when co-administered with direct and indirect dopamine agonists (including DOPA and tricyclic antidepressants) as well as dopamine antagonists (antipsychotics, e.g. haloperidol). The co-administration of Ritalin with antipsychotics is not recommended because of the counteracting mechanism of action.
Use with serotonergic drugs: The concomitant use of methylphenidate and serotonergic drugs is not recommended as this may lead to the development of serotonin syndrome (see PRECAUTIONS). Methylphenidate has been shown to increase extracellular serotonin and norepinephrine and appears to have weak potency in binding serotonin transporter.
Pharmacokinetic interactions: Ritalin is not metabolized by cytochrome P450 to a clinically relevant extent. Inducers or inhibitors of cytochrome P450 are not expected to have any relevant impact on Ritalin pharmacokinetics. Conversely, the d- and l- enantiomers of methylphenidate in Ritalin did not relevantly inhibit cytochrome P450 1A2, 2C8, 2C9, 2C19, 2D6, 2E1 or 3A.
Ritalin co-administration did not increase plasma concentrations of the CYP2D6 substrate desipramine.
Case reports suggested a potential interaction of Ritalin with coumarin anticoagulants, some anticonvulsants (e.g. phenobarbital, phenytoin, and primidone), phenylbutazone, and tricyclic antidepressants but pharmacokinetic interactions were not confirmed when explored at larger sample sizes. The dosage of these drugs might have to be reduced.
An interaction with the anticoagulant ethylbiscoumacetate in 4 subjects was not confirmed in a subsequent study with a larger sample size (n=12).
Other specific drug-drug interaction studies with Ritalin have not been performed in vivo.
Drug/Laboratory test: Methylphenidate may induce false positive laboratory tests for amphetamines, particularly with immunoassays screen test.
Instructions for Use and Handling: Not applicable.
Incompatibilities: Not applicable.
Do not store above 30°C.
Store in the original package in order to protect from moisture.
N06BA04 - methylphenidate ; Belongs to the class of centrally-acting sympathomimetics. Used as CNS stimulant.
Tab 10 mg (immediate-release, divisible, white, round, flat, slightly bevelled edges imprinted with 'CG' on one side and 'A/B' with score on the other side) x 30's, 100's, 200's.