Adverse Reactions

Table: Adverse reactions reported by 5% or more of adults (ages 18 to 55 years) taking Mydayis and that were at least twice the incidence in patients taking placebo in the 4-, 6-, and 7-week clinical trials.1

Adverse Reactions in Adults

The most common adverse reactions (incidence ≥5% and at a rate at least twice placebo) in pediatric patients (13 to 17 years) with ADHD were decreased appetite (22% Mydayis n=78, 6% placebo n=79), insomnia (8%, 3%), nausea (8%, 4%), irritability (6%, 3%), and decreased weight (5%, 1%).

Safety data in adults are pooled from 3 controlled trials including dose-optimization and forced-dose titration studies with 626 adult patients exposed to Mydayis doses of 12.5 mg to 75 mg per day. Includes doses up to 75 mg (1.5 times the maximum adult dosage).

Discontinuation rates1

In the controlled trials of adult patients aged 18 to 55 years, 9% of Mydayis-treated patients discontinued due to adverse reactions, compared to 2% of placebo-treated patients. The most frequent adverse reactions leading to discontinuation of adult patients (i.e., leading to discontinuation in at least 1% of Mydayis-treated patients and at a rate at least twice that of placebo) were insomnia (2%), increased blood pressure (2%), decreased appetite (1%), and headache (1%).

In a controlled trial including adolescent patients (ages 13 to 17 years), 5% (4/78) of Mydayis-treated patients discontinued due to adverse reactions compared to 0% (0/79) of placebo-treated patients. The most frequent adverse reaction leading to discontinuation (i.e. leading to discontinuation in at least 1% of Mydayis-treated patients and at a rate at least twice that of placebo) were dizziness (1%, n=1), depression (1%, n=1), and abdominal pain upper (1%, n=1), and viral infection (1%, n=1).

Long-term Safety Study2

Long-term safety of Mydayis was studied in a 12-month open-label safety study in 505 adults aged 18 to 55 years who had completed 4 weeks or more of treatment in dose-optimization Study 301 or forced-dose titration Study 303. The tolerability and safety profile of Mydayis over this 12-month treatment period was comparable to that seen in short-term studies. Pharmacological treatment of ADHD may be needed for an extended period. Periodically re-evaluate the long-term use of Mydayis and adjust dosage as needed.


Advise the patient to read the FDA-approved patient labeling (Medication Guide).

Controlled Substance Status/High Potential for Abuse and Dependence

  • Advise patients and their caregivers that Mydayis is a federally controlled substance because it can be abused or lead to dependence. Advise patients to store Mydayis in a safe place, preferably locked, to prevent abuse. Advise patients to comply with laws and regulations on drug disposal. Advise patients to dispose of remaining, unused, or expired Mydayis by a medicine take-back program if available.

Serious Cardiovascular Risks

  • Advise patients, caregivers, and family members that there is a potential serious cardiovascular risk including sudden death, myocardial infarction, stroke, and hypertension, with Mydayis use. Instruct patients to contact a healthcare provider immediately if they develop symptoms such as exertional chest pain, unexplained syncope, or other symptoms suggestive of cardiac disease.

Blood Pressure and Heart Rate Increases

  • Instruct patients that Mydayis can cause elevations of their blood pressure and pulse rate and they should be monitored for such effects.

Psychiatric Risks

  • Advise patients that Mydayis, at recommended doses, may cause psychotic or manic symptoms, even in patients without prior history of psychotic symptoms or mania.

Long-Term Suppression of Growth

  • Advise patients, family members, and caregivers that amphetamines may cause slowing of growth, including weight loss.

Circulation Problems in Fingers and Toes (Peripheral Vasculopathy, Including Raynaud’s Phenomenon)

  • Instruct patients beginning treatment with Mydayis about the risk of peripheral vasculopathy, including Raynaud’s phenomenon, and associated signs and symptoms: fingers or toes may feel numb, cool, painful, and/or may change from pale, to blue, to red. Instruct patients to report to their physician any new numbness, pain, skin color change, or sensitivity to temperature in fingers or toes. Instruct patients to call their physician immediately with any signs of unexplained wounds appearing on fingers or toes while taking Mydayis. Further clinical evaluation (e.g., rheumatology referral) may be appropriate for certain patients.


  • Caution patients that Mydayis may lower the convulsive threshold. Advise patients to contact their healthcare provider immediately and to discontinue Mydayis if a seizure occurs.

Serotonin Syndrome

  • Caution patients about the risk of serotonin syndrome with concomitant use of Mydayis and other serotonergic drugs including SSRIs, SNRIs, triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, buspirone, St. John’s Wort, and with drugs that impair metabolism of serotonin (in particular MAOIs, both those intended to treat psychiatric disorders and also others such as linezolid). Advise patients to contact their healthcare provider or report to the emergency room if they experience signs or symptoms of serotonin syndrome.

Concomitant Medications

  • Advise patients to notify their physicians if they are taking, or plan to take, any prescription or over-the-counter drugs because there is a potential for interactions.


  • Advise patients of the potential fetal effects from the use of Mydayis during pregnancy. Advise patients to notify their healthcare provider if they become pregnant or intend to become pregnant during treatment with Mydayis.
  • There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to Mydayis during pregnancy. Healthcare providers are encouraged to register patients by calling the National Pregnancy Registry for Psychiatric Medications at 1-866-961-2388 or visiting online at​research/pregnancyregistry/.


  • Advise women not to breastfeed if they are taking Mydayis.


  • Advise patients to avoid alcohol while taking Mydayis. Consumption of alcohol while taking Mydayis may result in a more rapid release of the dose of mixed amphetamine salts.

This patient counseling information does not include all the information needed to use Mydayis. See Full Prescribing Information.

  1. Mydayis [package insert]. Lexington, MA; Takeda US Inc.
  2. Adler LA, Frick G, Yan B. A long-term, open-label, safety study of triple-bead mixed amphetamine salts (SHP465) in adults with ADHD. J Atten Disord. 2017; doi:10.1177/1087054717696770.