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Dexmethylphenidate: 7 things you should know

Medically reviewed by Carmen Fookes, BPharm. Last updated on Jun 10, 2020.

1. How it works

  • Dexmethylphenidate is a component of racemic methylphenidate (methylphenidate contains two isomers: d-threo-methylphenidate [which is dexmethylphenidate] and l-threo-methylphenidate). The d-isomer is much more potent than the l-isomer.
  • Experts aren't exactly sure how dexmethylphenidate works in Attention Deficit Hyperactivity Disorder (ADHD) but think it affects the reuptake of both dopamine and norepinephrine, two neurotransmitters.
  • Dexmethylphenidate is called a central nervous system (CNS) stimulant.

2. Upsides

  • Used in the treatment of ADHD in adults and children over the age of six.
  • Dexmethylphenidate should be used in addition to other treatment modalities such as psychotherapy, education, and social integration advice.
  • Dexmethylphenidate is available as immediate-release tablets and extended-release capsules.
  • Generic dexmethylphenidate is available.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • A headache, abdominal pain, decreased appetite, nausea, nervousness, and fever. May also cause muscle twitching, sleeplessness, increased blood pressure, and a fast heartbeat.
  • Dexmethylphenidate is associated with abuse and dependence. The risk of dependence is greater with the extended-release capsules and in people with a history of drug dependence and alcoholism. Psychotic episodes have also been reported, particularly with overuse.
  • May impair judgment or reaction skills. Exercise caution before driving or operating machinery until the full effects of dexmethylphenidate are known.
  • May aggravate preexisting symptoms of anxiety, tension, and agitation. May precipitate the emergence of psychotic thoughts such as hallucinations, delusions or mania in people without a prior history of such thoughts. Discontinuation of treatment may be appropriate.
  • May not be suitable for people with certain heart conditions, glaucoma, a history of tics or a family history of Tourette's syndrome, with certain psychiatric disorders, or with a history of alcohol overuse or drug dependence. Has been associated with an increased risk of sudden death in people with structural heart abnormalities or other serious heart problems; may also increase the risk of a stroke or heart attack in adults.
  • May increase the risk of seizures and peripheral circulatory problems and cause visual problems.
  • Reports indicate some temporary slowing of growth may occur when long-term dexmethylphenidate is given to children. Doctors should monitor height and weight and consider treatment interruption if growth suppression is suspected.
  • Rare cases of priapism (painful erections lasting more than 6 hours) have been reported.
  • May interact with some other medications including monoamine oxidase inhibitors (MAO inhibitors) (do not use within 14 days of discontinuation of an MAO inhibitor), halogenated anesthetics (do not take dexmethylphenidate on the day of surgery), coumarin anticoagulants, anticonvulsants, antidepressants and drugs used to treat high blood pressure.
  • Alcohol may contribute to the side effects of dexmethylphenidate and should be avoided.
  • Classified as a Schedule II controlled substance, meaning that dexmethylphenidate has a high potential for abuse. Keep personal supplies of dexmethylphenidate in a safe place, out of view of potential drug seekers.
  • Should not be used in children under the age of six.

Notes: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. For a complete list of all side effects, click here.

4. Bottom Line

Dexmethylphenidate improves symptoms of ADHD but carries with it a risk of dependence. It is twice as potent as methylphenidate.

5. Tips

  • Immediate-release dexmethylphenidate tablets are usually taken twice daily, at least four hours apart. Ensure that the last dose is not taken any later than 6pm. Extended-release capsules are taken once daily, in the morning.
  • May be taken with or without food.
  • Take exactly as directed by your doctor and never increase the dosage without his or her advice.
  • Swallow extended-release capsules whole with a glass of water; do not chew, divide or crush. For people who have difficulty swallowing, the capsule may be opened and the contents mixed with applesauce then swallowed immediately.
  • Do not drive or operate machinery if dexmethylphenidate impairs your judgment or reaction times.
  • Seek medical advice if any new numbness, pain, skin color change or sensitivity, or unexplained wounds occur in fingers or toes.
  • Avoid alcohol because it may potentiate the side effects of dexmethylphenidate.
  • Seek urgent medical attention if you develop any chest pain, shortness of breath or if fainting occurs while taking dexmethylphenidate. Call your doctor if you have any new or worsening mental symptoms such as hallucinations, delusions, or hearing voices. Seek medical advice if symptoms persist or worsen despite treatment.
  • Seek medical advice if your fingers or toes become numb, painful, the skin changes color or breaks down. Seek emergency attention if painful, prolonged erections occur.

6. Response and Effectiveness

  • Initial peak concentrations of dexmethylphenidate are reached within an hour to an hour and a half.
  • Some symptom relief may be noticed after one to two hours; however, it may take up to two weeks before the full effects of dexmethylphenidate are seen.
  • Extended-release capsules have a two-phase release system. Half the dose is provided in immediate-release beads and the other half as delayed-release beads. One single extended-release capsule provides the same amount of active ingredient as two immediate-release tablets given four hours apart.
  • Dexmethylphenidate is approximately twice as potent as methylphenidate.

7. Interactions

Medicines that interact with dexmethylphenidate may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with dexmethylphenidate. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with dexmethylphenidate include:

  • anticoagulants (blood thinners) such as apixaban, dabigatran, heparin, or warfarin
  • anticonvulsants, such as phenytoin, phenobarbital, or primidone
  • antidepressants, such as amitriptyline, amoxapine, citalopram, clomipramine, desipramine, doxepin, fluoxetine, fluvoxamine, imipramine, isocarboxazid, nortriptyline, paroxetine, phenelzine, protriptyline, sertraline, trimipramine, and venlafaxine. Do not use within 14 days of discontinuation of an MAO inhibitor
  • decongestants, such as phenylephrine or pseudoephedrine
  • high blood pressure medications, such as ACE Inhibitors, alpha blockers, ARBs, beta blockers, calcium channel blockers, or diuretics
  • others, such as halogenated anesthetics (do not take dexmethylphenidate on the day of surgery) or guanfacine.

Avoid drinking alcohol or taking illegal or recreational drugs while taking dexmethylphenidate. Antacids should not be taken with the extended-release form of dexmethylphenidate.

Note that this list is not all-inclusive and includes only common medications that may interact with dexmethylphenidate. You should refer to the prescribing information for dexmethylphenidate for a complete list of interactions.


Dexmethylphenidate. Revised 01/2020.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use dexmethylphenidate only for the indication prescribed.

Copyright 1996-2020 Revision date: June 10, 2020.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.