According to the Law of medicines and medical devices of the Republic of Serbia, medicine is defined as a product aimed at preventing or treating illness and improving physiological functions. Drugs can be given without a prescription. Medicine and additional medical devices which could be bought without a prescription are called “Over the Counter Drugs” (OTC). These preparations are usually safe to use due to its therapeutic range and minimum toxicity, and they have been used in Serbia for about ten years now. OTC preparations include: vitamins and minerals, antihistamines to be applied locally, non-narcotic analgesics and antipyretics, drugs for treating eye and ear diseases, drugs for a local and oral treatment of nasal mucosa, secretolytics and mucolytics, laxatives, antifungals and anti-rheumatic drugs to be used locally, and the OTC list of drugs is determined by the Ministry of Health of the Republic of Serbia [1].

The leader in introducing OTC preparations on the market was the United States of America. Namely, OTC drugs were introduced to USA about twenty years ago and today there are over 300.000 registered OTC drugs [2].

Numerous researches show an increase in the number of people all around the world who are practicing self-treatment, which consequently leads to an increased need for OTC drugs [3-5].

Self-treatment and the use of OTC drugs without consulting a doctor have some advantages, but they also carry some disadvantages. The main advantage is the fact that it enables an individual to actively and independently decide about their own treatment, it saves time and reduces the number of visits to a doctor and generally reduces the work load on doctors, it reduces the time spent in waiting rooms for a check-up and health care expenses [6]. However, individual expenses are rising, there are more side effects, there may be some dosage errors, as well as masking some serious disease symptoms which could stay unrecognized for a longer period of time [7, 8].

Socio-demographic characteristics of OTC users as well as the analysis of the relation between OTC drug use for self-medication and vitamins for boosting the immune system could be interesting for both the creators of the health care policies and for many pharmaceutical companies which run businesses on the territory of the Republic of Serbia.

The goal of the research is to look into socio-demographic factors of the interviewees who use OTC drugs for self-medication and OTC vitamins and minerals for boosting the immune system.

For the purpose of the study, data obtained through the National research on health condition of the population in the Republic of Serbia in 2013 were used [9]. The total number of interviewees was 14082, aged 18 and more.

The sample included 14082 interviewees. Out of the given number, 3966 (27.1%) interviewees used drugs/curatives from the group of OTC preparations in the last two weeks. The analysis of the interviewees who used OTC preparations show that in the last 2 weeks 56% (2170) of the interviewees used vitamins and other preparations for boosting the immune system while 44% (1703) of the interviewees used OTC for self-medication. Average age of the interviewees who used OTC preparations was 50.83 ± 16.84 and those who used OTC vitamins were 2 years older on average than interviewees who used OTC for self-medication which represents a statistically significant difference (p < 0.05).

Women and highly educated people use OTC drugs more often. The poorest people buy OTC drugs least frequently and when they do, they buy drugs for self-medication rather than vitamins. Every fifth citizen of Belgrade buys vitamins, and drugs for self-medication are most often used by citizens of Sumadija and West Serbia as well as South and East Serbia. Unemployed people and those coming from rural areas, as well as those who have never visited a specialist use OTC drugs very rarely. Every third interviewee who has a chronic disorder uses OTC drugs. Out of the interviewees who were on a sick leave in the last year, vast majority used OTC drugs from the group of vitamins for boosting the immune system. The interviewees who consider their health as very good very often don’t use OTC drugs (Table 1).

The results of the binary logistic regression for the use of OTC drugs for self-medication and for boosting the immune system show that statistically significant predictors for the use of both kinds of OTC drugs were the same: education level, well-being index and region. The strongest predictor for the OTC drug use was education. Therefore, people who have primary or secondary education use OTC drugs for self-medication 0.3 and 0.6 less often than highly educated interviewees, respectively. In contrast to that, interviewees who have finished primary or secondary school most often buy OTC vitamins and drugs for boosting the immune system. Namely, people who have elementary education or high school education use OTC vitamins and herbal preparations for boosting the immune system 4 times and twice as often than highly educated people, respectively. When we consider financial situations of our interviewees, it can be concluded that the poorest people and middle class use OTC drugs for self-medication twice or 0.7 times less often than the rich, respectively. As far as OTC vitamins and herbal immunoregulators are concerned, the situation is completely opposite. The poor interviewees use OTC vitamins 1.4 and 1.9 times more often that the rich. Citizens of Sumadija and West Serbia use OTC drugs for self-medication 0.6 times less often that the citizens of South and East Serbia, but they use OTC vitamins and preparations for boosting the immune system significantly more often (twice as often) than citizens of South and East Serbia (Table 2).

The analysis of the OTC drug use on a national level enables us to understand not only the scope of use but also the type of OTC drugs used, as well as to define predictors for specific population groups in relation to their socio-demographic characteristics and health condition. The possibility of self-medication reduces the number of visits to a doctor and general work load of doctors [12, 13]. More detailed analysis of the interviewees who buy OTC drugs for self-medication, which one can get in the pharmacy for free with a prescription, provides medical policy makers with information related to the work quality and organization of the health care system, as well as possible reasons for not providing necessary health care services.

It frequently happens that people use drugs prescribed by doctor alongside with OTC drugs. In Serbia, the prevalence of polypharmacy and OTC drug use in the elderly aren’t different from other industrialized countries although there is a risk of interaction of OTC drugs with other drugs, and patients are obliged to inform a doctor about the OTC drug they use [14, 15]. Paradoxically, the least safe OTC drugs for self-medication are most often used, especially antibiotics and nonsteroidal anti-inflammatory drugs, both in Serbia and in some countries of Europe and the world [16-19]. Self-medication among students of School of Medicine, University of Belgrade showed that 79.9% students used it. The most frequently self-prescribed medications were analgesics [20]. Similarly, resarch self-medication practice and used drugs for self-medicaton among medical and pharmacy students in Croation in period 1977-2001 showed that was a routine practice and difference between the 2001 and 1977 surveys was not found. The students were most often used NSAIDs and antibiotics that they had in their homes [21].

The role of the pharmacist during the process of buying OTC drugs is enormous. However, numerous researches conducted in Australia, Japan, Argentina and Canada question their professionalism and their role in the entire system [22-25].

The analysis of the OTC drug users according to gender shows that in most of the studies, women use OTC drugs significantly more often; however, there are results that show the contrary [26, 27]. The analysis of the type of OTC drugs shows that older people and people suffering from chronic diseases use OTC drugs for self-medication more often than OTC vitamins and minerals for boosting the immune system, which is completely opposite to our results [28].The factor of education in the OTC drug use is very significant both in our study and in many other studies [29-31]. More educated interviewees use OTC drugs for self-medication more often [27]. The results of the research show that poor interviewees buy OTC drugs for self-medication less often and that could be explained with the fact that certain drugs can be obtained for free with a prescription, which was confirmed in numerous previous studies [32, 33].

For the past few years, an increase in the number of OTC products on the market and the need for them could be noticed in Serbia. Highly educated and rich people most often, voluntarily and with the advice of pharmacist buy OTC drugs for self-medication, while poor and less educated people more often buy OTC drugs for boosting the immune system which doctors do not issue prescriptions for. These findings are of paramount importance to both the health care policy creators and to OTC drug vendors which are doing business on the territory of the Republic of Serbia.