Przegląd Lekarski 2017 / 74 / 8 353

Marek STOPA1

Mateusz ŁOBACZ1

Magdalena NIEMCZYK1

Karolina RUTKOWSKA1

Agata RADKO1

Agnieszka OLSZANECKA2

1Studenckie Koło Naukowe przy I Klinice Kardiologii i Elektrokardiologii Interwencyjnej oraz Nadciśnienia Tętniczego UJCM

2I Klinika Kardiologii i Elektrokardiologii Interwencyjnej oraz Nadciśnienia Tętniczego UJ CMKierownik:Prof. dr hab. n. med. Danuta Czarnecka

Additional key words:dietary supplementsover-the-counter drugsarterial hypertension

Dodatkowe słowa kluczowe: suplementy dietyleki dostępne bez receptynadciśnienie tętnicze

Address for correspondence:Dr med. Agnieszka Olszaneckaul. Kopernika 1731-501 Krakówtel/fax: + 48 12 424 73 00e-mail: agnieszka.olszanecka@uj.edu.pl

prAce oryginAlne

Prevalence of dietary supplements and over-the-counter drug use in patients with arterial hypertension

Częstość stosowania suplementów diety i leków dostępnych bez recepty wśród pacjentów z nadciśnieniem tętniczym

Conflict of interest: Authors not declared conflict of interest

Introduction: Dietary supplements (DS) and over-the-counter drugs (OTC) are frequently advertised as a natural treatment and management of many disorders. DS/OTC can in-terfere with biotherapeutic action of prescribed medication and this is of particular concern in patients with cardiovascular disease, many of whom are on long term treatment.

Aim: The aim of the study was to analyze the frequency of use of DS/OTC among patients with arterial hy-pertension as well as factors deter-mining its use and patients’ knowl-edge about possible interactions with conventional medication.

Materials and Methods: The study was conducted in the Outpatient Hy-pertensive Clinic in the Tertiary Car-diac Center. Self-prepared question-naire was administered among 151 hypertensive patients (58% females, age range 18-80 years). Regular DS/OTC use was defined as taking them at least 3 times per week.

Results: In the examined popula-tion of hypertensive patients regular use of DS/OTC was declared by 67% subjects (n=101). The most com-monly, regularly used substances were minerals and microelements (n=61, 60.4%), vitamins (n=49, 48.5%) and analgesics (n=19, 18.8%). Re-sponders also indicated regular use of drugs increasing the immunity (n=19, 18.8%), relieving the gastro-intestinal symptoms (n=19, 18.8%) and omega acids (n=19, 18.8%). There were no differences in the fre-quency of DS/OTC use in relation to number of antihypertensive drugs, educational level, age and income. Women are more frequent regular users of DS/OTC than men (n=65 vs n= 36, p=0.03). Only 38% of respond-ers always consulted the use of DS/OTC with a doctor. The majority of responders (52%) is not aware of possible influence of DS/OTC on an-tihypertensive medication or blood pressure control. Cost of DS/OTC in

Wstęp: Suplementy diety (DS) i leki sprzedawane bez recepty (OTC) są reklamowane jako naturalny spo-sób leczenia wielu schorzeń i dole-gliwości. DS/OTC mogą wchodzić w interakcje z lekami przepisywanymi przez lekarzy. Jest to istotna kwestia szczególnie u pacjentów z choroba-mi układu krążenia, którzy wymagają długoterminowej terapii.

Cel pracy: Analiza częstości sto-sowania DS/OTC wśród pacjentów z nadciśnieniem tętniczym oraz ana-liza czynników mogących mieć wpływ na tę częstość, a także analiza wiedzy pacjentów na temat możliwych inte-rakcji z lekami przepisywanymi przez lekarza.

Materiały i metody: Badanie zo-stało przeprowadzone w klinicznej poradni nadciśnieniowej w ośrodku referencyjnym. Samodzielnie skon-struowany kwestionariusz został wy-pełniony przez 151 pacjentów z nad-ciśnieniem (58% kobiet, zakres wieku 18-80 lat). Regularne spożycie DS/OTC zostało zdefiniowane jako użycie co najmniej jednego preparatu przy-najmniej 3 razy w tygodniu.

Wyniki: W badanej populacji pa-cjentów z nadciśnieniem tętniczym regularne stosowanie DS/OTC stwier-dzono u 67% ankietowanych (n=101). Najczęściej stosowanymi prepara-tami były: minerały i mikroelemen-ty (n=61; 60,4%), witaminy (n=49; 48,5%), i środki przeciwbólowe (n=19; 18,8%). Ankietowani zgłaszali również częste stosowanie preparatów zwięk-szających odporność (n=19; 18,8%), łagodzących dolegliwości z układu pokarmowego (n=19, 18,8%) i kwa-sów omega (n=19; 18,8%). Nie wy-kazano istotnych statystycznie róż-nic w częstości stosowania DS/OTC w zależności od liczby leków na nad-ciśnienie, wykształcenia, wieku i do-chodów. Wykazano częstsze regular-ne stosowanie DS/OTC w porównaniu do mężczyzn (n=65 vs n=36; p=0,03). Zaledwie 38% badanych zawsze kon-sultowało użycie DS/OTC z lekarzem.

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23% of responders is equal or higher than cost of pre-scribed drugs.

Conclusion: Two thirds of hypertensive patients are regularly using DS/OTC. Half of them are not aware of possible interactions with antihypertensive therapy and influence of blood pressure control. The perception that nonprescription therapies are unnecessary to report dur-ing medication history taking should be changed. DS/OTC are the important position in the responders budget.

Większość ankietowanych (52%) nie zdaje sobie sprawy z możliwego wpływu DS/OTC na skuteczność leczenia obniżającego ciśnienie tętnicze krwi. Wydatki na DS/OTC u 23% badanych są równe lub wyższe w porównaniu do wydatków na leki przepisane przez lekarza.

Wnioski: Dwie trzecie pacjentów z nadciśnieniem tęt-niczym regularnie stosuje DS/OTC. Połowa z nich nie jest świadoma możliwych interakcji z lekami przeciwnadci-śnieniowymi i negatywnego wpływu na kontrolę ciśnienia tętniczego. Przekonanie, że nie ma potrzeby zgłaszania stosowania produktów bez recepty podczas rozmowy lekarza z pacjentem powinno zostać zmienione. DS/OTC stanowią istotną pozycję w budżecie ankietowanych.

Introduction Dietary supplement is a product inten-

ded to supplement a normal diet. It pro-vides a concentrated source of vitamins, minerals or other substances and its pur-pose is to cause certain nutritional or physi-ological effect [1]. Over-the-counter drugs (OTC), are defined as drugs, that can be bought without a doctor’s prescription [2]. Both DS and OTC are considered to be safe to use without medical consultation by the general population and its use has be-come widespread. In 2012 polish citizens spent over 2.5 billion zlotys on DS and 5.5 billion zlotys on OTC.

These products are frequently adver-tised for the natural treatment and man-agement of many disorders. According to National Broadcasting Council number of commercials increased 20 times from 1997 to 2015. Due to quick and easy access and frequent adverts the use of these products is common in general population [3].

DS and OTC may pose a threat to health in several ways including over-consumption or possible risk of toxicity in patients with certain diseases. The other concern is interference of DS with biothera-peutic action of prescribed medication, as they often share similar enzymatic path-ways for their metabolism. These interac-tions may lead to severe adverse reactions [4].

Hypertension is one of the most com-mon (medical) conditions affecting more than 10 mln of polish adults [5]. It is one of the modifiable risk factors of cardiovascu-lar diseases, which are the cause of almost a half of all deaths in polish population. Therefore, the treatment of hypertension is not only the medical problem, but also a significant social and economical issue. However, NATPOL 2011 study showed good control of hypertension only in 23% of patients [5]. Long-term medication is necessary to stabilize blood pressure. Un-controlled use of DS and OTC may influ-ence the effectiveness of the treatment [6]. Moreover, it may lead to life-threatening events [7], according to previous studies which proved patients deficits of knowl-edge to avoid adverse effects [8].

The main purpose of the study was to evaluate the frequency of use of the DS and OTC among hypertensive patients. The aim was to assess patients’ awareness of possible interactions between DS and OTC with conventional medication. The other is-sue of interest was information the patients

seek before taking supplements or OTC for the first time - whether they consult it with the doctor or read patients informational leaflet. Furthermore we were searching for possible factors which may determine the use of DS and OTC. We wanted to evalu-ate the monthly cost patients spent on DS and OTC in comparison to their expenses on prescribed medication.

Material and MethodsThe study was conducted in the Out-

patient Hypertensive Clinic in the Tertiary Cardiac Center, First Department of Car-diology, Interventional Electrocardiology and Hypertension Jagiellonian University Medical College in Cracow from November 2015 to January 2016. Self-prepared ques-tionnaire was administered among adult hypertensive patients, who volunteered to take part in the study. Participants complet-ed the questionnaire themselves.

The anonymous questionnaire con-sisted of three parts: 1. demographics (6 questions), 2. DS and OTC part (8 ques-tions and a table with different types of DS and OTC listed), and 3. hypertension and other comorbidities (10 questions). The study was approved by local Ethical Re-view Board.

For each type of DS and OTC patients were asked about frequency of its use-answers varied from never to more than once per day. Based on reported frequency respondents were divided into two groups-regular and non regular users. Regular OTC or DS use was defined as taking them at least 3 times per week. Omitted were medications for cold, as the study was con-ducted between November and January, when the use of such agents is increased and general frequency of their intake would be unreliable. The data was analysed using descriptive statistics. Qualitative variables were assessed by chi-squared test. Analy-ses were performed with Statistica 12 soft-ware (StatSoft Inc.).

ResultsThe questionnaire was completed by

151 patients (58% women, age range 18-80 years).

Regular use of supplements and OTC was declared by two thirds of patients. De-tailed results are presented in Table I. Fur-ther analyzes will be based on the regular users group.

The frequency of consumption of vario-us products is presented in Figure 1. The

most popular were: minerals and microele-ments (60.4%), vitamins (48.5%), analge-sics (18.8%), omega acids (18.8%), sup-plements increasing the immunity (18.8%), and OTC relieving gastrointestinal symp-toms (18.8%).

There were no statistically significant differences in terms of regular use of DS and OTC between groups divided by: num-ber of antihypertensive drugs, education level, income and age (p>0.05), as presen-ted in Table II.

Statistically significant difference was found only in gender factor. Women were more frequent regular users than men (n=68 versus n=33, p=0.03).

As shown in Table III, patients seek information more often by reading the pa-tients’ informational leaflet than consulting with a doctor. 66% of respondents always read the leaflet, 21% do it sometimes. As for consultation with a doctor the results were 37% and 33% respectively.

Table IV depicts patients’ knowledge about possible negative effects of supple-ments and OTC and their possible interac-tions with other drugs. Almost half of the patients were not aware of that risk.

The last element of the study focused on patients expense on supplements and OTC in comparison to prescribed drugs. Al-most a quarter of patients spent the same or even more money on supplements and OTC in comparison to drugs prescribed by a doctor, as shown in the Table V.

DiscussionThis research proved that majority

(66%) of hypertensive patients use DS and OTC regularly. Common consumption of these products was shown also in other studies conducted both in Poland and other countries [9-13]. Qato et al proved that in American elderly population OTC were used by 37.9%, while DS were used by 63.7% [14]. The online German study found out a 7-day OTC drug use preva-lence to be 46.3 % among German adults [15]. Our study has shown higher prevalen-ce of DS and OTC consumption in compa-rison to these studies. It may be connected to various factors. Firstly in our study we analysed use of DS and OTC combined in contrast to other research. Nowadays in Poland due to much easier registration of DS than OTC some companies bring to market DS products with identical composi-tion to OTC drugs (for example Rutinoscor-bin and Rutinacea) [16]. Majority of respon-

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dents do not remember precise names of products they take, so it is very problematic to ask specifically about products only from one of this groups. Moreover we asked about the use of these substances over the previous year which is a significantly longer period of time in comparison to f.e. 7days in German research. The other issue may be different definitions of regular use. We defined it as the intake of DS or OTC at least 3 times a week whereas Qato et al. [14] defined its regular intake as at least one daily or weekly over period of time. We chose such criteria as prolonged and regu-lar consumption of chemical products may lead to cumulative effects and pose a gre-ater threat of interactions with conventional antihypertensive treatment [17]. Although different methods were used in the respec-tive studies, e.g. telephone and online su-rveys versus face-to-face interviews, and the studies included different populations and age groups, there seems to be an in-crease in supplements and OTC use over time. This effect can be linked with incre-asing accessibility to DS and OTC which may be purchased not only in pharmacies but also in almost every market. Growing consumption of these products may be also associated with a widespread belief that they support general health [18].

Vitamins and microelements were the most popular products among our respon-dents, which is a common trend confirmed by many studies, not only among polish po-pulation [19,20]. It is caused mostly due to frequent advertising [21]. In 2015, the vita-min supplements segment dominated the market in the US with more than 47% of a market share. About half of the American population takes multivitamins, and many of them take specific product recommen-ded on certain conditions [22].

Our results has shown that the use of DS and OTC is common in all sociodemo-graphic groups. However our study sho-wed that women are more frequent users of DS and OTC than men. This confirms general trend reported in many studies [15,19,23,24]. Women are generally more concerned about their health and willing to contact doctors. Therefore, DS and OTC consumption may be considered by them as another way of preventing illnesses. Age is not determining frequency of use of DS and OTC which was confirmed also by Centre for Public Opinion Research (CBOS) study [19]. Although CBOS rese-arch has proven that educational level is a significant aspect, our study did not re-veal any significant differences between patients with different levels of education.

Majority of respondents claim to read the leaflet at least sometimes before taking DS or OTC for a first time, but only one third always consult its use with a doctor. This proves patients’ confidence in safety of these products. Patients and doctors often omit discussion on DS and OTC while giving or taking a medication histo-ry. Other studies tried to explain the lack of communication between patients and do-ctors. Bakuri has proven that the number of DS intake reported by the patients can be

Table iFrequency of supplement / OTC consumption among hypertensive patients. Częstość spożycia suplementów diety/leków OTC przez pacjentów z nadciśnieniem tętniczym.

Regular/non regular users n (%) Frequency of use n (%)Regular 101 (67%) >1/day 9 (6%)

1/day 75 (50%)3-6/week 17 (11%)

Non regular 50 (33%) few times a month 24 (16%)few times a year 18 (12%)

never 8 (5%)

Table iiAnalysis of factors, which may determine the frequency of use of DS/OTC (analyzed with chi-squared test).Analiza czynników, mogących mieć potencjalny wpływ na częstość stosowania suplementów diety/leków OTC (analizowane przy pomocy testu chi-kwadrat).

Factor 1 Factor 2 Factor 3 Factor 4Number of

antihypertensive drugsregular

users (%)Educational

levelregular

users (%)Income

[zł]regular

users (%) Age regular users (%)

1 61 Basic 70 <1000 75 18-40 622 68 Vocational 78 1000-2000 66 41-60 613 72 Secondary 60 2000-3000 54 61-70 77

≥4 63 Higher 67 >3000 84 >70 63p=0.99 p=0.83 p=0.79 p=0.94

Table iVData on patients’ knowledge of DS/OTC adverse effects.Dane na temat stanu wiedzy pacjentów o działaniach niepożądanych suplementów diety/leków OTC.

Knowlegde of potential adverse effects n (%)

Yes 49 (48%)Do not know 26 (26%)

No 26 (26%)

Figure 1Frequency of use of specific products among regular users. Częstość stosowania poszczególnych produktów wśród stosujących DS/OTC regularnie.

Table VExpenses on DS/OTC in comparison to expenses on drugs prescribed by doctor.Wydatki przeznaczane na suplementy diety/leki OTC w stosunku do wydatków na leki przepisywane przez lekarzy.

What makes up a larger part of respondents’ budget? n (%)

Prescribed drugs 78 (77%)Equal 12 (12%)

Supplements and OTC 11 (11%)

Table iiiSearching information about DS/OTC by hypertensive patients.Poszukiwanie informacji o suplementach diety/lekach OTC przez pacjentów z nadciśnieniem tętniczym.

Consultation with a doctor n (%) Leaflet reading n (%)

always 38 (38%) 66 (66%)sometimes 31 (30%) 21 (21%)

never 32 (32%) 14 (13%)

1

Figure 1 Frequency of use of specific products among regular users. Częstość stosowania poszczególnych produktów wśród stosujących DS/OTC regularnie.

6,9% 5,9%

7,9% 8,9%

11,9% 11,9% 12,9% 13,9%

18,8% 18,8% 18,8% 18,8%

48,5% 60,4%

OthersProstate supplements

Sedatives and sleeping pillsModulating cognitive function

Skin and nail supplementsSupplements for urinary tract infections

Improving blood circulationArthritis pain relief drugs

Relieving the gastrointestinal symptomsIncreasing the immunity

Omega acidsAnalgesics

VitaminsMinerals and microelements

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doubled by asking specifically about them versus not asking at all. Patients tend not to inform about the DS consumption use unless they are directly asked about it [25]. Consequently, medication histories should include documentation of any OTC medici-nes taken [26]. Above cited results are an important reason for encouraging doctors to initiate conversation with their patients about the use of DS and OTC.

Interestingly Blendon et al. indicated that some patients intentionally do not di-scuss the use of DS with their physicians. They believe that the doctors know little or nothing about these products and may be biased against them. Their belief in the po-tential health benefits was so strong, that they claimed to continue to take them even if the scientific, clinical research show that they were ineffective [27].

Over half of the respondents is not aware of possible interactions and adver-se effects of DS and OTC. Patients’ poor knowledge is demonstrated in other stu-dies and its level is even larger than in our research. Bakuri [25] shows that 69% of subjects were not aware of the side ef-fects and interactions of supplements with medications. Patients’ lack of knowledge is even more worrying due to fact that DS package in Poland do not contain patients’ information leaflet. Patients cannot verify safety of taking DS along with prescribed medication, which may lead to life thre-atening events. A 2013 report from the Government Accountability Office (GAO) found that over four years, the Food and Drug Administration received 6.307 reports of health problems from DS, including 92 deaths, hundreds of life-threatening condi-tions, and more than 1.000 serious injuries or illnesses. The GAO suggests that due to underreporting, the real number of inci-dents may be far greater [28]. The other re-search proved that 86% of the older adults with hypertension reported at least one self-medication practice that could result in an adverse drug interaction [29]. Research examining prescription drug use suggests that older adults are two to seven times more likely to experience an adverse drug reaction and people over 65 years of age account for 61.5% of emergency depart-ment visits associated with them [30]. That is a significant context in relation to our stu-dy as more than a half of our respondents were aged over 60 years and the prevalen-ce of hypertension increases with age.

To our knowledge this is the first study which compares amount of money spent on conventional medication to costs of DS and OTC. Our research shows that one per four patients that require long-term medical therapy spends comparable amount of mo-ney on self-medication and drugs prescri-bed by doctors. That is an issue of concern, as many studies show, that the DS have no real beneficial effects and they can even be harmful [4,9,26]. More emphasis should be

put on the standard treatment of common diseases like hypertension, as the com-pliance to therapy is still poor-in Poland treatment of 36% hypertensive patients is ineffective [5].

ConclusionThis study suggests that DS use is a si-

gnificant issue which may concern even two thirds of the hypertensive patients. The fact that one third of respondents take sup-plements on their own initiative and most of them do not know about possible inte-ractions with conventional medication and influence on blood pressure is alarming. Given the results of this research doctors should pay more attention to supplement use during the history taking. DS and OTC drugs have an important position in the budget of polish hypertensive patients.

References1. Ustawa z dnia 25 sierpnia 2006 r. o bezpieczeń-

stwie żywności i żywienia. Dziennik Ustaw nr 171, poz 1225. 2006; 258: 1-70.

2. Rozporządzenie Ministra Zdrowia z dnia 14 listo-pada 2008 r. w sprawie kryteriów zaliczenia pro-duktów leczniczego do poszczególnych kategorii dostępności. 2008; 217: 12074-12075.

3. Krążyńska K: Apteczny rynek farmaceutyczny i konsumpcja leków w Polsce. Konsumpcja i roz-wój. 2013; 2: 108-119.

4. Trivedi R, Salvo MC: Utilization and Safety of Common Over-the-Counter Dietary / Nutritional Supplements, Herbal Agents, and Homeopathic Compounds for Disease Prevention. Med Clin North Am. 2016; 100: 7125.

5. Zdrojewski T, Rutkowski M, Bandosz P, Ga-ciong Z, Jędrzejczyk T. et al: Prevalence and control of cardiovascular risk factors in Poland. Assumptions and objectives of the NATPOL 2011 Survey. Kardiol Pol. 2013; 71: 381-392.

6. Czarnecka D, Jankowski P, Kopeć G, Pająk A, Zdrojewski T. et al: Polish Forum for Prevention Guidelines on Hypertension : update 2017. Kardiol Pol. 2017; 75: 282-285.

7. Fendrick AM, Pan DE, Johnson GE; OTC anal-gesics and drug interactions: clinical implications. Osteopath Med Prim Care. 2008; 2: 2.

8. Neafsey PJ, Shellman J: Misconceptions of older adults with hypertension concerning OTC medica-tions and alcohol. Home Healthc Nurse. 2002; 20: 300-306.

9. Waśkiewicz A, Sygnowska E, Broda G, Chwoj-nowska Z: The use of vitamin supplements among adults in Warsaw: is there any nutritional benefit? Rocz Panstw Zakl Hig. 2014; 65: 119-126.

10. Bieżanowska-Kopeć R, Leszczyńska T, Ko-peć A: Suplementacja diety studentów wyższych uczelni województwa małopolskiego witaminami i/lub składnikami mineralnymi. ZYWN-NAUK TECH-NOL JA. 2010; 4: 132-140.

11. Lieberman HR, Marriott BP, Williams C, Judel-son DA, Glickman EL et al: Patterns of dietary supplement use among college students. Clin Nutr. 2015; 34: 976-985.

12. Wróblewska J, Klocek M, Czarnecka D: Ocena spożycia wielonienasyconych kwasów tłuszczo-wych wśród młodych kobiet i mężczyzn chorują-cych na nadciśnienie tętnicze. Przegl Lek. 2016; 73: 382-387.

13. Skrzek A, Stolarz-Skrzypek K, Klocek M, Czar-necka D: Suplementacja preparatów magnezu u mężczyzn i kobiet z nadciśnieniem tętniczym. Przegl Lek. 2016; 73: 368-372.

14. Qato D, Wilder J, Schumm L, Gillet V, Alexander g: Changes in Prescription and Over-the-Counter Medication and Dietary Supplement Use Among Older Adults in the United States, 2005 vs 2011. JAMA Intern Med. 2016; 60612: 473-482.

15. Barrenberg E, Garbe E: Use of over-the-counter (OTC) drugs and perceptions of OTC drug safety among German adults. Eur. J. Clin. Pharmacol. 2015; 71: 1389-1396.

16. Dąbrowski T: Producenci suplementów zacierają ręce nad kulawym prawem. http://www.rynekaptek.pl/prawo/producenci-suplementow-zacieraja-rece-nad-kulawym-prawem,3382.html.

17. Hayes DP: Nutritional hormesis. Eur J Clin Nutr. 2006; 61: 147-159.

18. Conner M, Kirk SFL, Cade JE, Barrett JH: Why do women use dietary supplements? The use of the theory of planned behaviour to explore beliefs about their use. Soc Sci Med. 2001; 52: 621-633.

19. Rogulska B, Feliksiak M: Stosowanie leków do-stępnych bez recepty-komunikat z badań CBOS. 2010.

20. Piekarzewska M, Zajenkowska-Kozłowska A: Zdrowie i zachowanie zdrowotne mieszkańców Polski w świetle Europejskiego Ankietowego Ba-dania Zdrowia (EHIS) 2014 r. Główny Urząd Sta-tystyczny. 2015.

21. Ulatowska-Szostak E: Wpływ reklamy na zakup leków, parafarmaceutyków i preparatów witami-nowych w opiniach klientów aptek-porównanie lat 2002 i 2007. Probl Hig Epidemiol. 2008; 89: 441-444.

22. Smith S: Supplement Market in the US 2016-2020. Market outlook of the supplements mar-ket in the US. 2015. http://www.prnewswire.com/news-releases/supplement-market-in-the--us-2016-2020-300190028.html.

23. Nielsen MW, Hansen EH, Rasmussen NK: Pre-scription and non-prescription medicine use in Denmark: Association with socio-economic posi-tion. Eur. J. Clin. Pharmacol. 2003; 59: 677-684.

24. Schlegel-Zawadzka M, Barteczko M: Ocena stosowania suplementów diety pochodzenia na-turalnego w celach prozdrowotnych przez osoby dorosłe. ZYWN-NAUK TECHNOL JA. 2009; 4: 375-387.

25. Bakuri S: The Reporting of Supplement Use by Dental Patients on Their Medical History Question-naire. 2014.

26. Barnett NL, Denham MJ, Francis SA: Over-the--counter medicines and the elderly. J R Coll Physi-cians Lond. 2000; 34: 445-446.

27. Blendon RJ, DesRoches CM, Benson JM, Bro-die M, Altman DE: Americans’ views on the use and regulation of dietary supplements. Arch Intern Med. 2001; 161: 805-810.

28. Interlandi J: Supplements Can Make You Sick. http://www.consumerreports.org/vitamins-supple-ments/supplements-can-make-you-sick/.

29. Neafsey PJ, Shellman J: Adverse self-medica-tion practices of older adults with hypertension attending blood pressure clinics: Adverse self-me-dication practices. The Internet Journal of Mental Health. 2002; 5: 1-9.

30. Albert SM, Bix L, Bridgeman MM, Carstensen LL, Dyer-Chamberlain M. et al: Promoting safe and effective use of OTC medications: CHPA-GSA national summit. Gerontologist. 2014; 54: 909-918.

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