Non-Stimulant ADHD Medications: When Your GP Might Suggest Them

Stimulant medications are the usual first-line treatment for adult ADHD in Australia, but they are not suitable for everyone. Depending on your medical history, stimulants may not be appropriate for you. If stimulants cause intolerable side effects, interact with other medications, or are not effective after a full trial, your GP has non-stimulant alternatives to consider. This guide covers the three non-stimulant medications available in Australia for ADHD: atomoxetine (Strattera), guanfacine (Intuniv), and clonidine, including how they work, PBS subsidy status, and what the treatment experience looks like.

When your GP might suggest a non-stimulant

The AADPA Australian ADHD Clinical Practice Guideline recommends stimulants (methylphenidate or dexamphetamine-based medications) as first-line treatment for ADHD in most adults. Non-stimulants are most often second-line, meaning your GP will usually consider them after stimulants have been tried.

Your GP might suggest a non-stimulant if:

Stimulants caused unacceptable side effects: persistent anxiety, severe insomnia, significant appetite loss, or cardiac concerns (raised blood pressure or heart rate) that did not resolve with dose adjustments.
You trialled both stimulant classes without adequate benefit: amphetamine-based (Vyvanse, dexamphetamine) and methylphenidate-based (Ritalin, Concerta) medications work through different pathways. If neither class worked, a non-stimulant offers a different mechanism.
You have a co-occurring condition that interacts with stimulants: severe anxiety disorders, tic disorders, active substance use disorder, or certain cardiac conditions may make stimulants a less suitable first choice.
You have a history of substance misuse: non-stimulants are unlikely to have abuse potential. Atomoxetine and guanfacine are not controlled substances.
You prefer a non-stimulant approach: patient preference is a valid clinical consideration, though your GP will explain the relative effectiveness differences.

Atomoxetine (Strattera): how it works and what to expect

Atomoxetine is a selective noradrenaline reuptake inhibitor (SNRI). It blocks the reuptake of noradrenaline at the presynaptic transporter, increasing noradrenaline and dopamine levels specifically in the prefrontal cortex. In plain terms: it boosts the brain chemicals involved in attention and executive function, but unlike stimulants, it does not affect the reward pathways associated with abuse potential.

Key facts about atomoxetine:

Onset: atomoxetine takes longer to work than stimulants. Initial effects appear within 1 to 2 weeks, clinically meaningful improvement takes 4 to 6 weeks, and full therapeutic benefit may take up to 12 weeks. This is a significant difference from stimulants, which work within an hour of the first dose.
Dosing: adults start at 40 mg daily for 1 to 2 weeks, then increase to a target of 80 mg daily. The maximum TGA-approved dose is 100 mg daily. Taken once daily (morning or evening) or split into two doses.
Duration: provides 24-hour coverage. Unlike stimulants, there is no wearing-off period or rebound effect.
Common side effects: nausea (especially in the first 2 weeks, reduced by taking with food), dry mouth, decreased appetite, insomnia or drowsiness, constipation, and dizziness. Nausea is the side effect most likely to cause people to stop treatment, but it usually settles.
Serious side effects to monitor: rare but documented. Liver injury (report unexplained nausea, dark urine, or jaundice immediately), increased suicidal thinking in young people (TGA black box warning for under-25s), and cardiovascular effects (blood pressure and heart rate monitoring required).
Metabolism note: about 7% of Caucasians are CYP2D6 poor metabolisers, meaning atomoxetine is processed more slowly. These patients need lower doses (40 mg maximum initially, up to 80 mg). Your GP can consider pharmacogenomic testing if response is unusual.

Guanfacine (Intuniv): how it works and what to expect

Guanfacine is a selective alpha-2A adrenergic receptor agonist. It activates alpha-2A receptors in the prefrontal cortex, which strengthens the neural connections involved in attention, working memory, and impulse control. In plain terms: it calms overactive signalling in the brain without the stimulating effect of amphetamines or methylphenidate.

Key facts about guanfacine:

Onset: effects begin within 1 to 2 weeks, with full benefit typically seen by week 4.
Dosing: the extended-release form (Intuniv) starts at 1 mg daily, titrated in 1 mg increments weekly. Target dose for adults is typically 1 to 4 mg daily, though some adults go up to 7 mg.
Administration: taken once daily, usually at bedtime to minimise daytime drowsiness. Swallowed whole (not crushed or chewed). Should not be taken with high-fat meals, which increase absorption unpredictably.
Common side effects: drowsiness and sedation (the most common, especially in the first 2 weeks), low blood pressure, dizziness, dry mouth, constipation, and fatigue. Sedation is often the limiting factor and the reason many adults struggle with guanfacine.
Stopping: guanfacine must not be stopped abruptly. Sudden discontinuation can cause rebound hypertension (a spike in blood pressure). Your GP will taper the dose gradually over 3 to 7 days.
Particular strengths: guanfacine is useful for ADHD patients with prominent hyperactivity, impulsivity, or co-occurring tic disorders. It is also sometimes added alongside a stimulant rather than replacing it.

Clonidine: off-label use for ADHD in Australia

Clonidine is an older alpha-2 adrenergic agonist that is not TGA-approved for ADHD in Australia. Its use for ADHD is considered off-label, meaning your GP prescribes it based on clinical judgement rather than a formal ADHD indication.

When clonidine is used for ADHD:

Primary role: managing stimulant-related insomnia or as an adjunct (add-on) to stimulants rather than as standalone ADHD treatment.
How it works: similar mechanism to guanfacine (alpha-2 agonist) but less selective. It acts on multiple alpha-2 receptor subtypes, which is why it causes more sedation and blood pressure effects.
Dosing: typically 50 to 150 micrograms at bedtime when used for ADHD-related sleep difficulties.
Side effects: significant sedation, dry mouth, low blood pressure, dizziness, and constipation. The sedation profile is heavier than guanfacine.
PBS status: clonidine is PBS-listed for hypertension but not for ADHD. Patients pay full price when it is prescribed for ADHD.

Most GPs will try atomoxetine or guanfacine before considering clonidine for ADHD, given the stronger evidence base for the first two.

PBS listing and cost in Australia

PBS subsidies for non-stimulant ADHD medications in Australia have significant restrictions that affect adult patients. Understanding these restrictions helps you plan the cost of treatment.

Atomoxetine (Strattera): PBS-subsidised only for patients who were diagnosed with ADHD between ages 6 and 18 and are continuing treatment into adulthood. Adults diagnosed after age 18 do not qualify for PBS subsidy and pay the full private prescription cost, which ranges from $80 to $150 per month depending on dose and pharmacy.
Guanfacine (Intuniv): same PBS restriction as atomoxetine. Subsidised only when ADHD was diagnosed before age 18 and treatment continues. Adults diagnosed later pay full price.
Clonidine: PBS-listed for hypertension, not for ADHD. If prescribed off-label for ADHD, patients pay the private price, though clonidine is relatively inexpensive (under $20 per month).

These PBS restrictions are a known gap in adult ADHD care in Australia. Adults diagnosed for the first time after 18 face higher out-of-pocket costs for non-stimulant medications. Your GP can discuss the cost implications when recommending treatment options.

Stimulant vs non-stimulant: key differences

The main differences between stimulant and non-stimulant ADHD medications affect how you experience treatment day to day.

Speed of onset: stimulants work within 30 to 90 minutes of the first dose. Atomoxetine takes 4 to 6 weeks for meaningful effect. Guanfacine takes 2 to 4 weeks.
Daily experience: stimulants have a noticeable on/off cycle (especially short-acting forms). Non-stimulants provide steady, continuous coverage with no wearing-off period.
Effectiveness: stimulants have a larger average effect size in clinical trials. Non-stimulants are effective but typically produce a more modest symptom reduction. This is an average, and individual responses vary.
Abuse potential: stimulants are Schedule 8 controlled substances in Australia. Non-stimulants are Schedule 4 because of less abuse potential.
Side effect profile: stimulants tend to cause appetite suppression and insomnia. Non-stimulants tend to cause sedation (guanfacine) or nausea (atomoxetine).
Prescribing requirements: stimulants require state-specific permits or authorities in most Australian states. Non-stimulants (atomoxetine, guanfacine, clonidine) have no permit requirements and can be prescribed by any GP.

Your GP will weigh these factors alongside your specific clinical picture to recommend the best option. For more on the first weeks of starting medication, see our week-by-week guide.

Frequently asked questions

Are non-stimulant ADHD medications as effective as stimulants?

Non-stimulant ADHD medications are effective but have a smaller average effect size than stimulants in clinical trials. Stimulants improve symptoms in 70 to 80 percent of adults, while non-stimulants show meaningful improvement in roughly 50 to 60 percent. Individual responses vary, and some patients respond better to a non-stimulant than to any stimulant. Your GP will base the choice on your specific clinical situation.

Can my GP prescribe non-stimulant ADHD medication in Australia?

Yes. Atomoxetine, guanfacine, and clonidine are all Schedule 4 medications in Australia. They do not require the state-based prescribing permits needed for stimulants. Any GP can prescribe them within their scope of practice. This makes non-stimulants particularly accessible for patients in states where GP stimulant prescribing is more restricted.

How long do I need to try atomoxetine before knowing if it works?

Atomoxetine requires a longer trial than stimulants. Initial effects appear within 1 to 2 weeks, but clinically meaningful improvement takes 4 to 6 weeks at an adequate dose. Full therapeutic benefit may take up to 12 weeks. Your GP will ask you to commit to at least a 6-week trial at the target dose (typically 80 mg daily) before deciding whether atomoxetine is working for you.

Can I take a non-stimulant and a stimulant together for ADHD?

Yes, combination therapy is sometimes used. Guanfacine is the most common non-stimulant added alongside a stimulant, particularly when hyperactivity, impulsivity, or stimulant-related insomnia are prominent. Atomoxetine is less commonly combined with stimulants. Your GP or psychiatrist will monitor the combination closely for side effects, particularly cardiovascular effects.

Why is atomoxetine not PBS-subsidised for adults diagnosed after 18?

The PBS restriction reflects the historical listing criteria, which tied subsidy to a childhood diagnosis continued into adulthood. Adults diagnosed for the first time after age 18 fall outside this criterion. This is widely recognised as a gap in Australian ADHD medication access. Without PBS subsidy, atomoxetine costs approximately $80 to $150 per month at full private prescription price. Advocacy groups including AADPA continue to push for expanded PBS listings for adult ADHD.

Non-stimulant medications are a real alternative for adults whose ADHD does not respond well to stimulants or who cannot tolerate them. The trade-off is a slower onset and typically a more modest effect size, but for the right patient, they provide stable, all-day symptom relief without the controlled-substance prescribing requirements. Talk to your GP about whether a non-stimulant is worth considering. If you are not yet assessed, book an ADHD assessment.

General health information

This article is general health information only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always speak with a qualified health professional before making any changes to your medication or treatment plan.

MySpecialistGP is a health information and GP directory service operated by Webbed Feet Pty Ltd. Read our Medical Disclaimer.