Shelly asked
I am a 35 year old female diagnosed with ADHD. I started on Adderall xr 20mgs 2x daily, then moved to 30 mg x2 daily because the 20 mg was not enough, 30 mg was too much. Three days ago my psychiatrist switched me to 30 mg of Vyvanse. I have no motivation, feeling a little depressed, want to sleep all the time, stomach pains a few hours after taking and nauseous. It doesn't matter if I eat or not. Is this normal? Will they subside soon or should I call my doctor about them?
Answer
The side effects you are experiencing from Vyvanse are not particularly common, but have been reported in certain individuals. There is a chance the dose you are taking isn't therapeutically high enough, or, less commonly, the dose may be too high. Often times, doses that are too high work for short period of time, but can then cause depression, fatigue and nausea as the dose wears off.
You could also simply be having an issue where you are not responding to the different active ingredients in Vyvanse. Switching stimulant medications can be difficult, especially if you have been on one agent for a long period of time. Studies have reported a variety of problems when switching agents including:
- Less therapeutic benefit from the new agent
- Increased side effects
- Lower potency of new agents
There are a lot of factors to consider when evaluating your new dose and therapy. You should absolutely report the symptoms you are experiencing to you doctor so adjustments can be made.
Adderall Vs. Vyvanse: Differences
Adderall XR
Adderall is a combination of amphetamine salts and contains:
- Amphetamine Aspartate
- Amphetamine Sulfate
- Dextroamphetamine Saccharate
- Dextroamphetamine Sulfate
The combination of stimulants ingredients in Adderall in a contributing factor to it's effectiveness. Variability in response to Adderall among individuals is an lessened due to the combination of active ingredients.
Having said that, certain genetic differences (i.e. polymorphisms in metabolizing enzymes) in individuals can result in significant variability among patients, especially when it comes to how well the drug is absorbed/metabolized. Variations in body conditions as well (e.g stomach acidity, GI motility) can cause significant differences in how much Adderall is absorbed. Generally however, peak concentrations occur in about 7 to 10 hours in adolescents and about 8 hours in adults.
Vyvanse
Vyvanse contains lisdexamfetamine and is considered to be a "prodrug", meaning that it needs to be converted in the body to its active form. Lisdexamphetamine converts to dextroamphetamine (one of the ingredients in Adderall XR) and L-lysine in the body, primarily in the blood.
Vyvanse is considered to provide more consistent dosing (i.e. less variability) than Adderall as differences in body chemistry don't affect Vyvanse as much. Vyvanse is mostly converted to dextroamphetamine in the blood, and changes to the drug in the GI tract are minimal, unlike for Adderall. In addition, it doesn't appear to be greatly affected by certain metabolizing enzymes in the liver, unlike Adderall.
In addition, maximum concentrations of Vyvanse are seen in about 4-5 hours with Vyvanse, making it faster acting than Adderall.
Summary
Aside from the differences in metabolism of these drugs, the main differentiating point is the difference in ingredients. You should certainly talk to your doctor regarding the symptoms you are having as a dose adjustment or drug change seems prudent. If your doctor wishes to increase you on Vyvanse, know that that is a common occurrence. Vyvanse is generally initiated at a dose of 20-30 mg and increases may be made in increments of 10 to 20 mg per week until an effective dose is reached.
