Mydayis Dosage, forms & strengths
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Mydayis (amphetamine/dextroamphetamine) is a long-acting central nervous system stimulant that is manufactured by Shire, LLC. It is FDA-approved to treat Attention Deficit Hyperactivity Disorder (ADHD) in patients 13 years and older. Mixed amphetamine salts such as amphetamine and dextroamphetamine are also used to treat narcolepsy.
How does Mydayis work?
Amphetamine products such as Mydayis are sympathomimetic amines that increase the concentrations of dopamine and norepinephrine in your brain. It is thought that high levels of these neurotransmitters are why Mydayis works in the treatment of ADHD to improve your ability to focus, pay attention, and control your hyperactive behavior.
Mydayis dosage forms and strengths
Mydayis is available as an extended-release capsule in the following strengths:
- 12.5mg extended-release capsule
- 25mg extended-release capsule
- 37.5mg extended-release capsule
- 50mg extended-release capsule
The recommended starting dose of Mydayis is typically taken once daily right after you wake up. It can be taken with or without food but should be taken the same way each time.
Mydayis adult dosage chart
Recommended starting dose
Maximum daily dose
12.5mg by mouth once daily.
Mydayis pediatric dosage chart
Recommended Starting Dose
Maximum Daily Dose
13-17 years of age
12.5mg by mouth once daily.
Mydayis dosage restrictions
- The maximum daily dose of Mydayis in adult patients with severe renal impairment is 25mg.
- The maximum dose in pediatric patients with severe renal impairment is 12.5mg daily.
- Mydayis use is not recommended in adult or pediatric patients with end-stage renal disease (ESRD).
How to take Mydayis
- Read the Full Prescribing Information, Instructions for Use, and Medication Guide that comes with your Mydayis.
- Take Mydayis exactly as your healthcare professional prescribes it to you. Do not change your dose or stop taking Mydayis without discussing it with them.
- Mydayis is typically taken once daily in the morning right after waking up. You can take Mydayis with or without food but should take it the same way each time.
- You should swallow the Mydayis capsules whole. If you have difficulties swallowing, you can open up the capsule and sprinkle it over a spoonful of applesauce. The mixture should then be swallowed immediately without chewing. Do not store the Mydayis and applesauce mixture for later use.
- If you miss a dose of Mydayis, skip the missed dose and take your dose the next morning at your regular time. Do not take Mydayis later in the day to make up for a missed dose.
- Your doctor may periodically stop your Mydayis treatment to check your ADHD symptoms.
- If you think you or your child has taken too much Mydayis, contact your doctor or go to the nearest emergency room immediately. Symptoms of too much Mydayis include restlessness, tics (muscle twitches), rapid breathing, confusion, hallucinations, and muscle weakness.
Mydayis dosage FAQs
What are some common side effects of Mydayis?
The most common adverse reactions of Mydayis include:
- Trouble sleeping
- Loss of appetite
- Weight loss
- Dry mouth
- Increased heart rate
- High blood pressure
Mydayis can cause serious side effects including:
- Life-threatening allergic reactions including angioedema, and trouble breathing
- Serious heart problems such as chest pain and arrhythmias
- Numb, cold, or pale fingers and toes
Contact your doctor for medical advice about any side effects you experience while taking Mydayis. You can report your side effects to the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
What are some drug interactions with Mydayis?
When Mydayis is taken with other drugs, it may change the way they work or increase the frequency and severity of side effects. Make sure your doctor is aware of all prescription drugs, over-the-counter medications, vitamins, and herbal supplements you take. Some major drug interactions with Mydayis include:
- Antidepressants – SSRIs (paroxetine, fluoxetine), SNRIs, TCAs (protriptyline), and MAOIs (tranylcypromine)
- Other stimulant medications
- Omeprazole, esomeprazole, cimetidine, and other stomach medications
- Migraine medications – triptans
- St. John’s wort
Are there any contraindications or precautions with Mydayis?
Mydayis should not be used if you have a known hypersensitivity to amphetamine formulations or any inactive ingredients in Mydayis. It should also be avoided if you have used a monoamine oxidase inhibitor (MAOI) within the previous 14 days.
Mydayis also carries certain warnings that should be monitored and treated if indicated, such as:
- Sudden death has occurred with the use of CNS stimulants such as Mydayis in pediatric patients with structural heart defects or other serious heart problems. Stroke, heart attack, and sudden death have also been reported in adults. Mydayis should be avoided in patients with structural heart abnormalities and other serious heart problems.
- Mydayis can increase your blood pressure and heart rate so you should monitor your BP and pulse.
- Mydayis use can cause mental health issues such as psychosis or manic symptoms, even if you have no prior history of bipolar disorder.
- Pediatric patients should have their height and weight monitored during treatment as Mydayis may cause long-term growth suppression.
- Mydayis may cause circulation problems (Raynaud’s phenomenon), especially in the fingers and toes. You should be monitored for any changes in circulation.
- Mydayis may lower the seizure threshold and should be discontinued if a seizure occurs.
- There is an increased risk of serotonin syndrome with Mydayis, especially if taken with other serotonergic drugs such as SSRIs and SNRIs. If this occurs, Mydayis should be discontinued and you should seek immediate medical assistance.
- Mydayis is a controlled substance that has a high potential for drug abuse and dependence. Your risk should be assessed before starting treatment and then monitored while taking Mydayis.
- If you suddenly stop using Mydayis, you can have withdrawal symptoms. Notify your doctor immediately if you experience symptoms such as extreme fatigue, headache, anxiety, depression.
How long does Mydayis stay in your system?
Mydayis has a half-life of between 10 to 13 hours so it will stay in your circulation for almost 3 days.
How long does it take for Mydayis to start working?
Mydayis typically works very quickly. It starts working about 2 hours after taking a dose and can last up to 16 hours.
Can I drink alcohol while taking Mydayis?
You should avoid drinking alcohol while taking Mydayis. Alcohol may cause a more rapid release of the dose of Mydayis.
Will I have withdrawal symptoms if I stop taking Mydayis?
Withdrawal symptoms such as extreme fatigue and depression may occur if you suddenly stop taking Mydayis. Your doctor should taper you off Mydayis slowly to avoid these symptoms.
Is it safe to use Mydayis while pregnant or breastfeeding?
There is limited data on the use of amphetamine salts during pregnancy but based on animal studies may cause fetal harm. There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to MYDAYIS during pregnancy. You can register online through the National Pregnancy Registry for Psychiatric Medications or by calling 1-866-961-2388.
Amphetamines are found in breast milk and based on the potential for adverse reactions, Mydayis use during lactation is not recommended. You should always discuss the risks and benefits of any medication with your healthcare provider if you are pregnant, plan on becoming pregnant, or are breastfeeding.
Is there a generic for Mydayis?
Currently, there is a generic for Mydayis available on the market. However, you will still pay less for brand-name Mydayis through NiceRx if eligible for assistance.
Related resources for Mydayis dosage
The content on this website is intended for information purposes only. It does not constitute medical advice. The information on this website should not be relied upon and is not a substitute for professional medical advice. You should always speak to your doctor regarding the risks and benefits of any treatment.