Nursing care
Non-stimulant ADHD medicines: atomoxetine, guanfacine and clonidine
Written and reviewed by Dana Whitfield, RN, MSN · 4 min read · Updated October 2026
Short answer
Non-stimulant ADHD medicines include atomoxetine, a norepinephrine reuptake inhibitor, and the alpha-2 agonists guanfacine and clonidine. Atomoxetine carries a boxed warning about suicidal thinking in children and teens and can affect the liver. Guanfacine and clonidine lower blood pressure and heart rate and can cause rebound hypertension if stopped suddenly. Benefits build over weeks.
Set expectations: these medicines work more slowly
Parents who have seen stimulants work on the first day may expect the same here. Atomoxetine is usually started low and increased over weeks, and full benefit may take around a month. Guanfacine and clonidine are also adjusted gradually. Teaching about this slower onset prevents families from stopping a medicine early because it seems not to be working.
Non-stimulants are not controlled substances in the way stimulants are, which can matter for families concerned about misuse or for children who could not tolerate a stimulant. That does not make them risk-free. Each needs a monitoring plan for mood, cardiovascular signs and growth, agreed with the prescriber before the first dose.
Before starting, the prescriber reviews heart history and baseline vital signs, and the nurse records blood pressure, pulse, height and weight so later changes can be compared. Ask about fainting, palpitations or chest pain with exercise, and about any family history of sudden cardiac problems, and pass concerns to the prescriber.
Watch mood closely with atomoxetine
Atomoxetine carries a boxed warning that children and teenagers taking it are more likely to have suicidal thoughts. Risk is highest when treatment starts or the dose changes. Teach caregivers to watch for new or worsening depression, hopelessness, agitation, irritability, withdrawal or talk of self-harm, and to contact the prescriber promptly if they appear.
Atomoxetine can also cause liver injury. Dark urine, yellowing of the skin or eyes, or upper abdominal pain need prompt reporting. Other effects include raised heart rate and blood pressure, dizziness, reduced appetite and slowed growth, so height and weight are tracked. Chest pain, palpitations or a prolonged painful erection need urgent attention.
Prevent rebound hypertension with guanfacine and clonidine
Guanfacine and clonidine act centrally to reduce sympathetic outflow, so expected effects include drowsiness, dizziness, lower blood pressure and slower heart rate. Teach the child to rise slowly, keep well hydrated and avoid overheating, because dehydration and heat increase the risk of fainting. Report fainting or a markedly slow pulse.
Stopping either drug suddenly can cause a rapid rise in blood pressure with nervousness, headache and a fast heartbeat. Withdrawal is planned by the prescriber as a gradual reduction. Missed doses over a weekend, a lost prescription or vomiting illness can all produce unplanned stopping, so families need a refill plan and to know who to call.
School staff should know the child takes one of these medicines, because drowsiness can affect learning and a hot sports day can increase the risk of dizziness or fainting.
Teach safe administration and interactions
Extended-release guanfacine tablets are swallowed whole, not crushed or chewed, and should not be taken with a high-fat meal. Follow the pharmacist's instructions for each clonidine formulation. Alcohol and other sedating medicines add to drowsiness, which matters for older adolescents who drive.
Atomoxetine must not be combined with monoamine oxidase inhibitors, so every new prescription, including antidepressants, should be checked against it. Atomoxetine is avoided in narrow-angle glaucoma, pheochromocytoma and serious heart conditions. Ask families to keep one medication list and share it with school nurses and any prescriber.
Work a hypothetical parent phone call
Imagine a hypothetical parent who calls to say their 10-year-old ran out of guanfacine three days ago and now has a headache and seems jittery. Options include advising the parent to restart the usual dose when the pharmacy reopens, reassuring them that the symptoms reflect ADHD returning, or arranging prompt assessment including blood pressure and contacting the prescriber. The last option is strongest because the pattern suggests rebound hypertension.
Restarting without advice may not be safe after a gap, and attributing symptoms to ADHD misses a cardiovascular effect. In real practice the prescriber decides how to resume or taper, and the nurse checks blood pressure and heart rate and reinforces refill planning to prevent recurrence.
Sources and further reading
MedlinePlus: Atomoxetine. Mechanism, boxed suicidality warning, liver injury signs, heart rate and blood pressure, growth, priapism, MAOI interaction and gradual onset.
MedlinePlus: Guanfacine. Extended-release use in ADHD, rebound blood pressure on stopping, orthostatic dizziness, dehydration and heat, whole tablets and high-fat meals.
MedlinePlus: Clonidine. ADHD use in children, abrupt-stop rebound hypertension, drowsiness, rising slowly and hydration.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our pediatrics practice questions are the closest set to what this page covers.
Common questions
How quickly does atomoxetine work?
It is started at a low dose and increased gradually, and full benefit may take about a month. Families should not judge it by the first few days.
What should parents watch for after starting atomoxetine?
New or worse low mood, agitation, hopelessness or self-harm talk, especially after starting or a dose change. Also dark urine or yellowing of skin or eyes.
Why must guanfacine or clonidine not be stopped suddenly?
Abrupt stopping can cause rebound high blood pressure with headache, nervousness and a fast heartbeat. The prescriber plans any reduction gradually.