CNS stimulant (amphetamine prodrug)Prescription required in Canada

Vyvanselisdexamfetamine dimesylate

A once-daily controlled stimulant for ADHD, taken in the morning; it is a prodrug, so it activates gradually.

Quick answer

What it is: A long-acting stimulant and a prodrug — lisdexamfetamine is inactive until the body converts it to dexamfetamine, which gives it a smoother onset.
What it's used for: ADHD in children, adolescents and adults, and (in some patients) binge eating disorder.
Worth knowing: Taken once in the morning. Capsules can be opened and mixed into water or soft food if swallowing is difficult.
Main safety point: It is a controlled substance in Canada with specific prescribing and refill rules. Appetite loss and trouble sleeping are the most common issues; blood pressure and heart rate are monitored.

Vyvanse is worth a proper medication review Pill4Me pharmacists in Chilliwack can help.

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Drug class

CNS stimulant (amphetamine prodrug)

Use in Canada

4,000,000 prescriptions

DIN (Canada)

02310066, 02310074 +4 more

What is Vyvanse?

Vyvanse is used to treat Attention Deficit Hyperactivity Disorder (ADHD) in children age 6 and older, adolescents, and adults. It is also approved in Canada for the treatment of moderate-to-severe binge eating disorder (BED) in adults.

How Vyvanse works

Lisdexamfetamine is an inactive prodrug — after you swallow it, enzymes in the blood convert it into active d-amphetamine. Amphetamine increases the levels of dopamine and norepinephrine in the brain, which improves attention, focus, impulse control, and executive function in people with ADHD. The prodrug design means it has a slower onset and longer, smoother effect than older amphetamines.

Forms and strengths

Capsules: 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg. Can be swallowed whole or opened and the contents dissolved in water and consumed immediately (do not store the mixture).

How Vyvanse is taken

Taken once daily in the morning (taking it later in the day can cause insomnia). Start at 20–30 mg and adjust in increments every 1–2 weeks based on response. Maximum dose is 70 mg/day. Take with or without food — taking with food may reduce appetite suppression during the day. As a controlled substance, prescriptions must be hand-signed by a physician and cannot be faxed or called in. A 30-day supply at a time is typical.

This is general information, not a dose for you. Dosing depends on the reason you are taking it, your kidney and liver function, your age, and everything else you take — follow the directions on your own label, and ask us if they differ from what you read here.

If you miss a dose

If you remember in the morning or early part of the day, you can usually take it then. If it is already afternoon or evening, it is normally better to skip that day's dose — taking a stimulant late commonly causes insomnia. Never take two doses to catch up. Because this is a controlled medication, talk to your prescriber if doses are being missed regularly.

Side effects

Common — usually manageable

Decreased appetite — often significant; monitor weight in children
Difficulty falling asleep (insomnia)
Dry mouth
Headache
Increased heart rate and blood pressure
Anxiety, irritability, or feeling tense
Stomach upset or nausea
Emotional rebound ('coming down') in the late afternoon

Get medical help for these

New or worsening psychiatric symptoms — psychosis, hallucinations, paranoia, aggression; seek immediate care
Cardiovascular events — rare but serious in people with underlying heart conditions; sudden death has been reported in patients with structural heart abnormalities
Suppression of growth in children — height and weight must be monitored at every visit
Serotonin syndrome — if combined with serotonergic medications; symptoms include agitation, rapid heart rate, fever, muscle twitching
Peripheral vasculopathy (including Raynaud's phenomenon) — fingers or toes that turn blue or white in cold

Important warnings

Vyvanse is a controlled substance with potential for abuse and dependence — it should only be used as prescribed, stored securely, and never shared with others

Evaluate for underlying heart conditions before starting — inform your doctor of any personal or family history of heart disease, arrhythmias, or sudden unexplained death

Children must have height, weight, and blood pressure monitored regularly — growth suppression can occur with long-term use

MAOIs are absolutely contraindicated — do not take Vyvanse within 14 days of stopping an MAOI (this combination can cause a potentially fatal hypertensive crisis)

Misuse can lead to serious cardiovascular events and dependence — amphetamines are Schedule I controlled substances in Canada

Who should take extra care

Heart conditions: Structural heart disease, cardiomyopathy or serious arrhythmias need assessment before a stimulant is started.
High blood pressure: Stimulants raise blood pressure and heart rate, so both are checked at follow-up visits.
History of substance use: Amphetamines carry dependence and misuse potential and are tracked under Canada's controlled drug rules.
Anxiety, psychosis or bipolar disorder: Stimulants can worsen these — this needs to be part of the prescribing conversation.
Children and growth: Appetite suppression and growth are monitored over time in children and adolescents.
MAO inhibitors: Must not be combined, and a washout period is required after stopping an MAOI.

Who should not take it

Use of a monoamine oxidase inhibitor (MAOI) within the last 14 days — this combination is potentially life-threatening
Advanced arteriosclerosis, symptomatic cardiovascular disease, or moderate-to-severe high blood pressure
Hyperthyroidism (overactive thyroid)
History of drug abuse or dependence — use with extreme caution and close monitoring
Agitated states
Known allergy or sensitivity to amphetamine

Drug interactions

MAOIs (phenelzine, tranylcypromine, selegiline) — absolutely contraindicated, life-threatening hypertensive crisis possible; 14-day washout required. Antacids and urinary alkalinizers (sodium bicarbonate) increase amphetamine absorption and extend its effects. Acidifying agents (vitamin C, ammonium chloride) reduce amphetamine levels. Blood pressure medications may be less effective. SSRIs and SNRIs used together may increase risk of serotonin syndrome. Tricyclic antidepressants may increase cardiovascular effects.

This is not a complete list. If you take several medications, or buy anything over the counter, a pharmacist medication review is the reliable way to catch interactions that matter.

Coverage in British Columbia

Vyvanse (lisdexamfetamine) may be covered under BC PharmaCare depending on your plan. Covered under Fair PharmaCare for eligible BC residents. Children and adults with psychiatric diagnoses may also qualify for Psychiatric Medications (Plan G) coverage if annual income is under $42,000 — your prescriber applies on your behalf. Coverage amounts vary — Fair PharmaCare covers 70–100% after your annual deductible depending on your income. Call us at 604-705-3644 and we'll check your specific coverage in minutes. No generic version is currently available in Canada. BC PharmaCare covers the brand name where it is on the formulary. Coverage information is a general guide only. Your actual coverage depends on your PharmaCare plan and eligibility. We check coverage for free — call 604-705-3644 or ask at the counter.

Coverage may depend on indication, PharmaCare plan and Special Authority requirements. Ask Pill4Me Pharmacy to check your coverage, or see BC PharmaCare.

Frequently asked questions

Is Vyvanse addictive?

Vyvanse is a Schedule I controlled substance in Canada because amphetamines have potential for abuse and psychological dependence. However, when taken as prescribed by a person with ADHD at therapeutic doses, the risk of developing addiction is low. The prodrug design slows absorption compared to older stimulants, reducing abuse potential. Never take more than prescribed, do not crush or tamper with capsules, and store securely away from others.

Should my child take a break from Vyvanse over the summer?

This is a decision to make with your child's doctor. Planned breaks (called 'drug holidays') during school vacations are sometimes recommended to give the body a rest, allow for growth catch-up, and assess whether the medication is still needed. However, some children have significant difficulties with behaviour, emotional regulation, or safety even without academic demands, and benefits extend beyond school. There is no universal recommendation — it depends on the individual child.

What time of day should I take Vyvanse?

Take Vyvanse first thing in the morning, immediately on waking. Because it is a long-acting medication (typically working for 10–14 hours), taking it in the afternoon or evening is very likely to cause insomnia. If you find it affects your ability to fall asleep even when taken in the morning, discuss this with your doctor — a dose adjustment or earlier timing may help.

Why does my child seem sad or irritable when Vyvanse wears off?

This is called 'rebound' and occurs as the medication level drops in the late afternoon. It can cause irritability, emotional sensitivity, increased hyperactivity, or low mood for 30–60 minutes. It is common and does not mean the medication is wrong for your child. Strategies include a consistent wind-down routine, a snack when the medication wears off, and discussing with your doctor whether an adjusted formulation or dose timing helps.

My child is not eating — what should I do?

Appetite suppression is one of the most common effects of stimulant medications and is most pronounced in the middle of the day when medication levels are highest. Strategies that help: offer a substantial breakfast before the medication kicks in (within 30 minutes of waking), provide a large nutritious snack or meal in the evening when appetite returns, and avoid forcing meals at lunch. Monitor weight regularly with your doctor — if growth is being affected, a dose adjustment or holiday may be recommended.

Vyvanse is worth a proper medication review

Interactions matter more with this one. A pharmacist can go through everything you take — including anything you buy over the counter — and flag what needs attention before it becomes a problem.

Book a medication review Transfer my prescription Call 604-705-3644

Pill4Me Pharmacy is at 5625 Promontory Rd Unit 101, Chilliwack, BC. We deliver free to Chilliwack, Sardis, Promontory, Vedder and Yarrow, and you can reach a pharmacist directly at 604-705-3644.