Amphetamines

Summary

Amphetamines are a class of mental health drugs that include all drugs ending in -amphetamine, like methamphetamine and dextroamphetamine. The exception to this rule is methylphenidate, which is an amphetamine-like drug that works similarly, but has a lower abuse potential. Amphetamines are CNS stimulants clinically used to treat ADHD and narcolepsy. Amphetamines can cause insomnia, so be sure to give the last dose before 6:00 pm to avoid interfering with nighttime sleep. Amphetamines can also cause hypertension and tachycardia, so the patient’s vital signs should be monitored closely. Other side effects of amphetamines include appetite suppression, leading to weight loss and growth suppression. As the nurse, be sure to closely monitor the patient’s height and weight, especially in children. And lastly, keep in mind that amphetamines can cause tolerance and dependence, leading to a high abuse potential.

Key Points

• Key Drugs
  • End in “-amphetamine”
    • Amphetamine
    • Dextroamphetamine
    • Methamphetamine
  • Methylphenidate (Ritalin, Concerta)
    • Is an amphetamine-like drug, meaning it acts in a similar mechanism but has a lower potential for abuse and tolerance than amphetamines
  • Mechanism
    • CNS Stimulant
      • Increases neurotransmitters dopamine and norepinephrine in the brain by inhibiting their reuptake
  • Clinical Use
    • Attention Deficit Hyperactivity Disorder (ADHD)
      • First line agent for treating ADHD
      • Increases attention span, decreases distractibility
    • Narcolepsy
      • Corrects abnormal sleep patterns
  • Side Effects and Adverse Reactions
    • Side effects may be more severe if taken with other stimulants like caffeine
    • Hypertension
      • Related to stimulant effect of increasing norepinephrine and dopamine signalling
      • Closely monitor patient’s blood pressure
      • Use with caution in patients with hypertension
      • Taking with MAOIs can result in a hypertensive crisis
    • Tachycardia
      • Increased HR is a stimulant effect
      • Dysrhythmias and angina may be seen
    • Insomnia
      • Related to stimulant (amphetamine-like) effects
      • Administer the last dose before 6:00 pm to avoid interference with sleep
    • Decreased appetite & weight loss, growth suppression
      • Closely monitor height and weight, especially in children
      • Methylphenidate is usually given 2-3 times a day before meals, but timing may be adjusted after consulting with provider if the child isn’t eating enough
    • Abuse potential
      • Tolerance / dependence