Azstarys (Dexmethylphenidate/Serdexmethylphenidate) Side Effects: What to Expect and When to Call Your Doctor

Azstarys (dexmethylphenidate/serdexmethylphenidate) is generally well-tolerated for ADHD treatment, but like all stimulant medications, it carries a range of possible side effects — from common and manageable to rare but serious. This guide helps you understand what to expect when starting Azstarys, which side effects are worth monitoring, and when to call your doctor immediately.

Boxed Warning: Risk of Misuse, Addiction, and Overdose

Azstarys carries a

boxed warning — the FDA's most serious warning — about the risk of abuse, misuse, and addiction. CNS stimulants including Azstarys have high potential for misuse, which can lead to substance use disorder and addiction. Misuse (especially snorting or injecting) can cause overdose and death. Take Azstarys exactly as prescribed and store it in a secure location.

Most Common Side Effects of Azstarys

Based on accumulated data from methylphenidate products including Azstarys, the most common side effects (occurring in more than 5% of patients and at twice the rate of placebo) include:

Decreased appetite: One of the most common stimulant side effects. Taking Azstarys with breakfast can help; eating a protein-rich meal before your morning dose may reduce this effect.

Insomnia: Taking Azstarys late in the day can make falling asleep difficult. Azstarys should always be taken in the morning.

Nausea and vomiting: Often improve as the body adjusts to the medication. Taking with food may help.

Abdominal pain/dyspepsia: Stomach discomfort, particularly early in treatment.

Weight loss: Related to appetite suppression. In children, growth (height and weight) should be monitored periodically.

Anxiety and irritability: Stimulants can increase anxiety in some patients. Dose adjustment or medication change may be needed.

Dizziness: May occur, particularly when standing quickly (orthostatic effects).

Affect lability: Mood swings or emotional sensitivity, particularly as the medication is wearing off in the evening (sometimes called "rebound").

Tachycardia (rapid heart rate): A mild increase in heart rate is common with stimulants. Report persistent, severe, or symptomatic tachycardia to your doctor.

Increased blood pressure: Blood pressure should be monitored periodically during Azstarys treatment.

Serious Side Effects — Call Your Doctor Right Away

Some Azstarys side effects require immediate medical attention:

Cardiovascular events: Chest pain, shortness of breath, fainting, or irregular heartbeat. Sudden death has occurred in patients with pre-existing structural cardiac abnormalities. Seek emergency care immediately.

Psychiatric reactions: New or worsened psychosis, hallucinations, mania, aggressive behavior, or suicidal thoughts. Stimulants can trigger psychiatric symptoms even without prior history.

Peripheral vasculopathy/Raynaud's phenomenon: Numbness, pain, or color changes (white/blue/red) in fingers or toes, especially in cold temperatures. Report to your doctor.

Priapism: Painful, prolonged erection not caused by sexual stimulation. Rare but serious — seek emergency care immediately.

Growth suppression in children: Pediatric patients should have height and weight monitored regularly. If a child is not growing or gaining weight as expected, the prescriber may recommend a medication break or dose adjustment.

Severe allergic reactions: Bronchospasm, rash, angioedema (swelling of the face/lips/throat), or anaphylaxis. Seek emergency care immediately if these occur.

Worsening of tics or Tourette's syndrome: Azstarys can worsen motor and verbal tics. Assess family history for tics before starting treatment.

Who Should Not Take Azstarys?

Azstarys is contraindicated in patients who:

Have a known hypersensitivity to serdexmethylphenidate, methylphenidate, or any Azstarys ingredients

Are currently taking or have taken an MAOI within the past 14 days (risk of hypertensive crisis)

Have known serious heart problems or structural cardiac abnormalities (consult cardiologist before use)

Tips for Managing Common Azstarys Side Effects

Appetite suppression: Eat a full breakfast before your morning dose. Plan a larger, nutritious meal in the evening when appetite returns.

Sleep difficulties: Always take Azstarys in the morning. Good sleep hygiene (consistent bedtime, dark room, no screens) can help. Talk to your doctor if insomnia persists.

Nausea: Try taking Azstarys with food. The nausea usually improves in the first few weeks.

For information about medications that can interact with Azstarys, see our guide: Azstarys Drug Interactions: What to Avoid. And if you need help finding Azstarys at a pharmacy near you,

medfinder can help.