Modafinil Dependence and Hypersexuality: A Case Report and Review of the Evidence

Modafinil Induced Spontaneous Ejaculation Without Orgasm: A Case Report

ABSTRACT

Modafinil is used for the treatment of narcolepsy and obstructive sleep apnea syndrome, and as add-on therapy for psychiatric diseases such as attention-deficit/hyperactivity disorder, schizophrenia, depression, cocaine addiction. The exact mechanism of action is unknown. Modafinil may be helpful for the treatment of erectile dysfunction and premature ejaculation. The addition of modafinil to antidepressant treatment may provide positive effects on sexual dysfunction. However, side effects such as hypersexuality and unwanted orgasm have been reported with modafinil treatment. In this article, a patient who had developed spontaneous ejaculations after the addition of modafinil for the treatment of depression with venlafaxine is discussed. Although venlafaxine treatment continued after the discontinuation of modafinil, spontaneous ejaculation did not continue. It should be kept in mind that agents with dopaminergic and noradrenergic effects, such as modafinil, can cause undesirable sexual side effects.

Pharmacokinetic and pharmacodynamic of the cognitive enhancer modafinil: Relevant clinical and forensic aspects

Modafinil is a nonamphetamine nootropic drug with an increasingly therapeutic interest due to its different sites of action and behavioral effects in comparison to cocaine or amphetamine. A review of modafinil (and of its prodrug adrafinil and its R-enantiomer armodafinil) chemical, pharmacokinetic, pharmacodynamic, toxicological, clinical and forensic aspects was performed, aiming to better understand possible health problems associated to its unconscious and unruled use. Modafinil is a racemate metabolized mainly in the liver into its inactive acid and sulfone metabolites, which undergo primarily renal excretion. Although not fully clarified, major effects seem to be associated to inhibition of dopamine reuptake and modulation of several other neurochemical pathways, namely noradrenergic, serotoninergic, orexinergic, histaminergic, glutamatergic and GABAergic. Due its wake-promoting effects, modafinil is used for the treatment of daily sleepiness associated to narcolepsy, obstructive sleep apnea and shift work sleep disorder. Its psychotropic and cognitive effects are also attractive in several other pathologies and conditions that affect sleep structure, induce fatigue and lethargy, and impair cognitive abilities. Additionally, in health subjects, including students, modafinil is being used off-label to overcome sleepiness, increase concentration and improve cognitive potential. The most common adverse effects associated to modafinil intake are headache, insomnia, anxiety, diarrhea, dry mouth and raise in blood pressure and heart rate. Infrequently, severe dermatologic effects in children, including maculopapular and morbilliform rash, erythema multiforme and Stevens-Johnson Syndrome have been reported. Intoxication and dependence associated to modafinil are uncommon. Further research on effects and health implications of modafinil and its analogs is steel needed to create evidence-based policies.

The Availability of Modafinil and Methylphenidate Purchased from the Internet in the United Kingdom Without a Prescription

Background: There are reports of prescription stimulants being purchased online for use as cognitive enhancers or "smart drugs." Objectives: The aim of this study was to investigate availability of modafinil and methylphenidate from internet suppliers from the perspective of a typical United Kingdom (UK) based customer. Methods: Using European Monitoring Center for Drugs and Drug Addiction (EMCDDA) internet snapshot methodology, we undertook an English language internet snapshot survey in July-August 2018 to gather information on the availability and price of modafinil and methylphenidate from online retailers. Results: A total of 55 modafinil and 14 methylphenidate websites were identified from which the drug could be purchased without a prescription. Minimum purchase quantities ranged from 10 to 90 tablets for modafinil and 1-1,005 tablets for methylphenidate with no apparent upper limit to the number that could be purchased. The price per tablet varied from £0.38-5.31 for modafinil and £0.16-5.70 for methylphenidate. Free shipping was offered if more than a certain amount was spent on 46 (83.6%) modafinil and 7 (50.0%) methylphenidate websites and discounts were offered on 43 (78.2%) modafinil and 4 (28.6%) methylphenidate websites. Conclusions: Modafinil and methylphenidate are widely available to purchase via internet from the UK without a prescription. The pricing on websites encourages users to buy greater quantities to qualify for discounts and free shipping. The quantities available suggest these purchases may be used in greater amounts than would be legitimately prescribed, increasing the risk of misuse or diversion to other individuals.

Participation of Dopamine D1 and D2 Receptors in the Rapid-Onset Behavioral Sensitization to Modafinil

Studies on the abuse potential of modafinil, a psychostimulant-like drug used to treat narcolepsy, are still controversial. While some studies claim no potential for abuse, increasing evidence suggests that modafinil induces abuse-related effects, including rapid-onset behavioral sensitization (i.e., a type of sensitization that develops within hours from the drug priming administration). The rapid-onset sensitization paradigm is a valuable tool to study the neuroplastic changes that occur quickly after drug administration, and shares neuroadaptations with drug abuse in humans. However, the mechanisms involved in the rapid-onset behavioral sensitization induced by modafinil are uncertain. Our aim was to investigate the possible involvement of dopamine D1 and D2 receptors on acute modafinil-induced hyperlocomotion and on the induction and expression of rapid-onset behavioral sensitization induced by modafinil in male Swiss mice. Treatment with the D1 receptor antagonist SCH 23390 or the D2 receptor antagonist sulpiride attenuated the acute modafinil-induced hyperlocomotion in a dose-dependent manner. Pretreatment with either antagonist before the priming injection of modafinil prevented the development of sensitization in response to a modafinil challenge 4 h later. However, only SCH 23390 decreased the expression of modafinil-induced rapid-onset behavioral sensitization. Taken together, the present findings provide evidence of the participation of D1 and D2 receptors on the development of rapid-onset behavioral sensitization to modafinil, and point to a prominent role of D1 receptors on the expression of this phenomenon.

Transsexualism: A Different Viewpoint to Brain Changes

Transsexualism refers to a condition or belief which results in gender dysphoria in individuals and makes them insist that their biological gender is different from their psychological and experienced gender. Although the etiology of gender dysphoria (or transsexualism) is still unknown, different neuroimaging studies show that structural and functional changes of the brain result from this sexual incongruence. The question here is whether these reported changes form part of the etiology of transsexualism or themselves result from transsexualism culture, behaviors and lifestyle. Responding to this question can be more precise by consideration of cultural neuroscience concepts, particularly the culture–behavior–brain (CBB) loop model and the interactions between behavior, culture and brain. In this article, we first review the studies on the brain of transgender people and then we will discuss the validity of this claim based on the CBB loop model. In summary, transgender individuals experience change in lifestyle, context of beliefs and concepts and, as a result, their culture and behaviors. Given the close relationship and interaction between culture, behavior and brain, the individual’s brain adapts itself to the new condition (culture) and concepts and starts to alter its function and structure.