One Dose Of Adderall XR Not Lasting Long Enough

In our latest question and answer, the pharmacist discusses options to consider if Adderall XR is not lasting long enough for you.

Question

I've been taking 10 mg XR Adderall once a day for about a month. It seems to be wearing off too soon, should I ask my doctor to prescribe me a higher milligram? Or should I ask her for 2 a day? Or ask her for the IR Adderall in a higher milligram? Thanks for any feedback.

Asked by Tiff On Nov 15, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Nov 16, 2022
Last updated Mar 29, 2024

Key points

  • Adderall XR is FDA-approved for once-daily dosing. Dosing it twice a day is uncommon due to the increased risk of side effects, such as insomnia.
  • Increasing your Adderall XR dose to a higher strength will generally not make it last longer per dose based on how the drug is metabolized.
  • If one dose of Adderall XR isn't lasting long enough, options include adding on a 'booster' immediate-release Adderall dose in the afternoon or trying other CNS stimulants.
  • An alternative drug option is Mydayis, an extended-release amphetamine; dextroamphetamine combination drug that is designed to last around 16 hours per dose.

Answer

Adderall XR (Amphetamine; Dextroamphetamine extended-release capsules) is only FDA-approved for once-daily dosing. However, while uncommon, it can be to be dosed twice daily in some individuals, but this increases the risk of side effects, like insomnia, so it isn't done very often.

Many times, there are alternatives to taking Adderall XR twice a day that may be better tolerated.

CNS (central nervous stimulants), like Adderall XR, can often be a challenge to prescribe as the clinical response can vary widely by individual. A drug not lasting long enough is a common concern that comes up for some individuals.

It is therefore important to individualize the dosage, and/or drug, according to the therapeutic needs and response of the person taking it.

In the next sections, I discuss Adderall XR and some options for you if you're finding it does not last long enough.

How Long Does Adderall XR Usually Last Per Dose?

Adderall XR generally lasts 8 to 12 hours per dose, although this can vary by individual.

In fact, Adderall XR was designed to mimic the twice-daily dosing of Adderall (immediate-release). For example, Adderall XR 20mg is equivalent to Adderall 10mg taken twice daily (with each dose separated by four hours).

This is illustrated in the below graph showing plasma concentrations over time for both Adderall XR 20mg and Adderall 10mg (two doses separated by four hours).

Adderall Concentration Over Time

You'll notice in the above graph that peak concentrations of Adderall XR occur 7 hours after dosing. After this time, it gradually starts to lose effect.

Does Increasing Your Dose Of Adderall XR Make It Last Longer?

It is important to note that increasing your dose (i.e., taking a higher milligram strength) of Adderall XR will generally not make it last longer per dose.

While increasing your dosage will produce higher blood concentrations of the drug, based on how the drug (and most drugs) are metabolized, taking more won't make it last longer. Just like if you took one tablet of Tylenol or two, it still lasts around the same amount of time.

I won't get into the nitty-gritty of pharmacokinetics and drug elimination, but most drugs follow what is known as 'first-order kinetics', where the rate of elimination is proportional to the drug concentration. In other words, the higher the drug concentration, the higher its elimination rate.

So, if you take a higher strength of Adderall XR, your body will just metabolize and eliminate it more quickly. All strengths of Adderall XR are metabolized and eliminated in essentially the same amount of time.

What To Do If One Dose Of Adderall XR Doesn't Last Long Enough

You have a number of options if you find your morning dose of Adderall XR isn't lasting long enough.

As mentioned, simply increasing your dose will likely not make it last longer. Additionally, I have seen Adderall XR dosed twice a day, but it's not common. Taking an afternoon dose will greatly increase your risk of problems sleeping at night.

More commonly, an immediate-release Adderall is prescribed for afternoon use as a 'booster' dose.

Immediate-release Adderall lasts around four to six hours per dose, so taking it in the afternoon as your Adderall XR wears off can provide you with symptom relief and will be far less likely to cause you trouble sleeping at night versus taking a second dose of Adderall XR in the afternoon.

Your other options include trying other long-acting stimulants, of which there are many. They include:

  • Concerta (methylphenidate extended-release)
  • Daytrana patch (methylphenidate extended-release)
  • Focalin XR (dexmethylphenidate extended-release)
  • Vyvanse (lisdexamfetamine)
  • Mydayis (amphetamine; dextroamphetamine extended-release)

In my opinion, the closest options to what you are taking now would be adding on an immediate-release Adderall for afternoon dosing or trying Mydayis.

Mydayis contains the same drugs as Adderall XR (amphetamine; dextroamphetamine) but is designed to last longer than Adderall XR.

In fact, Mydayis capsules contain three drug delivery beads, releasing medication immediately, mid-day, and in the afternoon. It lasts around 16 hours per dose (compared to around 8-12 for Adderall XR).

Be sure to talk to your doctor about how Adderall XR is working for you. I would imagine they have seen cases like yours before and you can work together to find a solution that best meets your needs.

Final Words

Thanks for your question! I hope this helped!

References

  • Adderall XR Prescribing Information, AccessFDA
  • Amphetamine Monograph, PubChem
  • Dextroamphetamine-Amphetamine, NIH
  • Metabolism, distribution and elimination of lisdexamfetamine dimesylate: open-label, single-centre, phase I study in healthy adult volunteers, PubMed
  • Pharmacokinetics and Pharmacodynamics of Lisdexamfetamine Compared with d-Amphetamine in Healthy Subjects, PubMed
  • Long-acting stimulants: development and dosing, PubMed
  • Mydayis Prescribing Information, AccessFDA

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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