This drug will need to be taken at a different dosage for each patient. Follow the directions on the label or your doctor’s advice. The dosages that are shown below are only averages for this medicine. Should your dosage differ, only change it if your doctor specifically instructs you to.

The amount of medication you take depends on its strength. How many doses you take daily, how long you can wait between doses, and how long you take the drug are all influenced by the medical condition you are taking it for.

Concerning attention deficit hyperactivity disorder, or ADHD:

Concerning chewable tablets or solutions that have short half-lives, oral dosage formulations:

Adults:30 to 45 minutes before meals, take two or three doses daily. The usual dose is twenty to thirty milligrams (mg) per day. Your doctor may need to adjust your dosage. However, the daily dosage is usually limited to 60 milligrams.

Children six years of age and older: 5 mg twice daily, initially taken with lunch and breakfast. Your doctor may need to adjust your dosage. However, the daily dosage is normally limited to 60 milligrams.

Children under six: The dosage and usage must be determined by the physician.

Methylphenidate is a ligand-channel blocker and NDRI with a 2-3 fold preference for the dopamine transporter (DAT) over the norepinephrine transporter (NET), in contrast to cocaine, which functions as a local anesthetic and SNDRI. Contrary to several urban legends that imply otherwise, this is true. Cocaine is also more potent in serotonin transporters (SERTs) than it is in NDRI sites.[126][127]

Since methylphenidate contains two chiral centers, the molecule may exist in four different isomers. One pair of three isomers and one pair of erythro may be distinguished from one another; d-three-methylphenidate is the primary isomer that exhibits the desired pharmacological effects.[103][128] The property of being pressor amines is not shared by the erythro and three diastereomers. The drug was first sold in a 4:1 combination of erythro and three diastereomers; a later version only contained the three diastereomers. (±)-threo-methylphenidate, a threo derivative free of erythro diastereomers, is referred to as “TMP.” Since the three isomers are energetically favored, any undesired erythro isomers can be easily epimerized. The drug made entirely of dextrorotatory methylphenidate is more commonly known as dexmethylphenidate, d-MPH, or d-three-methylphenidate, while it is also occasionally referred to as d-TMP. Enantiomerically pure (2R,2’R)-(+)-three-methylphenidate