ADHD Medications and Side Effects

Medically Reviewed by Zilpah Sheikh, MD on December 19, 2023
10 min read

Medication may be an important part of your ADHD treatment plan. Doctors can choose from many types of drugs to control your symptoms. Whichever medication you and your doctor choose, they all work the same -- to increase levels of certain chemicals in your brain (called neurotransmitters). These chemicals help reduce symptoms (such as hyperactivity and impulsivity), increase attention span, and help you manage your emotions.

You and your doctor will work together to figure out which medication is right for you, along with the ideal dose (amount) and schedule (how often or when you need to take it). It may take some time to find the best combination.

Medications may not work for all ADHD symptoms or affect everyone the same way. A combination of medication, therapy, behavior changes, and skills training is often the most effective treatment. This is called multimodal treatment.

The medications most often used to treat ADHD include:

  • Stimulants. These medicines are called stimulants because they increase the brain chemicals dopamine and norepinephrine. These two chemicals have important effects on your ability to think and pay attention.
  • Non-stimulants. In cases where stimulants don’t work or cause unpleasant side effects, non-stimulants might help. These medicines take longer to start working than stimulants, but they may help improve your ability to focus, pay attention, and control your impulses. Sometimes, doctors may prescribe these along with a stimulant to improve how both work.
  • Antidepressants. These aren't approved by the U.S. FDA for ADHD treatment, but some people find they help control the symptoms of ADHD. So, your doctor may try these if you have side effects from stimulants. Also, people with ADHD often have depression, anxiety, or other mood disorders (such as bipolar disorder). If this is the case for you, your doctor may prescribe an antidepressant to control these other conditions along with a stimulant for ADHD.

Things to think about if you are considering starting medicine for ADHD

Medications can be the cornerstone of ADHD treatment, and they work well for many people. But they aren't the only option. Take your time to weigh your options. If you're not ready to try medicine, behavior therapy works well for many people. Behavior therapy will help you learn positive behaviors and reduce negative behaviors.

This group of drugs is the most commonly prescribed to treat ADHD. They have been used to treat ADHD in children for several decades. These drugs increase the levels of the neurotransmitters dopamine and norepinephrine in your brain, which may help you focus your thoughts and ignore distractions. The FDA has approved dozens of brand-name stimulants for ADHD. All of them contain versions of two different stimulant drugs called methylphenidate and amphetamine.

Doctors don't recommend stimulants for people with:

  • Heart defects or heart disease

  • High blood pressure

  • Hyperthyroidism

  • Glaucoma

  • High levels of anxiety

  • A history of drug abuse

There are two kinds of stimulants: short-acting (immediate-release) and intermediate or long-acting (extended-release).

Short-acting stimulants

These medicines usually begin working within 30-45 minutes of taking them and can last about 3-4 hours. You usually take them two to three times a day. 

Amphetamines may be a little stronger than methylphenidate, and their effects may last a little longer. However, in general, the two kinds of medicines are very similar.

Some examples of each kind of short-acting stimulant include:

  • Amphetamine: Adderall, Dexedrine, Evekeo, Zenzedi
  • Methylphenidate: Ritalin and Focalin

Intermediate and long-acting stimulants

Intermediate stimulants can last 6-8 hours, while long-acting stimulants can last 8-12 hours and sometimes up to 16 hours. You usually take them once a day. Long-lasting medicines are usually the best option because people with ADHD may have trouble remembering to take their medicine.

Some examples for each kind of intermediate and long-acting stimulant include:

  • Amphetamine: Adderall XR, Vyvanse, Dexedrine Spansule, Dynavel XR, Adzenys XR-ODTC
  • Methylphenidate: Concerta, Metadate CD, Ritalin-LA, Aptensio-XR, and Focalin XR

Side effects of stimulants

Common side effects of stimulants include: 

  • Loss of appetite
  • Upset stomach
  • Feeling restless or jittery
  • Racing heartbeat
  • Trouble sleeping
  • Irritability or mood swings
  • Headaches
  • Dizziness
  • Depression
  • Tics

Long-acting medicines may have greater effects on appetite and sleep than short and intermediate-acting stimulants. Stimulants may also raise your blood pressure and heart rate.

Other safety concerns with stimulants

Aside from their side effects, some experts have a few other concerns about stimulants, including:

  • The long-term effects on people whose brains are still developing. Researchers don't yet know if stimulants affect the long-term development of the brain in children and teenagers, so some experts are wary of using these drugs in younger people.
  • The risk of sudden death in people with heart conditions. The American Heart Association recommends that all people, including children, have their heart evaluated before starting stimulants. They recommend doctors ask about the patient's medical and family history, specifically about symptoms that could suggest a heart condition. Also, they recommend a physical exam to look for evidence of a heart condition, including an electrocardiogram (EKG) if the medical and family history or physical exam suggested a reason to suspect a heart condition. 
  • The increased risk for other psychiatric problems. Some people may have personality changes on stimulant medicines. For instance, stimulants may trigger or make worse symptoms of hostility, aggression, anxiety, depression, or paranoia. People who have a personal or family history of suicide, depression, or bipolar disorder may be at higher risk of this than other people and will likely be followed closely by their doctor while they're taking stimulants.
  • The potential for abuse. A growing problem in schools and colleges is that teens and college students may abuse stimulants when they study for exams or when they want to lose weight. Kids with prescriptions may share or sell their stimulant medicine to classmates. Make sure your child is taking their medicine and not sharing or selling it.

About 15%-30% of kids don't respond to stimulants and this is probably the case for adults, too. If stimulants don't work for you or you can't tolerate the side effects of stimulants, non-stimulants may be an option for you. Your doctor may also prescribe these to take with stimulants because they can boost the effects. Non-stimulants are not controlled substances, so there's less chance of abuse. These may also be a good option for you if you have had problems with drug abuse before.

Non-stimulant medications usually take a while to start working, so it could be several weeks before you feel the full effects. Also, they may not work as well as stimulants.

The U.S. FDA has approved four non-stimulants for the treatment of ADHD:

  • Atomoxetine (Strattera)
  • Clonidine (Kapvay)
  • Guanfacine (Intuniv)
  • Viloxazine (Qelbree)

Atomoxetine (Strattera) and viloxazine (Qelbree)

These two drugs belong to a class of antidepressants called selective norepinephrine reuptake inhibitors (SNRIs). These medications increase your brain's level of a neurotransmitter called norepinephrine. They may help improve your ability to concentrate and control your impulses, but they may not work as well for symptoms of hyperactivity. You may not feel the effects until you’ve been taking them regularly for about 3-4 weeks, but they generally work for 12-24 hours.

Because they are antidepressants, they may be a good option if you also have anxiety or depression. Atomoxetine is approved for kids aged 6-17, and it's also sometimes prescribed for adults. One benefit to these is that they don’t cause or worsen tics or other symptoms of Tourette’s syndrome.

Guanfacine (Intuniv) and clonidine (Kapvay) 

These two drugs belong to a class of high blood pressure drugs called alpha-2 adrenergic agonists. These were initially used “off-label” for ADHD for many years. Off-label is the term used when a doctor prescribes a medication for a condition for which it’s not received approval from the FDA for treatment. Drug makers eventually made extended-release versions, and the FDA approved them as a treatment for ADHD.

Because these drugs are meant to lower high blood pressure, they have a calming effect, which may help you with symptoms such as hyperactivity, your ability to control your impulses, and feelings of aggression. But they may not help as much in improving attention and focus.

Side effects of non-stimulants

Atomoxetine and viloxazine side effects in adults and kids include:

  • Stomach pain or upset stomach
  • Nausea or vomiting
  • Mood Swings
  • Headaches
  • Dizziness
  • Sleepiness

These may cause insomnia and appetite suppression, but it's less common than with stimulants. Adults may also have dry mouth, trouble peeing, and sexual side effects, such as erectile dysfunction. Atomoxetine may also cause high blood pressure, increased heart rate, and liver problems in some people.

Rarely, SNRIs may increase the risk of suicidal thoughts and actions in some people, especially kids and young adults who have bipolar disorder or depression.

Guanfacine and clonidine side effects include:

  • Nausea, stomach pain, or vomiting
  • Loss of appetite
  • Headaches
  • Dizziness
  • Sleepiness, fatigue
  • Dry mouth

Don't stop taking these suddenly because this can cause your blood pressure and heart rate to rise quickly.

Other than the two SNRIs already mentioned, the FDA has not approved any other types of antidepressants for ADHD treatment. However, some are used off-label for this purpose, especially for people who have ADHD as well as depression or anxiety. This may also be an option for you if stimulants don't work, if you can't tolerate stimulants, or if you have a history of drug abuse.

The most common antidepressant prescribed off-label for ADHD is bupropion (Wellbutrin). Bupropion belongs to a class of antidepressants known as norepinephrine and dopamine reuptake inhibitors (NDRIs). It works by increasing the neurotransmitters norepinephrine and dopamine in your brain, which can help you improve your ability to concentrate.

If other ADHD drugs haven’t worked out for you, your doctor may suggest a tricyclic antidepressant, such as imipramine (Tofranil) or nortriptyline (Pamelor/Aventyl). Tricyclics are an older class of antidepressants. They can have challenging side effects, so your doctor will usually only try these if you have no other options left to try.

Off-label antidepressant side effects

Bupropion side effects include:

  • Nausea, stomach pain, or constipation
  • Weight loss
  • Dry mouth or a sore throat
  • Headaches
  • Dizziness
  • Insomnia
  • Increased heart rate

Some people may have more challenging side effects, such as anxiety, ringing in the ears, and changes in vision or heart and lung function. Adults may also rarely have sexual side effects. Bupropion may also increase the risk of suicidal thoughts in people aged 18-24 years old.

Imipramine and nortriptyline side effects include:

  • Constipation
  • Increased appetite and weight gain
  • Dry mouth
  • Dizziness
  • Blurred vision
  • Confusion
  • Seizures
  • Increased heart rate 
  • Not being able to empty your bladder fully when you pee, peeing a little bit many times over the day, or feeling like you have to pee but not being able to
  • Increased sweating
  • Sexual dysfunction, including libido changes and impotence

Like all tricyclic antidepressants, both imipramine and nortriptyline can change your heart rhythm. Both may also increase the risk of suicidal thoughts in people aged 18-24 years old. Don't stop taking nortriptyline suddenly because you can have withdrawal symptoms, such as nausea, vomiting, anxiety, headaches, dizziness, and restlessness. If you want to stop taking it, your doctor will decrease your dose over time to wean you off safely.

New medicines are always in development, and governing agencies continue to approve new brand-name ADHD medications. Most of these are drugs that have been used in other conditions and have been tested and approved for use in ADHD. For instance, viloxazine (Qelbree) was approved by the U.S. FDA in 2021 for use in kids and teenagers with ADHD, but in Europe, it had been used since 1971 as an antidepressant. Also, generic versions of brand-name drugs become available over time. For instance, in 2023, the FDA approved generic versions of lisdexamfetamine dimesylate (Vyvanse), which is a brand-name stimulant medicine approved in 2007.

Experts generally consider these medicines safe when they are monitored properly by a professional. Serious problems are rare. Discuss the risks and benefits of these drugs with your doctor.

ADHD medicines: Controlled substances

The most common ADHD medicines are stimulants, and they have a high potential for misuse, abuse, and addiction. People who don’t have ADHD may misuse the medicines to feel more alert, curb their appetite to lose weight, or to feel “high.”

Some people may intensify the effects of the drug by taking higher doses or even crushing and injecting, smoking, or snorting them. This can cause serious side effects, including:

  • Dangerously high body temperature
  • Fast heartbeat
  • High blood pressure
  • Panic attacks
  • Paranoia
  • Psychosis
  • Violent behavior
  • Seizures

Because of the risk of misuse and abuse, the U.S. Drug Enforcement Administration (DEA) classifies stimulants as Schedule II Controlled Substances. This means that while there's a medical use for them, there's also a high potential for them to be abused. To help cut down on the misuse of these drugs, Schedule II Controlled medicines are harder to get because they can't be refilled. Your doctor must write a new prescription for the medicine each time.

As of May 2023, the FDA requires makers of stimulant drugs to put “boxed warnings” on the labels to warn people of the risk of abuse, misuse, addiction, and overdose. Boxed warnings, also called black box warnings, are the most serious warning given by the FDA for an approved medicine. These warnings let the public and health care providers know they may cause serious side effects, such as injury or death.

Up to 80% of people with ADHD also have another condition. Some disorders are more common in people with ADHD. These include:

  • Disruptive behavior disorders, such as oppositional defiant disorder or conduct disorder
  • Mood disorders, such as depression or bipolar disorder
  • Anxiety
  • Tourette's syndrome and other tic disorders
  • Learning disorders, including dyslexia
  • Sleep disorder
  • Substance abuse

If you have ADHD and another condition, you and your doctor may choose to treat your ADHD symptoms first. The medicine you use to treat your ADHD symptoms may improve your attention, which can improve the symptoms of your other condition.

But in some cases, your ADHD medicine may worsen your other condition. For example, some stimulant medications can make your anxiety symptoms worse. Your doctor may be able to combine treatments to help all your symptoms, although they may need to try different combinations to find what’s best for you.

ADHD medications work to increase the levels of neurotransmitters in your brain. These chemicals help reduce your symptoms including hyperactivity and impulsivity, increase your ability to pay attention, and manage your emotions. Here are some articles for further reading to understand your ADHD medication options: