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Monographs of Topical Drugs that Have Caused Contact Allergy/Allergic Contact Dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Methylphenidate is a synthetic central nervous system stimulant. It appears to activate the brain stem arousal system and cortex to produce its stimulant effect and, in some clinical settings, may improve cognitive function. Methylphenidate is indicated for the treatment of attention deficit hyperactivity disorder (ADHD) in patients 6 years of age and older and for the treatment of narcolepsy. It is available in a transdermal therapeutic system (1). In pharmaceutical products, both methylphenidate and methylphenidate hydrochloride (CAS number 298-59-9, EC number 206-065-3, molecular formula C14H20ClNO2) may be employed (1).
Late Effects of Treatment for Childhood Brain and Spinal Tumors
Published in David A. Walker, Giorgio Perilongo, Roger E. Taylor, Ian F. Pollack, Brain and Spinal Tumors of Childhood, 2020
Ralph Salloum, Katherine Baum, Melissa Gerstle, Helen Spoudeas, Susan R. Rose
Research has demonstrated efficacy of psychostimulants for improving attention deficits in children with brain tumors. Methylphenidate significantly improved sustained attention in a randomized, double-blind study compared to placebo.183 Improvements in attention, social behaviors, and academic competence were also reported in a randomized, double-blind, placebo-controlled study over a 3-week period.184 Treatment gains for methylphenidate have been found to be maintained for over a year.185 Other than psychostimulants, there has been little investigation of other medications for neurocognitive late effects. In a pilot study of donepezil, an acetylcholinesterase inhibitor, pediatric brain tumor survivors showed improvements in executive functioning, on both direct testing and proxy report.186
Clinical Psychopharmacology of Amphetamine and Related Compounds
Published in John Caldwell, S. Joseph Mulé, Amphetamines and Related Stimulants: Chemical, Biological, Clinical, and Sociological Aspects, 2019
There are a number of adverse effects, the most important of which is impairment of growth, which has been reported to occur in up to three quarters of the children treated with amphetamine.93 Whether or not such effects on growth are related in any way to the action of amphetamine on GH remains to be determined. Levoamphetamine is as effective as dextroamphetamine but is just as likely to stunt growth.94 Among other frequently reported effects are insomnia and tachycardia, and a few cases of amphetamine psychosis have occurred. Methylphenidate is less likely than dextroamphetamine to cause such unwanted effects and is therefore to be preferred.
Medical students and stimulants; they have enough knowledge but they still use non prescribed stimulants
Published in Journal of Substance Use, 2022
Afsaneh Rezaei Kalat, Atiyeh Taghavi, Emran Askari, Seyyed Mostafa Parizadeh, Ali Jafarzadeh Esfehani, Zahra Rajaei, Reza Jafarzadeh Esfehani, Ali Talaei
Stimulant drugs are known for their role in the management of psychiatric disorders, especially attention deficit hyperactivity disorder (ADHD). Stimulants, including methylphenidate-based agents, are considered the first-line treatment for ADHD in children and adolescents (Faraone, 2018). Methylphenidate can improve attention primarily through increasing dopamine activity in the brain, especially in the cortex and striatum (Faraone, 2018). Despite the promising role of this drug in managing psychiatric disorders, the potential non-prescribed use or dependency related to methylphenidate has become a great concern (Faraone, 2018; Kollins et al., 2001). This concern is highlighted mainly in the youth, and especially students (Poulin, 2007). Although some countries use community guidelines to limit non-prescribed use of stimulants, there is still a growing concern regarding the use of such drugs by the students (Fond et al., 2016). A recent systematic review demonstrated that 5% to 35% of college students use non-prescribed stimulants within a year (Willens et al., 2008). While there could be many reasons behind the non-prescribed use of stimulants by students, the critical role of social media and friends as the primary source of providers has been previously highlighted in the literature (Emanuel et al., 2013; Habibzadeh et al., 2011).
Drug induced stuttering: pharmacovigilance data
Published in Expert Opinion on Drug Safety, 2021
Thierry Trenque, Aurore Morel, Agathe Trenque, Brahim Azzouz
The greatest disproportionality was observed for methylphenidate. Methylphenidate is used to treat attention deficit and hyperactivity disorder (ADHD). As is the case for stuttering, the exact pathophysiological mechanisms of ADHD remain to be elucidated. Data regarding the existence of a link between stuttering and methylphenidate are conflicting, with some publications reporting the use of methylphenidate to treat stutter [5,15], and other reporting the onset of stuttering during treatment with methylphenidate [6,16]. Several studies have reported a dopamine/norepinephrine deficit and disturbances of the dopamine pathway, with a reduction in dopaminergic receptors [17]. Methylphenidate has amphetamine-like properties and increases dopamine-mediated neurotransmission by blocking presynaptic uptake of dopamine and noradrenaline. This in turn increases the synaptic extracellular release of these neurotransmitters, resulting in an increase in the synaptic concentration of dopamine [18]. The increase in dopaminergic system activity during methylphenidate therapy in a patient with ADHD could explain the onset of stuttering during treatment. Our study, including reports submitted over a longer period, supports previous findings regarding stuttering and methylphenidate [19].
Is genetic variability in carboxylesterase-1 and carboxylesterase-2 drug metabolism an important component of personalized medicine?
Published in Xenobiotica, 2020
S. Casey Laizure, Robert B Parker
Methylphenidate is a central nervous system stimulant used to treat attention deficit disorder. The active drug is methylphenidate, which is metabolized to the inactive ritalinic acid by CES1-catalyzed hydrolysis. A reduction in CES1 enzyme activity in carriers of the c.428GA allele would be expected to reduce the clearance of methylphenidate altering its disposition. In a study conducted in 22 Danish, Caucasian normal volunteers taking a single 10 mg dose of methylphenidate, carriers of the c.428GA allele (n = 6) had a dex-methylphenidate AUC and Cmax of 53.3 ng/mlxh and 9.1 ng/mL compared to 21.4 ng/mlxh and 5.0 ng/mL in 428GG carriers (n = 16), respectively. This represents a 150% increase in the AUC and 82% increase in the Cmax in carriers of the variant allele. The large increase in the Cmax suggests a decrease in first-pass metabolism of methylphenidate increasing its bioavailability. This would be consistent with the finding in children who were carriers of the 428GA allele showing a lower dose of methylphenidate was required to achieve a therapeutic response (0.410 mg/kg versus 0.572 mg/kg, p < .022) (Nemoda et al., 2009).