Herbal Medicine Use Among Transplant Recipients in Saudi Arabia: Prevalence and Risk Awareness

Introduction

The use of herbal medicine, defined as the utilization of medicinal plants and plant-based products to prevent and treat illnesses, has a long history and continues to gain popularity worldwide. This practice is deeply rooted in cultural traditions and everyday healthcare, particularly in regions like Saudi Arabia [1]. Herbal medicine is commonly perceived as a natural and safe alternative or complement to conventional medical treatments, as evidenced by a national survey in Saudi Arabia that found 88.4% of participants reported using herbal remedies as part of their healthcare routines [2].

The use of herbal medicines in populations with unique medical needs, such as solid-organ transplant recipients, presents significant challenges. These patients depend on precisely managed immunosuppressive therapies to prevent organ rejection, and the incorporation of herbal remedies into their treatment regimens can lead to complex drug interactions. Herbal medicines are known to interfere with immunosuppressive agents, potentially diminishing their effectiveness or exacerbating adverse effects, thereby increasing the likelihood of graft rejection, drug toxicity, and other severe complications [3–5]. A primary mechanism driving these interactions is the inhibition or induction of cytochrome P450 enzymes, which profoundly impacts the metabolism of immunosuppressive drugs and complicates their pharmacokinetics and clinical management [6]. For instance, St. John’s Wort, a commonly used herbal remedy for mild depressive symptoms, induces cytochrome P450 enzymes, reducing the effectiveness of calcineurin inhibitors and consequently elevating the risk of graft rejection [7,8].

Despite these risks, the use of herbal medicine among transplant recipients is not uncommon, as exemplified by a study conducted in Poland that found 58% of transplant recipients reported using herbal remedies as part of their treatment [9]. This highlights a global pattern where patients, even those with complex medical needs, turn to alternative therapies, often without fully understanding the associated risks. Furthermore, healthcare professionals may not always be aware of their patients’ use of herbal medicine, which could complicate the management of post-transplant care.

In Saudi Arabia, while the prevalence of herbal medicine use in the general population is well-documented, little is known about its use specifically among transplant recipients [2,10,11]. The unique cultural context in the Kingdom, where herbal medicine is interwoven with traditional beliefs, makes it crucial to understand how this population navigates their post-transplant healthcare choices. There is a growing need to examine whether transplant recipients are aware of the potential interactions between herbal remedies and their prescribed medications and whether they are receiving appropriate counseling from healthcare professionals.

Therefore, this study aimed to investigate prevalence, knowledge, and attitudes regarding the use of herbal medicine among solid-organ transplant recipients in Saudi Arabia. These findings will offer important insights to clinicians, enhancing transplant outcomes.

Material and Methods

STUDY DESIGN:

This was a cross-sectional multicenter study aimed to assess the prevalence, knowledge, and attitudes regarding herbal medicine use among solid-organ transplant patients.

POPULATION:

The target population included solid-organ transplant recipients residing in Saudi Arabia. Convenience sampling was used to recruit participants from various transplant clinics. To ensure comprehensive coverage, data collection was conducted in 3 major regions of Saudi Arabia – Eastern, Western, and Central – with a transplant center in each region. All adult Saudi transplant recipients who provided informed consent were included. Exclusion criteria encompassed illiterate individuals and non-Saudis to ensure consistency in data collection and comprehension. Ethics approval was obtained from the Institutional Review Board (IRB) of Imam Abdulrahman Bin Faisal University (IRB-2023-05-502), and participants provided informed consent to ensure compliance with research ethics standards.

DATA COLLECTION:

Data were collected using a structured questionnaire that was adapted from a previously validated survey [2,12]. To ensure its relevance to the target population, the questionnaire was reviewed by a panel of experts in organ transplantation, who assessed it for face and content validity. Based on their feedback, necessary modifications were made, and culturally relevant questions were added to reflect local healthcare beliefs and practices related to herbal medicine use. The final questionnaire was divided into 4 sections.

A pilot study was conducted with a sample of 10 transplant recipients to assess the clarity and comprehensiveness of the questionnaire. Based on the pilot study results, minor modifications were made to enhance the wording and ensure the questions were easy to understand. For example, some of the phrasing in the knowledge and attitude questions was adjusted to improve clarity and avoid ambiguity. After these modifications, the questionnaire was finalized for full-scale data collection.

The first section of the questionnaire focused on sociodemographic information, including participants’ age, gender, type of transplant, and the duration since transplantation. Age was categorized into 5 groups: 18–30, 31–40, 41–50, 51–60, and 61+ years, while transplant duration was classified into 3 categories: <1 year, 1–2 years, and >2 years. Participants were also asked whether they had used herbal supplements before or after their transplant. If they answered affirmatively, follow-up questions explored the sources of information they consulted (eg, physician, pharmacist, leaflets, or the internet), the reasons for using herbal supplements (eg, effectiveness, price, or taste), and the frequency of use (daily or occasionally).

The second section assessed the prevalence of herbal medicine use, where participants were asked specific questions about their frequency of use both before and after their transplant. For those who reported using herbal supplements, further details were collected on the types of supplements used and their motivations for doing so. This helped provide insight into the reasons behind herbal supplement use and the perceived benefits among transplant recipients.

The third section evaluated participants’ knowledge of herbal medicine through a series of 3 questions that assessed their self-reported understanding of herbal supplements, their importance, and the potential risks of interactions with prescribed medications. The knowledge questions included: “I consider myself knowledgeable about herbal supplements,” “As a transplant recipient, I think it is important to be knowledgeable about herbal supplements,” and “Herbal supplements can affect medical treatment because of side effects or drug interactions.” Participants could respond with “Yes”, “No,” or “Maybe”. Responses were then used to categorize participants according to their level of knowledge, with those answering “Yes” to all 3 questions considered to have a higher level of knowledge.

The fourth section addressed attitudes towards herbal medicine. Participants were asked to rate their agreement with 5 statements related to the safety and efficacy of herbal supplements, as well as their beliefs regarding consulting healthcare professionals about herbal use. The statements included: “I believe herbal supplements are safer than manufactured medicine”, “I believe there is a benefit from using herbal supplements to prevent disease”, “I believe there is a benefit in using herbal supplements to cure diseases”, “I believe there is a benefit in using herbal supplements to treat symptoms of some diseases”, and “I believe that patients should be able to consult medical staff about using herbal supplements.” Responses were measured on a 5-point Likert scale, ranging from “Strongly disagree” to “Strongly agree”, with higher scores indicating more favorable attitudes towards herbal medicine.

The questionnaire was originally developed in English and subsequently translated into Arabic for participants whose native language was Arabic. Both the English and Arabic versions were validated to ensure linguistic and contextual accuracy. The data collection period spanned from 12/2023 to 9/2024.

STATISTICAL ANALYSIS:

Data collection and recording were completed using Google Forms, and all data were analyzed utilizing the Statistical Analysis System (SAS, North Carolina, USA, On Demand). Categorical variables were summarized using frequency and percentage distributions. To assess statistical differences between herbal supplement users and non-users, the chi-square test was applied, with a significance threshold set at P<0.05.

Results

The study population consisted of 203 organ transplant patients, with 68% being male and 61% having received their transplant more than a year ago. The prevalence of post-transplant herbal supplement use among the participants was 19.2%. While the use of herbal supplements increased with age, there was no statistically significant difference in usage based on age. Most participants were kidney transplant recipients (68%), followed by liver transplant recipients (28.6%). Additionally, 62.0% of herbal supplement users prior to transplantation stopped using them after transplant (P<0.0001). Furthermore, 81% of participants reported not receiving education on herbal supplements prior to transplantation, and 70% indicated the same after transplant (Table 1).

The study identified more than 18 types of herbal supplements used by the participants, either alone or in combination. The most commonly used were fenugreek, myrrh, and parsley. Importantly, over half of the herbal supplements were found to pose a potential cytochrome P450 enzyme-related risk of drug interactions with immunosuppressants such as tacrolimus (Figures 1, 2). Additionally, most participants relied on information from friends, family, or neighbors as their primary source of advice regarding herbal supplement use (Table 2).

The participants displayed varying levels of knowledge about herbal supplements. While 29.6% considered themselves knowledgeable, 70.4% reported a lack of knowledge. However, 74.9% of participants believed it is important for transplant recipients to be knowledgeable about herbal supplements. The study revealed a statistically significant difference in participants’ knowledge of herbal supplement risks (P=0.0007) between post-transplant herbal supplement users and non-users. Of the respondents, 61.6% reported being aware of the potential risks associated with herbal supplements. Notably, 88.0% of those who were knowledgeable about these risks did not use herbal supplements with potential immunosuppressant interactions. In contrast, among participants who lacked knowledge of herbal risks, 45.0% used supplements with potential interactions.

The participants’ attitudes towards the safety and benefits of herbal supplements were varied. While 65% disagreed or strongly disagreed that herbal supplements are safer than manufactured medications, 15% agreed or strongly agreed. Regarding the perceived benefits of herbal supplements in preventing disease, 29% of respondents agreed or strongly agreed, while 41% disagreed or strongly disagreed. Notably, 81% of patients agreed or strongly agreed that they should be able to consult medical staff about their use of herbal supplements, with only 13% disagreeing or strongly disagreeing, and 6% remaining neutral (Figure 3).

Discussion

This study provides an important look at the use of herbal supplements among post-transplant patients in Saudi Arabia, offering insight into the potential risks and underlying factors that influence this practice. As the first investigation of its kind in the region, the findings contribute valuable data to the ongoing discourse on herbal medicine use in vulnerable populations, such as transplant recipients.

Our study revealed that 19% of participants reported using herbal supplements after transplantation. Of those, 44.3% had used herbal supplements before transplantation, but only 38.0% continued their use after transplant. This decrease in usage is likely attributed to increased awareness of potential drug–herb interactions, concerns about complications, and guidance from healthcare providers. However, most herbal supplement users in our study obtained information from non-medical sources such as friends, family, or the internet. These findings are consistent with previous research on post-transplant populations. For example, Neff et al documented a 19% prevalence of herbal supplement use among liver transplant recipients, which aligns with our findings [13]. In kidney transplant recipients, the prevalence of complementary medicine use was 11.8%, with homeopathy (42.9%) and Chinese medicine (23.8%) being the most common [14]. In contrast, Foroncewicz et al reported a 58% prevalence of dietary supplement or herbal use among renal and liver transplant patients, which is a higher rate, likely due to their inclusion of vitamin supplements in their analysis [9].

The use of herbal products is common across various ethnic groups, and Saudi Arabia is no exception, where cultural and traditional practices strongly support the widespread use of herbal medicines [2,15]. However, in our study, cultural factors did not seem to influence herbal supplement use among Saudi transplant patients, as usage rates were comparable to those of other cultural backgrounds. Notably, there was also no significant difference in usage between male and female participants, which contrasts with other studies in the Saudi population, where 85% of herbal remedy users were female [2].

Herbal medicines are often perceived as natural and inherently safe, leading many individuals to believe they are non-toxic and free from harmful effects. In our study, 15.25% of participants reported utilizing parsley as an herbal remedy, despite its conventional classification as a dietary or culinary ingredient. However, research shows that parsley juice, when administered to animals, can significantly reduce liver cytochrome P450 activity through the presence of natural compounds such as methoxsalen, potentially interacting with immunosuppressants [16]. Our findings suggest that 54.24% of the herbal supplements used by participants have the potential to interact with immunosuppressive medications. Although our study design did not allow us to assess the clinical significance of these interactions, existing research suggests that herbal supplements, especially those affecting calcineurin inhibitors, can impact immunosuppressive therapies and, in severe cases, may even lead to organ rejection [17–19].

In our study, knowledge about herbal supplements was found to be consistent across different participant groups. However, transplant recipients who were aware of the risks and potential drug interactions were significantly less likely to use herbal supplements (88.0% vs 15%, P=0.0007). This highlights the importance of patient education in both pre- and post-transplant care programs, which is reported to be crucial for achieving successful transplant outcomes [20,21]. Moreover, we observed a trend toward increased herbal supplement use in older patients and those more than 1 year after transplant. A systematic review conducted by José Edson de Souza Silva et al found that the result of limited awareness regarding the risks associated with herbal supplements is a higher prevalence of their use among older adults [22]. This finding is supported by our data, which show that 45.0% of participants who were unaware of the risks associated with herbal supplements used them, potentially risking interactions with their prescribed medications. This highlights the need for enhanced education focused on this patient group, emphasizing the importance of understanding the potential risks of drug–herb interactions.

Alarmingly, 81.1% of transplant recipients did not receive any education on herbal supplements prior to their surgery, and 70.4% reported not receiving any information after transplant. Nevertheless, 81% of patients strongly agreed or agreed that they should be able to consult medical staff regarding herbal supplement use, emphasizing the significance of the patient–provider relationship in ensuring effective medical care [23].

Conclusions

This study shows the continued and significant use of herbal supplements among transplant recipients in Saudi Arabia, with many patients still unaware or uninformed about the associated risks. The belief that natural products are inherently safe, combined with limited patient education and insufficient communication between healthcare providers and patients, poses serious health risks for vulnerable transplant populations.

To address this issue, it is essential to prioritize robust educational strategies and implement stricter regulatory measures to ensure transplant recipients are adequately informed about the dangers of herbal supplements. Expanding research in this area is crucial to better understand the motivations, prevalence, and outcomes of herbal supplement use in post-transplant care. Ultimately, a proactive approach involving comprehensive patient education, both before and after transplantation, is necessary to mitigate these risks and safeguard the health of transplant patients.