Amphetamine-type stimulants in Latin American Medicine Students. A review.

INTRODUCTION

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p class="Basic-Paragraph para-style-override-8">INTRODUCTION

 

Data from 2017 indicate that 5.5% of the world population between 15 and 64 years of age (271,000,000 inhabitants) had used drugs in the last year. Between 2009 and 2016, drug use increased by 30%(1), with men reporting the highest consumption(2), particularly during the period at university(2), due to the ease of access to certain drugs.(3)

 

In Latin America, young people between 18 and 24 years old, especially university students, have the highest frequency of both legal and illegal substance use(4). Various studies show that the most widely used drugs in this population are alcohol, tobacco, cannabis, inhalants and stimulants.(1,3,5)

 

Among stimulants, amphetamine-type drugs are the most widely used synthetic drugs worldwide.(6)

 

Amphetamine-type stimulants (ATS) are substances with a substituted phenylethylamine structure, which include amphetamine, dextroamphetamine and metamphetamine. Also included are substances that are structurally different but have similar effects, such as methylphenidate.(7)

 

ATS increase mental acuteness, alertness, and vigor, as well as being anorexigenic(9) . They are available by prescription for a variety of disorders(7,10). However, the prescription of these medications is “subject to control of psychotropics” due to the potential risk of abuse and dependence.(11).

 

The most widely used stimulants include methylphenidate (Concerta ® and Ritalin ®) and amphetamines (Adderall ® and Dexedrine ®).(9)

 

The non-medical use of ATS has been described mainly among university students, due to the search for a probable cognitive benefit.(11-14). The population of medical students (MS) has peculiarities that make it particularly susceptible to the consumption of ATS. In general, MS are subject to high academic demands, increasing each year due to applications for subspecialities (11), that can cause stress, anxiety and affective disorders, all of which are known risk factors for psychotropic drug use.(15,16). In addition, medical students have easy access to these drugs.(17)

 

The general objective of this study was to review the information available on the use of ATS among MS in Latin America. The specific objectives were to:

1. Establish the frequency of their use by MS.

2. Explore the available evidence concerning:

a. Motivation for their use by MS.

b. Possible risk factors and protective factors in their use by MS

c.- Consequences for academic performance; adverse effects of ingestion and consequences of long-term use by MS.

d.- Management and prevention of ATS use by MS.

e.- Comparison of ATS use between MS and students in other university disciplines.

MATERIALS AND METHODS

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Initially, a systematic review was carried out with the following MeSH terms: “amphetamines”, “methylphenidate”, “stimulants”, “psychotropic drugs”, “medical students” and free term data “psychoactive”, “adderall”, “ritalin”, “lisdexamfetamine”. associated with “medical students” in PubMed. In total 1,260 articles were found. In addition, a search was carried out in SciELO, where 57 publications were found; likewise in LILACS, where 122 more works were found using the same MeSH terms in English, Spanish and Portuguese.

 

In total, 1,439 articles were located. From reading the abstracts of these articles, works that met the following inclusion criteria were selected: a) the language was Spanish, English or Portuguese; b) the population studied was medical students in Latin America; c) the articles were original studies and not literature reviews or meta-analyses. Finally, 45 articles were selected for reading in full, for which there was access to the complete text. A detailed reading of these articles was carried out. Twenty-seven articles were discarded because they were studies that did not include the use of ATS among medical students. Thus, 18 articles were finally selected for review.

RESULTS

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Of the 18 articles selected for review, 14 refer to South American countries (7 to Brazil, 4 to Colombia, 1 to Paraguay, 1 to Chile, 1 to Argentina), 2 to Central American countries (2 to Honduras), 2 to Caribbean countries (1 to Cuba and 1 to Puerto Rico). The articles, the type and size of sample, and experimental design are summarized in Table 1.

 

The studies reviewed show a trend towards high consumption of ATS (despite the fact that some studies do not specifically state whether the drugs in question are ATS or other types of stimulants).

 

Of the 18 selected studies, 3 describe the frequency with which ATS are used by MS, i.e.: 31,67%(19), 42,3%(20) y 47,4%(21), without specifying if their use is with or without a medical prescription.

 

Four studies distinguished between the use of methylphenidate with and without medical prescription, with the following results: 11% versus 23.02%(22), 12% versus 33%(23), 7% versus 11.2%(24), respectively. Martins et al.(25) estimated the frequency of methylphenidate consumption at 2.16% of MS, of whom 10.2% had a medical prescription. Romero et al.(17), only mentioned those without any medical intervention, estimating consumption at 2.1%. The study by Petroianu et al.(26), showed a frequency of 7.5% for the use of stimulants, and that of Buchanan et al.(18), of 3.2% for the use of psychotropic drugs. The specific frequency of ATS use was not specified in any of these studies.

 

On the other hand, 3 articles describe frequency according to the temporality of consumption. Boniatti et al.(27) found that the lifetime frequency of amphetamine use was 12.6%, 7.1% in the last 12 months, and 4.9% in the last 30 days. Garcia de Oliveira et al.(28) describe two independent cross-sectional studies, 5 years apart, to quantify drug use in MS. The results showed that the lifetime frequency of amphetamine use was 4.4% (95% CI=2.1-6.6), 3.2% over the last 12 months (CI 95%=1.2-5.1) and 3.2% in the last 30 days (95% CI=1.2-5.1). In the second study, the frequency of consumption through life was 9.5% (95% CI= 5.8-13.2), in the last 12 months, 7.6% (95% CI =4.3-10.9) and in the last 30 days, 5.2% (95% CI=2.4-8.0). The studies were considered independent samples, so no statistical analysis was performed between them. Baron et al.(29), reported that 51.5% of MS consumed some type of stimulant during their university career. The drug most commonly used was methylphenidate, at 35% of all ATS.

 

We found 3 studies dealing with Health Sciences students, who include MS. According to the study by Licona et al.(30), 29% of Health Sciences students used some type of drug and only 1.25% of them used amphetamines. Lucas et al.(31) reported that, among university students in the health area, the lifetime frequency of (illicit) amphetamine use was 9.2% (95% CI=7.12-11.28). Of these, 61.8% (95% CI= 8.13-75.4) began using when they were over 18 years of age. Martinez et al.(32), observed that 5.2% of health science students had used methylphenidate in the previous year. A study conducted by Gálvez et al.(33) observed no report of the active use of amphetamines in the group of MS interviewed.

 

Of the articles reviewed, 7 indicated the reasons for use by MS(22-22,24,27-29). Six of them state that the main reason for taking ATS was to improve academic performance(20-22,24,27,29). The other reasons reported were “experimental” use(22,24), “fun”(22,24,27), “to stay awake”(22), “to relieve stress”(28), and “for socializing”.(27)

 

Seven of the studies reviewed covered the relationship between the use of amphetamines in MS and gender.(17,21,22,26-28,31). In 2 of the studies, statistical analyses showed that the consumption of amphetamines tends to be higher in men than in women (Petroianu et al. (p <0.001).(24), and in Lucas et al. (p =0.059)(31). In the studies by Romero et al.(17), and Boniatti et al(27), frequency of ATS use was found to be higher in men than in women (1.4% versus 0.7% and 12.6% versus 16.3% respectively, statistical analysis not presented). In 3 studies, no significant difference was found.(21,22,28)

 

Five articles analyzed the association between the semester studied and ATS use among MS. In the study by Barón et al.(29), a significant relationship was found between semester and amphetamine use (p=0.02), in that usage increased in the later semesters. Use of methylphenidate was also described as showing significant dependence (p=0.014) on the semester studied (greater consumption in the later semesters). In addition, participants were asked directly if they had used amphetamines to improve academic performance. The response depended significantly on the semester studied, clearly showing greater use in the later semesters, especially during the fourth academic semester (p=0.008). In the study by Silveira et al.(22), the number of sixth-year students who had used methylphenidate was more than double (46.05%) that of fifth-year students (22.76%) (p=0.004). Likewise, Acevedo et al.(31) and Martins et al.(20) found a significant dependence on the level reached in studies, in that the more advanced the semester, the greater the use of amphetamines (p=0.026 and p?0.0001 respectively). Oliveira et al(23), on the other hand, observed a higher percentage of methylphenidate consumption in the first and second year (21% and 32% respectively), than in the third, fourth and fifth year (18%, 14% and 14% respectively).

 

Of the articles included, two analyzed the relationship between the use of amphetamines among Health Sciences students and by socioeconomic level, without providing differentiated information on medical students (30,31). Licona et al.(30) found that while 29% of medical, nursing and dentistry students used some type of psychoactive substance, only 1.24% of them used amphetamines and they belonged to the group with the highest monthly income of >16,000 lempiras (approx. >USD 640.13). Similar results were reported by Lucas et al.(31), who found that students from the medicine, dentistry and pharmacy disciplines belonging to socioeconomic level A (the highest socioeconomic level) had a higher proportion of lifetime amphetamine use at 11.9% (CI 95 %=3.98-19.82), compared to level B 9.16% (95% CI= 2.11-16.21), level C 1.39% (95% CI= 0.00-4.25). Levels D and E did not report use of amphetamines (p=0.020).

 

Four of the studies included the variable “university entrance” as a factor in the initiation of ATS use by MS (18,22,28,29). Of these, 3 articles detail the increase in consumption after university entrance, without carrying out a statistical analysis. Among the results observed, Barón et al.(29) found that 51.5% of the MS used amphetamines and of these, 87.9% reported that they had not used them prior to entering the academic program. Likewise, Silveira et al.(22) found that 82.8% of MS who used methylphenidate for non-medical reasons started using it at university. Boniatti et al.(27), showed that 78.3% of the MS who used amphetamines had started taking them during their academic life. Buchanan et al.(18), found that after entering the university, 1.15% started on amphetamines specifically and 12.3% on popular

stimulants.

 

Of the studies reviewed, three described the relationship between protective factors and the use of amphetamines (and other drugs) by MS(27,29,31). In the study carried out by Barón et al.(29), in the group of MS who take amphetamines, 72% report having some religious belief, while in the group of non-consumers, the frequency of believers increases significantly to 82.8% (p=0.063), suggesting “religious belief” as a protective factor. In the study by Boniatti et al.(27), activities such as “going out with the family”, “playing sports” and “going to church” (p<0.05) are considered protective factors against use of psychotropic drugs.

 

Finally, the work of Lucas et al.(31) showed that the perception of medicine, dentistry and pharmacy students regarding the use of non-prescription medications (anxiolytics and amphetamines) is generally negative: 55% consider it very bad for health, 37.6% consider it bad, while only 2.3% consider it not to be harmful.

 

Regarding side effects, two studies reported side effects of methylphenidate use. Oliveira et al.(23), found that 35% of users presented tachycardia, 18% loss of appetite, 23% hand tremors, 12% xerostomia, and 47% reported other side effects not described in this article. Moreover, this was the only study of those selected that reported that 24% of MS users of methylphenidate stated that they increased the dose to obtain the same effect (i.e. increased ability to concentrate) as when they started taking it. For their part, Martins et al.(25), found 85.71% of adverse effects. Those most frequently experienced were anxiety 38.29%, insomnia 38.12% and palpitations 35.38%. Others were diarrhoea, headache, tremor, drowsiness, polyuria, abdominal pain, nausea, vomiting, sweating, anorexia, and

constipation.

 

Among the articles selected, no studies were found on the long-term consequences of the use by MS of amphetamines and their derivatives, nor were any studies found that described and/or analyzed the management and prevention of ATS use in this population.

 

Finally, comparing other university courses, 3 studies describe drug use in general (which includes ATS), and one study describes the specific use of amphetamines in various university courses that include Medicine (the results are mainly descriptive). Castano et al.(19), noted significantly greater substance use (p= 0.011) by students of Law, with a frequency of 45.8%, followed by Economics (with 40.74%), and in third place Medicine (with 31.67%). On the other hand, Licona et al.(30) found that, of drug-using students, 62% were from Medicine, 24% from Dentistry and 14% from Nursing. This is similar to the findings of Acevedo et al.(20) who observed amphetamine use to be higher in MS at 42.3%, followed by Economics at 16.7%, Business Administration at 14.3%, and Law

at 12.2%.

DISCUSSION

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To our knowledge, this is the first literature review on ATS use among MS in Latin America. The most recent worldwide review was published in 2013. It found use of methylphenidate among MS to be widespread, with its main objective being to improve academic performance.

 

The current review provides an overall view of ATS use by MS in Latin America. It notes that ATS use is more prevalent among MS than the rest of the university population and the general population in South and Central America, when compared with data provided by the Report on Drug Use in the Americas (2019).(7,17,19,20,22-24)

 

In relation to the use of ATS among university students, according to the Report on Drug Use in the Americas 2019, Colombia reports a lifetime prevalence of 1.1% of amphetamine use(6), well below that reported by the Acevedo et al. study(20), of 42.3% use by Colombian MS.

 

Regarding the prevalence over the last year of the use of stimulants without medical prescription in the general population, Chile presents a last-year prevalence of 0.3% in 2016(6). In May 2019, the first study of drug use in Chilean higher education was published (without specifying the university courses in question). This study, carried out by the National Service for the Prevention and Rehabilitation of Drug and Alcohol Consumption (SENDA) during 2018, found that 0.8% of university students use amphetamines without a medical prescription(35), a lower figure compared to the study by Romero et al.17), which showed a prevalence of 2.1% in MS.

 

In relation to the main motivation for non-medical ATS use, improving academic performance is preeminent(20-22,24,27,27-29). This coincides with the reported results of an American review conducted in Maryland which gives the reasons for using methylphenidate as improving intellectual performance (23%) and increasing efficiency when performing academic tasks (22%)(10). Likewise, a statistically significant association was observed between ATS consumption and advance in academic years completed(20,22,29), as well as an association between the start of ATS use and the start of a university career(21,28). Both associations agree with reports by studies carried out in the USA(12) and a review carried out in Spain.(34)

 

Among the studies included in this review, Latin American MS appear to use them, especially in more demanding situations, and usage increases as academic studies progress(23,29). In studies conducted in Colombia by Baron et al.(29), amphetamines are taken once or twice a week by 16.5% of MS, making them the biggest consumers of all other students.(20)

 

Regarding the use of ATS among MS and students following other disciplines, it is observed that, of disciplines in the health area, Medicine reports the highest percentage of consumption(30). When compared with other non-medical careers, Medicine once again ranks top.(19,20)

 

It is important to note that there is significant heterogeneity regarding the type of sample studied in the studies reviewed. Furthermore, in some of the studies included, the analysis performed was solely descriptive, so it is not possible to know if the differences found are significant.

 

Of the articles selected, no studies were found on the quality of life and the consequences of the acute and prolonged use of ATS by MS. This makes it even more difficult to assess and understand the eventual risks that they are exposed to, and, therefore, to adequately direct preventive measures. prevention and treatment. A study by Melo et al.(36), which sought to identify factors that influence the quality of life of MS, found that the use of stimulants was “sometimes” and “always” negatively associated with the domains related to physical and psychological health in the World Health Organization’s Questionnaire on the Quality of Life (WHOQOL-BREF)

 

Finally, the studies reviewed have other important limitations:

- In general, samples were small, which limits large-scale interpretation of the results.

- In several studies, the type of ATS studied was not specified. It is not clear if the general term “amphetamine-type stimulants” refers to amphetamine and/or methamphetamine, medicines that contain amphetamine-type stimulants, or all of them together.

- In most of the studies reviewed, details are not given of the statistical analysis performed.

 

In summary, MS in Latin America have a higher consumption of ATS without medical prescription than students following other university disciplines and the general population. The apparent motivation is to achieve better academic performance. There is an evident need to carry out new studies, including in our country (where there is only one published study), Statistical precision and the evaluation of associated risk factors need to be improved, the size of survey samples increased, and long-term effects studied in detail. Progress in these areas will make it possible to take better clinical decisions on prevention and treatment.

 

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