Sunosi: Uses, Dosage & Side Effects
A dopamine and norepinephrine reuptake inhibitor for the treatment of excessive daytime sleepiness in adults with narcolepsy or obstructive sleep apnea
Sunosi (solriamfetol) is a prescription wakefulness-promoting agent used to improve wakefulness and reduce excessive daytime sleepiness (EDS) in adults with narcolepsy or obstructive sleep apnea (OSA). It works by inhibiting the reuptake of dopamine and norepinephrine in the brain, increasing the availability of these key neurotransmitters that promote alertness. Sunosi is taken once daily in the morning as a film-coated tablet, with the maximum recommended dose being 150 mg per day. For OSA patients, Sunosi does not replace primary therapies such as CPAP and should be used alongside them. Clinical trials have demonstrated that Sunosi significantly improves wakefulness as measured by the Maintenance of Wakefulness Test (MWT) and reduces subjective sleepiness as measured by the Epworth Sleepiness Scale (ESS).
Quick Facts: Sunosi
Key Takeaways
- Sunosi (solriamfetol) is a dual dopamine and norepinephrine reuptake inhibitor specifically approved to improve wakefulness in adults with excessive daytime sleepiness due to narcolepsy or obstructive sleep apnea (OSA).
- The medication is taken once daily in the morning upon waking, with starting doses of 75 mg for narcolepsy and 37.5 mg for OSA, up to a maximum of 150 mg per day. Dose adjustments may be needed for patients with kidney impairment.
- Sunosi does not replace primary OSA therapy such as CPAP; patients should continue using their CPAP device or other primary treatment while taking Sunosi.
- Common side effects include headache, anxiety, insomnia, nausea, and increased blood pressure or heart rate. The medication is contraindicated with MAO inhibitors and in patients with uncontrolled hypertension or serious cardiac conditions.
- Clinical trials (TONES studies) demonstrated statistically significant improvements in objective wakefulness (MWT) and subjective sleepiness (ESS) in both narcolepsy and OSA patient populations, with effects sustained over long-term treatment.
What Is Sunosi and What Is It Used For?
Sunosi contains the active substance solriamfetol (as solriamfetol hydrochloride), a selective dual-acting dopamine and norepinephrine reuptake inhibitor (DNRI). Unlike traditional stimulants that broadly release catecholamines, solriamfetol works through a more targeted mechanism by binding to and inhibiting the dopamine transporter (DAT) and norepinephrine transporter (NET). This prevents the reuptake of these two critical wakefulness-promoting neurotransmitters from the synaptic cleft back into the presynaptic neuron, thereby increasing their extracellular concentrations. The result is enhanced dopaminergic and noradrenergic signaling in the brain circuits that regulate wakefulness and arousal.
Dopamine and norepinephrine are among the most important neurotransmitters involved in the regulation of the sleep-wake cycle. Dopamine, produced primarily in the ventral tegmental area and substantia nigra, plays a central role in promoting wakefulness, motivation, and cognitive function. Norepinephrine, produced in the locus coeruleus, is a key driver of arousal, attention, and vigilance. In conditions such as narcolepsy and obstructive sleep apnea, disruptions in these neurotransmitter systems contribute significantly to the hallmark symptom of excessive daytime sleepiness. By selectively enhancing both dopaminergic and noradrenergic transmission, solriamfetol addresses the neurochemical basis of EDS in a targeted manner.
Sunosi is approved for two primary indications in adults. First, it is used for the treatment of excessive daytime sleepiness in adults with narcolepsy, a chronic neurological disorder characterized by the brain's inability to regulate sleep-wake cycles normally. Narcolepsy affects approximately 25 to 50 per 100,000 people worldwide and can manifest as sudden, irresistible episodes of sleepiness during the day, cataplexy (sudden loss of muscle tone triggered by emotions), sleep paralysis, and hypnagogic hallucinations. While Sunosi does not treat cataplexy directly, it significantly reduces the excessive daytime sleepiness that is often the most disabling symptom of narcolepsy.
Second, Sunosi is approved for improving wakefulness and reducing excessive daytime sleepiness in adults with obstructive sleep apnea (OSA) whose EDS has not been satisfactorily treated with primary OSA therapy such as continuous positive airway pressure (CPAP). OSA is one of the most common sleep disorders, affecting an estimated 936 million adults globally according to the International Classification of Sleep Disorders. It is characterized by repeated episodes of partial or complete upper airway obstruction during sleep, leading to intermittent hypoxia, sleep fragmentation, and consequently excessive daytime sleepiness. Importantly, Sunosi does not treat the underlying airway obstruction in OSA; it is an adjunctive therapy that addresses residual EDS that persists despite adequate CPAP or other primary treatment. Patients must continue their primary OSA therapy while taking Sunosi.
The efficacy of Sunosi was established in the TONES (Treatment of Obstructive Sleep Apnea and Narcolepsy Excessive Sleepiness) clinical trial program, which included multiple randomized, double-blind, placebo-controlled Phase III studies:
- TONES 2 (Narcolepsy): This pivotal trial enrolled 236 adults with narcolepsy. Patients treated with solriamfetol (75 mg or 150 mg once daily) showed statistically significant improvements in the Maintenance of Wakefulness Test (MWT), which objectively measures a patient's ability to stay awake in a quiet, darkened room. The 150 mg dose produced a mean change from baseline of +12.3 minutes on the MWT, compared with +2.1 minutes for placebo. Subjective sleepiness, measured by the Epworth Sleepiness Scale (ESS), also improved significantly.
- TONES 3 (OSA): This trial enrolled 459 adults with OSA who had residual EDS despite adequate primary therapy. Solriamfetol at doses of 37.5 mg, 75 mg, and 150 mg showed dose-dependent improvements in both MWT and ESS scores. The 150 mg dose produced a mean MWT change from baseline of +10.7 minutes versus +0.2 minutes for placebo. The Patient Global Impression of Change (PGI-C) scale also showed significantly greater improvement compared with placebo.
- TONES 4 (Long-term safety): This 52-week open-label extension study demonstrated that the wakefulness-promoting effects of solriamfetol were maintained over long-term use without evidence of tolerance or tachyphylaxis. Adverse events were consistent with those observed in the shorter-term controlled trials.
Solriamfetol was first approved by the U.S. Food and Drug Administration (FDA) in March 2019 under the brand name Sunosi, and subsequently by the European Medicines Agency (EMA) in January 2020. It is now available in numerous countries worldwide. Sunosi represents an important treatment option for patients with EDS due to narcolepsy or OSA, offering a novel mechanism of action distinct from other wakefulness-promoting agents such as modafinil and pitolisant.
For patients with obstructive sleep apnea, Sunosi is intended as an adjunctive therapy to address residual excessive daytime sleepiness that persists despite adequate use of primary OSA treatment (such as CPAP). Sunosi does not treat the underlying airway obstruction. Patients should continue using their CPAP device or other prescribed primary therapy alongside Sunosi to manage their OSA effectively.
What Should You Know Before Taking Sunosi?
Contraindications
There are several situations in which Sunosi must not be used. Understanding these contraindications is essential for patient safety. Your doctor will assess your medical history carefully before prescribing this medication to ensure it is appropriate for you.
- You are allergic to solriamfetol or any other ingredient in Sunosi
- You have had a heart attack (myocardial infarction) within the past year
- You have serious heart problems, including new or worsening chest pain (unstable angina), uncontrolled high blood pressure, severe irregular heart rhythm, or other serious cardiovascular conditions
- You are currently taking a monoamine oxidase inhibitor (MAOI) for depression or Parkinson's disease, or have taken an MAOI within the past 14 days
The contraindication with MAO inhibitors is particularly important because the combination of an MAOI with a dopamine and norepinephrine reuptake inhibitor can lead to a dangerous, potentially life-threatening increase in blood pressure known as a hypertensive crisis. MAOIs include medications such as phenelzine, tranylcypromine, isocarboxazid, selegiline (at certain doses), and linezolid (an antibiotic with MAOI properties). If you are transitioning from an MAOI to Sunosi, a washout period of at least 14 days must be observed to allow the MAOI to be fully eliminated from the body.
The cardiovascular contraindications reflect the fact that solriamfetol, by increasing dopamine and norepinephrine levels, can raise blood pressure and heart rate. In patients with pre-existing serious cardiac conditions, this could exacerbate the underlying disease and increase the risk of adverse cardiovascular events. Before starting Sunosi, your doctor will typically assess your blood pressure, heart rate, and cardiovascular health to determine whether treatment is safe for you.
Warnings and Precautions
Even if none of the absolute contraindications apply, certain conditions require careful consideration and monitoring before and during treatment with Sunosi. Tell your doctor or pharmacist before starting Sunosi if you have or have ever had any of the following:
- Psychiatric disorders: This includes psychosis (loss of contact with reality), bipolar disorder (severe mood swings), depression, anxiety disorders, or suicidal ideation. Solriamfetol's effects on dopamine and norepinephrine signaling could potentially worsen certain psychiatric symptoms. Patients should be monitored for emergence or exacerbation of psychiatric symptoms during treatment.
- Cardiovascular problems: Including any history of heart attack, stroke, heart failure, or arrhythmias. While the absolute contraindications cover the most serious cardiac conditions, patients with any cardiovascular history require careful blood pressure and heart rate monitoring, particularly during dose titration.
- High blood pressure (hypertension): Sunosi can cause dose-dependent increases in blood pressure. Patients with pre-existing hypertension should have their blood pressure adequately controlled before starting treatment, and should be monitored regularly throughout treatment. In clinical trials, mean increases in systolic blood pressure of 1 to 5 mmHg and diastolic blood pressure of 1 to 3 mmHg were observed with Sunosi compared with placebo.
- History of alcoholism, drug or medication misuse, or dependence: Although the abuse potential of solriamfetol appears to be lower than that of traditional psychostimulants (such as amphetamine), the medication does affect dopaminergic pathways, which are involved in reward and reinforcement. In human abuse potential studies, solriamfetol at supratherapeutic doses produced some positive subjective effects, though less than those of phentermine. Patients with a history of substance use disorders should be monitored for signs of misuse or dependence.
- Narrow-angle glaucoma: The noradrenergic effects of solriamfetol can cause pupillary dilation (mydriasis), which in patients with untreated narrow-angle glaucoma may precipitate an acute angle-closure attack. If you have this eye condition, your ophthalmologist and prescribing physician should coordinate care before starting Sunosi.
Your doctor will schedule regular follow-up appointments to monitor how Sunosi is affecting you, including checks on your blood pressure, heart rate, and overall cardiovascular health. At the beginning of treatment and with each dose change, you should be particularly attentive to any new or worsening symptoms.
Pregnancy and Breastfeeding
Sunosi should not be used during pregnancy or by women of childbearing potential who are not using effective contraception. The effects of solriamfetol on human pregnancy have not been adequately studied. Although animal reproduction studies have not demonstrated teratogenicity, a precautionary approach is recommended because the potential risks to the human fetus cannot be fully excluded. If you are pregnant or think you may be pregnant, do not take Sunosi and consult your doctor immediately about alternative management strategies.
If you are breastfeeding, you should not take Sunosi. It is not known whether solriamfetol passes into human breast milk, and a risk to the nursing infant cannot be excluded. You and your doctor must jointly decide whether to discontinue breastfeeding or to discontinue Sunosi therapy, taking into account the benefit of breastfeeding for your baby and the benefit of treatment for you. If you are planning to become pregnant or to breastfeed, discuss this with your doctor well in advance so that appropriate treatment adjustments can be made.
Children and Adolescents
Sunosi is not recommended for use in children and adolescents under 18 years of age. The safety and efficacy of solriamfetol have not been established in this age group. Pediatric clinical studies have not been completed, and the potential effects of this medication on the developing brain and body have not been adequately characterized. If your child has excessive daytime sleepiness due to narcolepsy or another sleep disorder, consult with a pediatric sleep medicine specialist about appropriate treatment options.
Driving and Operating Machinery
While Sunosi is designed to improve wakefulness, the medication may itself cause dizziness or difficulty concentrating in some patients, particularly when starting treatment or when the dose is changed. You should exercise particular caution when driving or operating machinery until you have established how Sunosi affects you individually. The underlying sleep disorder (narcolepsy or OSA) can also significantly impair your ability to drive or operate machinery safely. Discuss with your doctor whether it is safe for you to perform activities that require sustained alertness, especially at the beginning of treatment and during dose adjustments.
How Does Sunosi Interact with Other Drugs?
Understanding potential drug interactions is essential for the safe use of Sunosi. Because solriamfetol increases dopamine and norepinephrine levels in the brain, interactions with other medications that affect these neurotransmitter systems are of particular concern. However, the pharmacokinetic profile of solriamfetol is relatively favorable in terms of drug interactions, since it is primarily eliminated renally without significant hepatic metabolism through cytochrome P450 (CYP) enzymes.
Major Interactions
The most important and dangerous drug interaction involves monoamine oxidase inhibitors (MAOIs). Combining Sunosi with an MAOI can cause a severe and potentially fatal hypertensive crisis, because MAOIs prevent the enzymatic breakdown of dopamine and norepinephrine while Sunosi simultaneously prevents their reuptake. This dual mechanism leads to a massive accumulation of these catecholamines, causing extremely high blood pressure, potentially resulting in stroke, organ damage, or death. Sunosi must not be taken concurrently with any MAOI, and a washout period of at least 14 days must be observed between stopping an MAOI and starting Sunosi.
Moderate Interactions
Several categories of medications require caution when used together with Sunosi. Medications that increase blood pressure or heart rate, including sympathomimetic agents, decongestants (such as pseudoephedrine), and certain herbal supplements, may have additive cardiovascular effects when combined with solriamfetol. Blood pressure and heart rate should be monitored more frequently in patients taking these combinations.
Dopaminergic agents such as pramipexole, ropinirole, levodopa, and methylphenidate, which are used in the treatment of Parkinson's disease, restless legs syndrome, depression, and ADHD, may have pharmacodynamic interactions with Sunosi. While these medications can generally be used together under medical supervision, the potential for additive dopaminergic effects should be considered, including increased risk of psychiatric side effects, cardiovascular effects, and potential for dyskinesia.
| Drug/Class | Severity | Effect | Recommendation |
|---|---|---|---|
| MAO Inhibitors (phenelzine, tranylcypromine, selegiline) | Contraindicated | Risk of hypertensive crisis | Do not combine; 14-day washout required |
| Sympathomimetics / Decongestants | Major | Additive increase in blood pressure and heart rate | Monitor BP and HR closely |
| Dopaminergic agents (pramipexole, levodopa, methylphenidate) | Moderate | Additive dopaminergic effects | Use with caution; monitor for psychiatric and CV effects |
| Antihypertensives | Moderate | Solriamfetol may reduce antihypertensive efficacy | Monitor BP; dose adjustment may be needed |
| Other CNS stimulants (modafinil, caffeine) | Minor | Potential additive stimulant effects and insomnia | Be aware of combined stimulant effects |
A notable pharmacokinetic advantage of solriamfetol is that it is not significantly metabolized by CYP enzymes and does not inhibit or induce major CYP isoforms (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, or CYP3A4). This means that traditional drug interactions mediated through CYP enzyme inhibition or induction are unlikely. Approximately 95% of solriamfetol is excreted unchanged in the urine, so renal elimination is the primary route of clearance. Patients with impaired kidney function may require dose adjustments, as reduced renal clearance can lead to higher drug levels.
Tell your doctor or pharmacist about all medications you are taking, including prescription drugs, over-the-counter medications, vitamins, and herbal supplements. Even seemingly harmless substances (such as caffeinated products or nasal decongestants) can interact with Sunosi. Your doctor can help you manage any potential interactions safely.
What Is the Correct Dosage of Sunosi?
Always take Sunosi exactly as your doctor or pharmacist has told you. If you are unsure about any aspect of your dosing regimen, consult your doctor or pharmacist for clarification. The correct dose depends on your underlying condition, your individual response to the medication, and the status of your kidney function.
Adults with Narcolepsy
Narcolepsy Dosing
Treatment typically begins with 75 mg once daily, taken in the morning upon waking. Some patients may start with a dose of 150 mg, depending on the severity of their sleepiness and the clinical judgment of their physician. In certain cases, your doctor may prescribe a lower starting dose of 37.5 mg (obtained by splitting a 75 mg tablet along its score line). After at least 3 days of treatment, your doctor may increase your daily dose to the level that provides the best balance of efficacy and tolerability. The maximum recommended dose is 150 mg per day.
Adults with Obstructive Sleep Apnea
OSA Dosing
Treatment usually begins with 37.5 mg once daily, taken in the morning upon waking. This dose is obtained by splitting a 75 mg tablet along its score line. After at least 3 days, your doctor may increase the dose stepwise based on your response and tolerability. The dose may be increased to 75 mg or up to the maximum recommended dose of 150 mg per day. Remember that Sunosi does not replace your CPAP or other primary OSA therapy.
Elderly Patients (Over 65 Years)
No specific dose adjustment is required for elderly patients based on age alone. However, elderly patients are more likely to have reduced kidney function and should be dosed accordingly (see kidney impairment section below). Additionally, elderly patients may be more sensitive to the cardiovascular effects of solriamfetol, and careful monitoring of blood pressure and heart rate is advisable.
Patients with Kidney Impairment
Because solriamfetol is primarily eliminated by the kidneys (approximately 95% excreted unchanged in urine), patients with impaired kidney function will have higher drug levels and require dose reductions. Your doctor will assess your kidney function before starting Sunosi and adjust your dose accordingly. Sunosi is not recommended for patients with severe kidney impairment (eGFR below 15 mL/min) or end-stage renal disease.
| Kidney Function | eGFR (mL/min) | Maximum Daily Dose |
|---|---|---|
| Normal / Mild impairment | ≥ 60 | 150 mg |
| Moderate impairment | 30 – 59 | 75 mg |
| Severe impairment | 15 – 29 | 37.5 mg |
| End-stage renal disease | < 15 | Not recommended |
How to Take Sunosi
Sunosi tablets should be swallowed whole with water. Take the tablet in the morning when you wake up. You can take Sunosi with food or between meals; food does not significantly affect its absorption. Do not take Sunosi within 9 hours of your planned bedtime, as it may interfere with your ability to fall asleep at night. If you miss your morning dose and there are fewer than 9 hours until bedtime, skip the missed dose and take your next dose the following morning. Do not take a double dose to make up for a forgotten dose.
Continue taking Sunosi for as long as your doctor prescribes. The underlying conditions it treats (narcolepsy and OSA) are chronic disorders, and most patients will need long-term treatment. Do not stop taking Sunosi without consulting your doctor first, even if you feel that your sleepiness has improved.
Missed Dose
If you forget to take Sunosi at your usual time in the morning, you may still take it provided there are more than 9 hours remaining before your planned bedtime. For example, if you usually go to bed at 10:00 PM, you should not take Sunosi after 1:00 PM. If it is too late in the day, simply skip the missed dose and resume your regular dosing schedule the next morning. Never take two doses at once to compensate for a missed dose.
Overdose
In the event of an overdose, contact your doctor or go to the nearest emergency department immediately. Bring this information and any remaining tablets with you. In a reported case of accidental overdose at 900 mg (six times the maximum recommended daily dose), the patient experienced involuntary movements (tardive dyskinesia) and a feeling of restlessness with difficulty staying still (akathisia). These symptoms resolved when Sunosi was discontinued. An overdose may also cause severe elevations in blood pressure and heart rate, which may require urgent medical management.
What Are the Side Effects of Sunosi?
Like all medications, Sunosi can cause side effects, although not everybody experiences them. The side effects observed in clinical trials were generally consistent with the pharmacological action of solriamfetol as a dopamine and norepinephrine reuptake inhibitor. Most side effects were mild to moderate in intensity and were dose-dependent, meaning they were more common and sometimes more pronounced at higher doses. Many side effects, particularly headache and gastrointestinal symptoms, tended to diminish with continued use over the first few weeks of treatment.
It is important to be aware of these potential side effects so that you can report them to your doctor promptly. Some side effects, particularly those related to the cardiovascular system (such as increased blood pressure and heart rate), require ongoing monitoring. Below is a comprehensive overview of the side effects organized by frequency, as observed in clinical studies of Sunosi.
Very Common
May affect more than 1 in 10 people
- Headache
Common
May affect up to 1 in 10 people
- Anxiety
- Insomnia (difficulty sleeping)
- Irritability
- Dizziness
- Nervousness
- Excessive sweating (hyperhidrosis)
- Rapid or irregular heartbeat (palpitations)
- Chest discomfort
- High blood pressure (hypertension)
- Nausea
- Diarrhea
- Stomach pain (abdominal pain)
- Constipation
- Vomiting
- Cough
- Teeth grinding or clenching (bruxism)
- Dry mouth
- Decreased appetite
Uncommon
May affect up to 1 in 100 people
- Agitation
- Restlessness
- Difficulty concentrating
- Tremor (involuntary shaking)
- Increased heart rate significantly above normal (tachycardia)
- Shortness of breath (dyspnea)
- Chest pain
- Thirst
- Weight loss
Frequency Not Known
Reported from post-marketing experience
- Skin rash
- Hives (urticaria)
- Itching (pruritus)
The cardiovascular side effects of Sunosi deserve particular attention. In clinical trials, solriamfetol produced dose-dependent increases in blood pressure. At the 150 mg dose, mean increases in systolic blood pressure of approximately 3 to 5 mmHg and diastolic blood pressure of approximately 1 to 3 mmHg were observed compared with placebo. Heart rate increased by a mean of approximately 1 to 3 beats per minute. While these mean changes may appear modest, some individual patients experienced larger increases. Regular monitoring of blood pressure and heart rate is recommended for all patients taking Sunosi, especially during the initial weeks of treatment and following dose adjustments.
Psychiatric side effects, including anxiety, insomnia, and irritability, are related to the noradrenergic and dopaminergic effects of the medication. These side effects are generally mild to moderate and may improve with continued treatment or dose reduction. Patients with a history of psychiatric disorders should be monitored closely for any worsening of their underlying condition.
If you experience any side effects that are bothersome, persistent, or concerning, contact your doctor. In particular, seek immediate medical attention if you experience severe chest pain, sudden severe headache, signs of an allergic reaction (such as rash, hives, swelling of the face or throat, or difficulty breathing), or any symptoms that suggest a serious cardiovascular event.
It is important to report suspected side effects after a medicine has been authorized. This allows continuous monitoring of the medicine's benefit-risk balance. Healthcare professionals and patients can report suspected adverse reactions to their national medicines regulatory authority (such as the FDA in the United States or the EMA in Europe).
How Should You Store Sunosi?
Proper storage of medications is important to maintain their effectiveness and safety throughout their shelf life. Sunosi should be stored at room temperature, out of the sight and reach of children, in its original packaging to protect it from moisture.
Blister packs: No special storage conditions are required. Store at room temperature in the original blister packaging until use.
Bottles: After first opening, the tablets should be used within 4 months. Keep the bottle tightly closed to protect the tablets from moisture. Solriamfetol is moisture-sensitive, and exposure to humidity can degrade the active ingredient.
Do not use Sunosi after the expiry date printed on the carton, bottle, or blister pack (after "EXP"). The expiry date refers to the last day of that month. Do not dispose of medications via wastewater or household waste. Ask your pharmacist how to properly dispose of medications you no longer use. These measures help protect the environment.
What Does Sunosi Contain?
Understanding the composition of your medication helps you identify it correctly and alerts you to any excipients (inactive ingredients) that you might be allergic or sensitive to. Sunosi is available in two tablet strengths:
- Sunosi 75 mg: Each film-coated tablet contains solriamfetol hydrochloride equivalent to 75 mg of solriamfetol. The tablet is yellow to dark yellow/orange in color, oblong-shaped, with "75" engraved on one side and a score line on the other side. The score line allows the tablet to be divided into two equal halves, each containing 37.5 mg of solriamfetol, which is the starting dose for OSA.
- Sunosi 150 mg: Each film-coated tablet contains solriamfetol hydrochloride equivalent to 150 mg of solriamfetol. The tablet is yellow in color, oblong-shaped, with "150" engraved on one side.
The inactive ingredients (excipients) in Sunosi include:
- Tablet core: Hydroxypropyl cellulose, magnesium stearate
- Film coating: Polyvinyl alcohol, macrogol (polyethylene glycol), talc, titanium dioxide (E171), yellow iron oxide (E172)
If you have known allergies or sensitivities to any of these excipients, inform your doctor or pharmacist before taking Sunosi. Sunosi is available in perforated unit-dose blister packs containing 7, 28, or 56 film-coated tablets, as well as in bottles containing 30 or 100 film-coated tablets. Not all pack sizes may be marketed in your country.
The marketing authorization holder is Pharmanovia A/S, Copenhagen Towers, Ørestads Boulevard 108, 5.tv, DK-2300 Copenhagen, Denmark. The manufacturer is Cilatus Manufacturing Services Limited, Pembroke House, 28-32 Pembroke Street Upper, Dublin 2, Co. Dublin, D02 EK84, Ireland.
Frequently Asked Questions About Sunosi
Sunosi (solriamfetol) and modafinil are both used to treat excessive daytime sleepiness, but they work through different mechanisms. Sunosi is a dual dopamine and norepinephrine reuptake inhibitor (DNRI) that directly blocks the DAT and NET transporters to increase these neurotransmitters in the brain. Modafinil's exact mechanism remains less well understood, though it is thought to primarily affect the dopamine system with weaker effects on other neurotransmitter systems. In terms of clinical differences, Sunosi has a more predictable pharmacological profile because of its well-characterized mechanism of action. Both medications are prescription-only and approved for similar indications, though specific approved indications may vary by country. Your doctor will determine which medication is most appropriate based on your individual clinical situation.
There is no formal contraindication to consuming caffeine while taking Sunosi. However, both caffeine and Sunosi are stimulant-like substances that promote wakefulness, so combining them may lead to additive effects such as increased heart rate, elevated blood pressure, anxiety, nervousness, or difficulty sleeping. If you regularly consume caffeinated beverages (coffee, tea, energy drinks), it may be advisable to moderate your intake when starting Sunosi and pay attention to how the combination affects you. Discuss your caffeine habits with your doctor, particularly if you notice any cardiovascular symptoms or difficulty sleeping.
Solriamfetol reaches peak plasma concentrations approximately 2 hours after oral administration, which is when its wakefulness-promoting effect is typically most pronounced. In clinical trials, improvements in objective wakefulness (as measured by the Maintenance of Wakefulness Test) were observed from the first assessment point. The clinical effect of the medication generally lasts throughout most of the waking day, with a half-life of approximately 7 hours. However, the full benefit of treatment may develop progressively over the first few days to weeks as the body adjusts to the medication. Individual response times may vary.
Sunosi has been classified as a Schedule IV controlled substance in the United States, indicating that while it has some potential for abuse, this potential is considered low relative to Schedule II or III stimulants (such as amphetamine). In human abuse potential studies, supratherapeutic doses of solriamfetol produced some subjective "drug-liking" effects, but these were significantly less than those observed with phentermine (a reference stimulant). In long-term clinical studies, there was no evidence of withdrawal symptoms upon discontinuation. Nevertheless, patients with a history of substance use disorders should be monitored for signs of misuse. Your doctor will consider your individual risk factors when prescribing Sunosi.
Yes, absolutely. Sunosi does not treat the underlying airway obstruction that causes obstructive sleep apnea. It only addresses the residual excessive daytime sleepiness that can persist even when you are using CPAP or other primary OSA therapy adequately. Your CPAP device (or other treatment such as a mandibular advancement device or positional therapy) remains essential for preventing the repeated airway collapses, intermittent oxygen desaturation, and sleep fragmentation that characterize OSA. Stopping CPAP can lead to worsening of your OSA symptoms and may increase the risk of cardiovascular complications associated with untreated sleep apnea. Think of Sunosi as an add-on treatment for daytime alertness, not a replacement for your primary OSA therapy.
Insomnia is a recognized common side effect of Sunosi. If you experience difficulty sleeping at night, there are several strategies to consider. First, ensure that you are taking Sunosi early in the morning upon waking and never within 9 hours of your planned bedtime. Second, practice good sleep hygiene: maintain a regular sleep schedule, create a cool and dark sleep environment, avoid screens before bed, and limit caffeine intake. If insomnia persists despite these measures, contact your doctor. A dose reduction or adjustment in timing may help. Do not take sleep medications without consulting your doctor, as interactions are possible.
References
- European Medicines Agency (EMA). Sunosi (solriamfetol) – Summary of Product Characteristics. Last updated 2025. Available at: www.ema.europa.eu
- U.S. Food and Drug Administration (FDA). Sunosi (solriamfetol) Prescribing Information. Revised 2024. Available at: www.accessdata.fda.gov
- Thorpy MJ, Shapiro C, Mayer G, et al. A randomized study of solriamfetol for excessive sleepiness in narcolepsy. Annals of Neurology. 2019;85(3):359-370. doi:10.1002/ana.25423
- Schweitzer PK, Rosenberg R, Zammit GK, et al. Solriamfetol for excessive sleepiness in obstructive sleep apnea (TONES 3): a randomized controlled trial. American Journal of Respiratory and Critical Care Medicine. 2019;199(11):1421-1431. doi:10.1164/rccm.201806-1100OC
- Malhotra A, Shapiro C, Pepin JL, et al. Long-term study of the safety and maintenance of efficacy of solriamfetol (JZP-110) in the treatment of excessive sleepiness in participants with narcolepsy or obstructive sleep apnea. Sleep. 2020;43(2):zsz220. doi:10.1093/sleep/zsz220
- American Academy of Sleep Medicine (AASM). International Classification of Sleep Disorders, 3rd Edition (ICSD-3-TR). Darien, IL: AASM; 2023.
- Benjafield AV, Ayas NT, Eastwood PR, et al. Estimation of the global prevalence and burden of obstructive sleep apnoea: a literature-based analysis. The Lancet Respiratory Medicine. 2019;7(8):687-698. doi:10.1016/S2213-2600(19)30198-5
- Bassetti CLA, Adamantidis A, Burdakov D, et al. Narcolepsy — clinical spectrum, aetiopathophysiology, diagnosis and treatment. Nature Reviews Neurology. 2019;15(9):519-539. doi:10.1038/s41582-019-0226-9
- World Health Organization (WHO). WHO Model List of Essential Medicines, 23rd List. Geneva: WHO; 2023.
- British National Formulary (BNF). Solriamfetol. NICE Evidence Services. 2025. Available at: bnf.nice.org.uk
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This article was medically reviewed on . iMedic follows strict editorial guidelines to ensure medical accuracy. All claims are supported by peer-reviewed research and verified against official regulatory documentation from the EMA, FDA, and international sleep medicine societies.