Methylphenidate is FDA-approved for treating attention deficit hyperactivity disorder (ADHD) in children and adults and as a second-line treatment for narcolepsy in adults. Buy Ritalin Methylphenidate online in Australia
Children diagnosed with ADHD should be at least six years of age or older before being started on this medication. The treatment of both ADHD and narcolepsy have significantly better outcomes when used concurrently with nonpharmacologic therapies (i.e., social skills training in ADHD or sleep hygiene measures in narcolepsy).
Off-label uses of methylphenidate include treatment for fatigue in patients with cancer, refractory depression in the geriatric population, apathy in Alzheimer disease, and enhancing cognitive performance (e.g., memory). Since it can be abused as a cognitive enhancer, it is a federally controlled Schedule II substance. The efficacy of methylphenidate for its off-label uses varies from limited to moderate. Most of these relatively newer uses are still being studied and implemented into clinical practice. Buy Ritalin Methylphenidate online in Australia
Mechanism of Action
Methylphenidate blocks the reuptake of two neurotransmitters, norepinephrine (NE) and dopamine, in presynaptic neurons. More specifically, it inhibits the transporters of these neurotransmitters, increasing the concentration of dopamine and NE in the synaptic cleft. This creates its classic stimulant effect within the central nervous system (CNS), mainly in the prefrontal cortex. It chemically derives from phenethylamine and benzylpiperazine. It undergoes metabolism by the liver to ritalinic acid through a process called de-esterification via carboxylesterase CES1A1. Compared to other medications (i.e., amphetamines) that are phenethylamine derivatives, methylphenidate appears to increase the firing rate of neurons. It is also a weak agonist at the 5HT1A receptor, which is an additional mechanism that contributes to the increased levels of dopamine. Buy Ritalin Methylphenidate online in Australia
With the increase in dopamine levels, methylphenidate can provide neuroprotection in certain conditions like Parkinson disease, which involves loss of dopaminergic neurons and methamphetamine abuse. This effect occurs not only through its direct inhibition of the dopamine transporter but also via indirect regulation of the vesicular monoamine transporter 2. The combined interactions methylphenidate has on both of these transporters reduce the amount of dopamine that accumulates within the cytoplasm in patients with these conditions, thereby preventing the formation of reactive oxygen species that would otherwise be dangerously toxic to the brain. Buy Ritalin Methylphenidate online in Australia
The therapeutic dosages for ADHD or narcolepsy that physicians prescribe are not harmful enough to activate the reward system within the CNS, known as the nucleus accumbens. However, excessively higher dosages taken by those who intentionally abuse the drug lead to an overexpression of deltaFosB, a transcriptional activator, in specific neurons within the striatum. This accumulation of deltaFosB in the nucleus accumbens activates a series of signaling cascades that further triggers the addiction.
- Absorption: Slow but extensive; relative bioavailability for extended-release tablets 105% in children and 101% in adults (verses immediate-release tablets); the absolute oral bioavailability for extended-release capsules in children was 22% and 5% for d-methylphenidate and l-methylphenidate, respectively.
- Time of peak plasma concentration: 1.9 hours for immediate-release tablets and 4.7 hours for extended-release tablets
- Food effects: Increase total exposure and peak plasma concentration; reduce the time for peak plasma concentration for extended-release tablets.
- Alcohol effect: 98% of the drug from extended-release 40 mg capsule dosage form was released in an alcohol concentration of 40% in an in-vitro study.
- Distribution: Volume of distribution was 2.65 and 1.80 L/kg for d- methylphenidate and l- methylphenidate, respectively.
- Plasma Protein Binding: 10% to 33%
- Metabolism: It is primarily metabolized by de-esterification to ritalinic acid, which is pharmacologically inactive.
- Excretion: A majority of the drug (78% to 97%) is excreted in the urine, while small amounts are excreted in feces. Buy Ritalin Methylphenidate online in Australia
For medical purposes, methylphenidate is mainly given orally or, less commonly, as a transdermal patch. Multiple oral formulations are available that categorize according to how quickly the drug is released: immediate (IR), extended (XR or ER), and sustained. Two of the more unique formulations of methylphenidate are its ER sphenoidal oral drug absorption system that has a bimodal release and the osmotic (controlled) release delivery system. There are chewable tablets (either IR or ER) for children and an IR solution. Doses should not exceed 72 mg, the maximum dose of the ER tablet. If using the transdermal patch, the patient must be aware of placing the patch on the opposite hip each time to achieve its full effect. Those who misuse methylphenidate for recreational purposes prefer to use the intravenous (IV) or the intranasal route. Assess the risk of abuse before prescribing methylphenidate in any form. Buy Ritalin Methylphenidate online in Australia
Available Dosage Forms and Strengths
- Attention deficit disorder (ADD) in adults and pediatric patients (6 years and older) and for narcolepsy
- Chewable tablets: 2.5 mg, 5 mg, and 10 mg
- Immediate-release tablets: 5 mg, 10 mg, and 20 mg
- Attention deficit hyperactivity disorder (ADHD) in adults and pediatric patients (6 years and older) and for narcolepsy
- Immediate-release tablets: 5 mg, 10 mg, and 20 mg
- Extended-release tablets: 10 mg, 20 mg, 18 mg, 27 mg, 36mg, 54 mg, and 72 mg
- Extended-release tablets (24 hours): 18 mg, 27 mg, 36mg, and 54 mg
- Extended-release capsules: 10 mg, 20 mg, 30 mg, and 40 mg
- Extended-release capsules CD: 10 mg, 20 mg, 30 mg, 40 mg, 50 mg, and 60 mg
- Solution: 5 mg/ 5 ml and 10 mg / 5 ml in 500 ml bottle
- ADHD in adults and pediatric patients (6 years and older) as well as for narcolepsy
- Attention deficit hyperactivity disorder (ADHD) in pediatric patients (age 6 to 17 years)
- Orally disintegrating tablets: 8.6 mg, 13.7 mg, and 25.9 mg
- Patch: 10 mg, 15 mg, 20 mg, and 30 mg nominal dose over 9 hours. Buy Ritalin Methylphenidate online in Australia
Specific Patients Population
- Patient with Hepatic Impairment: There is no dose adjustment guidance in the manufacturer label for patients with hepatic impairment.
- Patient with Renal Impairment: There is no dose adjustment guidance in the manufacturer label for patients with renal impairment. However, most of the drug and its metabolites are excreted in the urine.
- Pregnant Women: It is considered as pregnancy category C medicine. Many researchers studied methylphenidate during pregnancy to treat ADHD and narcolepsy, However, data is conflicting so use the medication with caution.
- Breastfeeding Women: It is recommended to monitor and keep relative infant dose below 10% while using methylphenidate therapy in nursing mothers as the drug is present in breast milk.
- Pediatric Patients: There are multiple dosage forms and strengths available for pediatric patients ages ranging from 6 years to 17 years.
- Geriatric Patients: There is no specific dose adjustment guidance available. Buy Ritalin Methylphenidate online in Australia