Table of Contents
- 1 Attention Deficit Hyperactivity Disorder (ADHD)
- 2 Treatment of ADHD
- 3 ADHD and Vyvanse
- 4 Adverse effect profile of Vyvanse
- 5 Why does Vyvanse cause changes in sexuality?
- 6 Changes in the sexual drive during Vyvanse therapy
- 7 Management of the sexual side effects of Vyvanse
- 8 Management of ADHD with Vyvanse; efficacy and cost-effectivity
- 9 Conclusion
Attention deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental disorder in childhood and adolescence proposed to affect between 2.2 to 17.8% of school-aged children and adolescents. It is characterized by a wide range of deficits ranging from learning limitations to the control of executive functions as well as generalized impairment in social skills. Generally, this condition is commoner in boys than in girls and can affect adults with a worldwide adult prevalence rate of 2.8%.
Attention Deficit Hyperactivity Disorder (ADHD)
The spectrum of ADHD can be divided into three; the predominantly inattentive type, the predominantly hyperactive-impulsive type, and the combined type depending on the most pronounced feature in the person with a proposed prevalence of2.95%, 2.77%, and 2.44% respectively.
In addition to the above, data from the CDC from data in a national 2016 parent survey, an estimated 6.1 million children have been diagnosed with ADHD with over 5.7 million of them aged between 6 and 17 years.
Many children with ADHD also have other comorbid conditions that trail the diagnosis. In the survey above, the CDC posits that about 6 in 10 children with a diagnosis of ADHD had in addition, at least one emotional, behavioral, or mental disorder. These disorders include conduct problems, anxiety, autism spectrum disorder, depression, and Tourette syndrome.
Although the exact pathogenesis of ADHD has not been elucidated, several studies suggest that it may result from neurotransmitter (dopamine and noradrenalin) dysregulation in the brain, structural alteration in certain brain areas, and neurophysiological deficits and abnormalities in cognitive function. The theory of neurotransmitter dysregulation holds sway in current times owing to the significant benefits from the use of psychostimulants in its management.
Treatment of ADHD
Two major treatment modalities are utilized in the management of ADHD. These include the use of medications that target the neurotransmitter system as stated above and behavioral therapy. According to the American Academy of Pediatrics (AAP), it is recommended that children 6 years and above be managed with both treatment modalities while those younger than 6 years should have behavioral therapy as their first-line treatment protocol. Currently, data from a national parent survey in 2016 found that about 62% of children aged between 2 -17 years with a diagnosis of ADHD were on medication and 47% on behavioral therapy.
The medications available for this treatment belong to the class of pharmacologic agents referred to as psychostimulants. This is because, they act by increasing the level of stimulatory neurotransmitters – dopamine and norepinephrine, in the brain.
ADHD and Vyvanse
Vyvanse, containing the active ingredient, Lisdexamfetamine, is a schedule II stimulant medication. It has found beneficial applications in the treatment of ADHD and binge-eating disorder (BED) and is quite preferable by many to methylphenidate. The FDA licensed this drug for use in adults in 2008 and has since then, found wide use in this regard. Over 80% of people who use this medication record improvement in their symptoms of ADHD.
Lisdexamfetamine is an inactive prodrug that when taken, is metabolized into dextroamphetamine, a pharmacologically potent psychostimulant that is responsible for the effect of Vyvanse. The dextroamphetamine acts by causing the release from storage sites as well as preventing the reuptake of neurotransmitters from the presynaptic neurons. This ensures continued neuronal firing from continued stimulation by hormones accumulating in the synaptic cleft which is responsible for the alleviation of the symptoms of ADHD.
Adverse effect profile of Vyvanse
The side effect profile of this drug is similar to that of amphetamines. These adverse effects as observed in clinical trials include insomnia, dry mouth, vomiting, anxiety, irritability, weight loss, constipation, upper abdominal pain, decreased appetite, dizziness, etc. Rare but serious side effects include stimulant psychosis, serotonin syndrome (especially when taken with Monoamine Oxidase Inhibitors), sudden cardiac death especially in those with underlying cardiac conditions, and mania.
In addition to the above, a very important adverse effect of Vyvanse is sexual dysfunction. However, not every user of this medication reports it and it is commonly reported in older patients. Being an amphetamine, Vyvanse shares changes in libido and sexual function as a common side effect with other drugs of this class. This sexual dysfunction can be an increase in libido and sexuality (hyper-sexuality) or a decrease in sexual arousal.
Why does Vyvanse cause changes in sexuality?
The effect of this drug on sexual arousal stems from its effects on the neuro-hormones, dopamine, and serotonin. According to several studies, Dopamine is associated with increased sexual arousal while increasing serotonin tends to dampen sexual arousal. Since Vyvanse increases the levels of these two substances in the brain, it is understandable why there may be sexual side effects and the effect observed will depend on which of the substances above is more elevated than the other. On the above note, one would agree that the effects are variable which explains why there are varying reports on the sexual side effect of the drug.
Changes in the sexual drive during Vyvanse therapy
The changes in sexuality during this drug treatment can be in the context of behavior or desire and these effects are very infrequent as they are not listed in the side effect profile of the drug as filed with the FDA.
It is important to note, however, that the change in sexual behavior may be a therapeutic benefit of the drug. For instance, in a patient with untreated ADHD who is hypersexual and masturbates a lot, starting Lesdexamfetamine therapy may record a reduction in sexual desire which may be misconstrued as a negative effect while in reality, it returned the patient’s sexual drive to normal levels. Below, we will discuss the specific side effects observable in males and females.
Side effects of Vyvanse in males
In addition to the changes in sexual desire and libido, Vyvanse has been shown to also cause Erectile dysfunction owing to the effects of the amphetamine on peripheral blood circulation.
Erectile dysfunction is the inability of a male to achieve an erection or maintain one of sufficient rigidity and duration to achieve sexual gratification which has been present for a minimum of 6 months. To achieve an erection, blood flows into the Corpora Carvenosa (spongy muscles) of the penis due to the vasodilation of the helicine arteries (end arteries supplying blood to the penile shaft). Vyvanse causes erectile dysfunction by causing vasoconstriction of these arteries
Side effects of Vyvanse in Females
The effect of this drug on the female population is a lot more obscure. They include diminished or lack of sexual desire, diminished arousal, difficulty in achieving orgasm, and dyspareunia (painful sexual intercourse).
Also, according to a study at the University of Maryland Baltimore School of Medicine, the use and abuse of amphetamines by females is associated with a dramatically increased sexual drive which resulted in risky sexual behaviors.
Vyvanse induced hypersexuality
This refers to increased sexual behavior that cannot be explained by anything except as a side effect of Vyvanse therapy that is characterized by elevated sexual desire, increased masturbation, as well as an intrusive and time-consuming preoccupation with sexual fantasies and thoughts. It is believed to result from the interaction between the amphetamine and the sex hormones that mediate sexual behaviors. This interaction will result in changes in key nuclei in the brain that causes the preoccupation with sex and sexual events.
Management of the sexual side effects of Vyvanse
Several approaches can be adopted in the management of these side effects based on the discretion of the prescribing physician.
The first is “watchful waiting” which involves observing the condition to see if the body will adapt to the drug over time and do away with the side effects.
Another practical approach to the management is to reduce the dose of the drug. On average, the drug is administered at a dose of 30mg daily. In the setting of sexual dysfunction, the dose of the drug can be stepped down to as little as 10mg and increased as required.
The last but most drastic is to switch the person to another drug. This is reserved for people in whom the adverse effects have become intolerable and in whom there is an increased risk of discomforting withdrawal symptoms.
Management of ADHD with Vyvanse; efficacy and cost-effectivity
Although several drugs are available for the treatment of ADHD, it is important to note that Vyvanse has shown significant effectiveness in the resolution of symptoms of ADHD. Multiple clinical trials have shown consistent findings that posit that the drug is very effective in the treatment of the condition. About 80% of adults who received Vyvanse therapy recorded resolution in symptoms within 1.5 hours of starting therapy.
In the context of cost-effectivity, a study conducted by Evelina Zimovetz et al compared the cost-effectiveness of Lisdexamfetamine as a first-line treatment for adults with ADHD compared to Methylphenidate extended-release and Atomoxetin and showed that it reduces the per-patient annual cost by £5 and £200 and increasing mean quality-adjusted life years by 0.005 and 0.009 respectively. These findings show that Vyvanse provides cost-effective treatment for adults with ADHD.
On the above note, despite the side effect profile which is common to all the drugs treating ADHD, it is a good choice of medication in the context of efficacy and cost-effectivity. In addition to this, a savings program is available that offsets some of the cost of this medication.
ADHD, a common neurodevelopmental disorder can be managed with Vyvanse, a highly efficacious and cost-effective psychostimulant drug. Although some persons report sexual dysfunction as a side effect, this can be effectively managed with watchful waiting, dose reduction, or drug switching as a last resort.