Several types of medication are used to treat ADHD.
Psychostimulants: Methylphenidate (Ritalin) and Similar Drugs
Psychostimulants are the primary drugs used to treat ADHD. Although these drugs stimulate the central nervous system, they have a calming effect on people with ADHD.
These drugs include:
- Methylphenidate (Ritalin, Concerta, Daytrana, Metadate, Methylin, Quillivant, generic)
- Dexmethylphenidate (Focalin, generic)
- Amphetamine-Dextroamphetamine (Adderall, generic)
- Dextroamphetamine (Dexedrine, Dextrostat, generic)
- Lisdexamfetamine (Vyvanse)
Methylphenidate and Dexmethylphenidate. Methylphenidate drugs (Ritalin, Concerta, Daytrana, Metadate, Methylin, Quillivant XR, and generic versions) are the most commonly used psychostimulants for treating ADHD in both children and adults. Dexmethylphenidate (Focalin, generic) is a similar drug. These drugs increase dopamine, a neurotransmitter important for cognitive functions such as attention and focus.
With the exception of Daytrana and Quillivant XR, all of these drugs are pills taken by mouth. Daytrana is a skin patch drug for ADHD. A patch is applied to the hip each day and delivers a 9-hour dose of methylphenidate. Quillivant is a liquid form of methylphenidate that is approved for patients age 6 and older who may have difficulty swallowing pills.
These drugs are available in short-acting and long-acting dosage forms. The short-acting forms need to be taken several times a day, including during school hours. As the drug wears off, a rebound effect can occur, and ADHD symptoms can intensify. For this reason, the long-acting dosage forms have become popular.
Amphetamine, Dextroamphetamine, and Lisdexamfetamine. Amphetamine-dextroamphetamine (Adderall, generic), dextroamphetamine (Dexedrine, Dextrostat, generic), and lisdexamfetamine (Vyvanse) work by blocking the reabsorption of the brain chemicals dopamine and norepinephrine.
Side Effects. Decreased appetite, stomach pain, headaches, and sleeplessness are the most common side effects of stimulant drugs. Tics or jerky movements develop in a small percentage of children, but this side effect usually goes away when the dosage is lowered.
Stimulant drugs may also:
- Worsen behavior and thought disturbance in patients with a pre-existing psychotic disorder. These drugs may also slightly increase the risk for auditory hallucinations, paranoia, and psychotic and manic behavior even in patients who do not have a history of psychiatric problems.
- Cause a mixed or manic episode in patients who have both ADHD and bipolar disorder.
- Increase aggressive behavior or hostility. Patients beginning stimulant drug treatment should be monitored for worsening of these behaviors.
- Reduce growth and weight gain in children. Children who take stimulant drugs should have their growth monitored. If they do not gain height or weight at a normal rate, they may need to stop taking the drug.
- In rare cases, methylphenidate drugs can cause painful and long-lasting erections (priapism) even in young children. Patients who experience erections lasting longer than 4 hours should seek immediate medical attention to prevent permanent damage to the penis.
Cardiovascular Risks. All ADHD stimulant drugs carry warnings that they should not be used by patients with structural heart problems or pre-existing heart conditions (high blood pressure, heart failure, heart rhythm disturbances, or congenital heart disease). These drugs have been associated with sudden death in children with heart problems. They have also been associated with sudden death, stroke, and heart attack in adults with a history of heart disease. According to recent large studies, these medications appear to be safe for children and adults who do not have underlying heart disease.
Symptoms of Overdose. Symptoms of overdose include changes in heart rhythm and rate, hypertension, confusion, breathing difficulties, sweating, vomiting, and muscle twitches. If they occur, parents should immediately call the doctor.
Concerns for Abuse. Stimulant drugs can be habit forming, but they are not considered especially addictive, particularly when they are taken as prescribed in the doses used for treating ADHD. The primary danger for drug abuse from stimulants appears to occur in young people without ADHD who purchase and use these drugs illegally. If a child abuses another drug (alcohol, prescription medication) along with the ADHD medication, the chance for serious side effects is increased.
Atomoxetine (Strattera) was the first non-stimulant approved for ADHD in children and the first treatment approved for adult ADHD. The drug works by increasing levels of both norepinephrine and dopamine, which are generally lower than normal in ADHD. The most common side effects are drowsiness, decreased appetite, and upset stomach.
A few cases of atomoxetine-associated liver injury have been reported, and the FDA warns that the drug should be discontinued at the first signs of jaundice (yellowing of skin and eyes) and liver problems. Long-term effects, such as any impact on growth, are still unknown. Although rare, atomoxetine poses an even greater risk than methylphenidate for severe, long-lasting erections (priapism).
Atomoxetine may cause suicidal thinking in children and adolescents, especially during the first few months of treatment. Parents should monitor children taking atomoxetine for any changes in mood or behavior, and immediately contact their doctor if changes occur.
Alpha-2 Agonists (Guanfacine and Clonidine)
Alpha-2 agonists stimulate the neurotransmitter norepinephrine, which appears to be important for concentration. They include guanfacine (Tenex, Intuniv, generic) and clonidine (Catapres, generic). These drugs may be prescribed in combination with a stimulant.
Alpha-2 agonists have a number of side effects. Sleepiness and dry mouth are the most common, followed by headache and fatigue. Because clonidine slows the heart down, it can have adverse effects in some children. Discontinuing the drug abruptly or missing doses can cause rapid heartbeats and other symptoms that may lead to severe problems. Doctors strongly recommend that no child be given clonidine without a preliminary examination for heart problems, and no child with existing heart, kidney, or circulatory problems should take it.
Antidepressants are not FDA-approved for ADHD treatment, but may be helpful in certain circumstances. Because antidepressants appear to work about as well as behavioral therapy, doctors recommend that patients first try psychotherapy before using antidepressants.
Bupropion (Wellbutrin, generic) and tricyclics are the types of antidepressants used for ADHD. Bupropion affects the reuptake of the serotonin, norepinephrine, and dopamine neurotransmitters. Side effects include restlessness, agitation, sleeplessness, headache, and stomach problems. Bupropion should not be used by patients who have a seizure disorder. Bupropion may also be associated with the development of suicidal thoughts and behavior, even in people who have no previous history of depression.
Tricyclics are an older type of antidepressant that can be beneficial but have many side effects. Imipramine (Tofranil, generic) and nortriptyline (Pamelor, generic) are the tricyclics most commonly prescribed for ADHD. A third tricyclic, desipramine (Norpramin, generic) should only be used if patients are not helped by other tricyclics. Desipramine has caused sudden death in some children and adolescents and is especially dangerous for patients with a family history of heart rhythm disturbances.
Tricyclic antidepressants can cause disturbances in heart rhythm. Children should have an electrocardiogram when they first begin to take this drug, and after any dose increase.