Dexamfetamine

Also called dexamphetamine

Dexamfetamine is used to treat narcolepsy and attention deficit hyperactivity disorder (ADHD). Find out how to take it safely and possible side effects.

What is dexamfetamine?

Dexamfetamine is used to treat narcolepsy, a sleep disorder that causes you to feel excessively tired during the daytime but have disturbed sleep during the night. Dexamfetamine works by stimulating the central nervous system to increase your alertness and reduce excessive sleepiness during the day.

Dexamfetamine is also used to treat attention deficit hyperactivity disorder (ADHD), for people who do not find methylphenidate helpful. Dexamfetamine helps with concentration, impulsion control, and calming. It is a stimulant that works by increasing the amount of dopamine, a chemical in the brain.

Dose

In Aotearoa New Zealand dexamfetamine is available as tablets (5mg). 

  • The dose of dexamfetamine will be different for different people, depending on your age and your response to the medication.
  • Your doctor will start you on a low dose and increase it gradually over a few weeks. This allows your body to get used to the medicine and reduces side effects. 
  • Always take dexamfetamine exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much dexamfetamine to take, how often to take it and any special instructions.

How to take dexamfetamine?

  • Dexamfetamine is usually taken 1 to 3 times a day. Take your first dose when you wake up in the morning. If more doses are prescribed, take them by early afternoon. Taking this medication late in the day may cause trouble sleeping (insomnia). 
  • Swallow your tablets with a glass of water. You can take dexamfetamine with or without food, as directed by your doctor.
  • If you forget to take your dose, take it as soon as you remember. But if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.

Things to consider when taking dexamfetamine

  • Dexamfetamine and alcohol or marijuana: If you are taking dexamfetamine don't drink excessive amounts of alcohol, use marijuana or take party pills. Alcohol, marijuana and party pills can increase some of the effects of dexamfetamine and increase side effects. As well as this, drinking alcohol, smoking marijuana and taking party pills can often make your symptoms worse.
  • Dexamfetamine and other medicines or supplements: Dexamfetamine can interact with some medications, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting dexamfetamine and before starting any new products.
  • Dexamfetamine may affect your ability to drive: Dexamfetamine can affect your concentration (how you focus or pay attention). It can slow your reaction times and cause sleepiness, blurred vision, dizziness, slowed down movements and fainting, or make you feel anxious or jittery. Do not drive if you experience any of these. If you are a driver, talk to your doctor about your concerns.

Possible side effects 

Like all medicines, dexamfetamine can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Difficulty falling asleep 
  • Sleep problems are common when taking dexamfetamine.
  • Take your first dose when you wake up in the morning. If more doses are prescribed, take them by early afternoon.
  • Anxiety
  • Nervousness
  • irritability 
  • Changes in mood


  • These are common when you first start dexamfetamine.
  • Tell your doctor.
  • Headache
  • Lower appetite
  • These are common when you take dexamfetamine.
  • Tell your doctor if they bother you.
  • Chest pain
  • Unexplained fainting
  • Numbness or tingling in your hand or feet
  • These are rare but serious side effects.
  • Tell your doctor immediately or ring Healthline 0800 611 116
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.

References

  1. Dexamfetamine sulfate  New Zealand Formulary
  2. Guidance for the use of stimulant medications in adults RANZCP, 2015
Credits: Health Navigator Pharmacists. Reviewed By: Maya Patel, MPharm PGDipClinPharm, Auckland Last reviewed: 17 May 2022