Evaluating the Knowledge and Attitude Among Dental Post-graduates Regarding Irrational Fixed Drug Combination: A Cross-sectional Study

INTRODUCTION

The WHO defines the rationality of a drug as “the use of the right drug in the right manner on the right patient at the right time at the lowest cost to them and their community”. The fixed drug combinations (FDCs) are defined as a combination of two or more active ingredients within a single form for pharmaceutical administration.^[1] In the present-day scenario, the global burden of diseases is constantly increasing; the top priority today for the drug manufacturers and health care professionals is to ensure the quality with a determined therapeutic benefit and reduced adverse effects.^[2] Food and Drug Administration (FDA), USA defines a combination product as “a product composed of any combination of a drug and a device or a biological product”. FDCs are rational: (i) when they act by diverse mechanisms, (ii) their pharmacokinetics and pharmacodynamics do not differ by a wide gap, and (iii) they do not add to toxicity. There are numerous medications available in the market, many of which are available as FDCs.^[3] FDCs have advantages over individual drug prescriptions in some situations. However, these must be weighed against issues like rising expenses and, in some circumstances, their irrationality. The practice of prescribing irrational combinations not only puts patients at unnecessary financial risk but also increases the risk of undesirable side effects and drug-drug interactions.^[4] In the Indian pharmaceutical market, FDCs are highly popular and have been flourishing in recent years.^[5] Irrational FDCs offer the greatest threat to patients since they put them at an undue risk of having adverse reactions. By creating awareness among dental post-graduates and clinicians about the efficacy, safety, appropriateness, and rationality of FDC, we might lessen the severity of these delinquencies.^[6] For any educational intervention to be effective and for the changes to be sustained and long-lasting, it should change the knowledge and understanding of the target population. Since dental post-graduates are primarily involved in patient care and management, they must be aware of the rationality and irrationality of the drugs they commonly prescribe in their practice. Chapters regarding prescribing the rational FDCs are again not part of the curriculum specified by the Dental Council of India (DCI) for dental graduates. Studies exploring the knowledge and understanding among dental post-graduates towards prescribing rational FDCs are limited. This present study is a multi-centric knowledge and attitude survey conducted among dental post-graduates in an academic set-up. This contemporary survey was intended to assess the knowledge and understanding among the dental post-graduates in various dental colleges in Chennai. This cross-sectional study was conducted online (through Google form) to explore the awareness of dental post-graduates (including all 9 departments) of various dental colleges in Chennai. The study aimed to evaluate knowledge and understanding among dental post-graduates about FDCs. Its merits, demerits, rationality, irrationality, and interventions to overcome the use of irrational FDC.

MATERIAL AND METHODS

This cross-sectional study was conducted online (through Google form) to explore the awareness of dental post-graduates (including all 9 departments) of various dental colleges in Chennai, Tamil Nadu, India, towards FDCs using a cross-adapted questionnaire from January 2025 to July 2025. The content authentication of the prepared questionnaire was pre-evaluated by 2 oral medicine experts, 1 oral surgeon, and 1 public health dentistry expert prior to ethical committee approval. The study protocol was reviewed and approved by the Institutional Ethics Committee (Approval No. 20250126). After approval, a prompt message application (WhatsApp) was used to distribute the survey.

A set of 18 MCQs was formulated based on the literature review.. Grounded on the queries raised and suggestions established by the Institutional Ethics Committee, a few questions were reviewed, and possible corrections were made and redistributed. The revised set of questions was based on the knowledge and attitude of the dental post-graduates regarding this subject and interested participants from all departments in various dental colleges in Chennai, Tamil Nadu. Participants not willing to participate in the study were excluded from the study. Descriptive statistics were made.

RESULTS

Final data included responses from 100 dental post-graduates in various dental colleges in Chennai, Tamil Nadu.

DISCUSSION

In the Indian perspective, production, marketing, and distribution of FDCs are governed by the Drugs and Cosmetics Act of 1940, specifically the Drugs and Cosmetics Regulations of 1945.^[7] The Central Drugs Standard Control Organisation (CDSCO) has been given the authority to oversee the FDCs. CDSCO has classified FDCs into four different groups. Group 1: FDCs that have one or more active ingredients and are considered a new drug; the drug development process must be similar to that of a new drug. Group 2: The FDC should have the potential to prove significant pharmacokinetic and pharmacodynamic benefit. Group 3: The ratio of active ingredients in the FDCs is changed/intended for other therapeutic use, whereas in this scenario, rationality is based on pharmacological data. Group 4: Cases in which individual active ingredients have been used for several years were then made into FDCs for convenience (permission can be given based on the pharmacokinetic and pharmacodynamic interaction).^[8] The list of rational and irrational combinations is tabulated in Tables 3 and 4.

Adverse drug reactions (ADRs) are always accompanied by drug usage, especially when drugs are combined irrationally in FDCs. It is astounding to find thousands of such FDCs being regularly marketed and prescribed in India presently.^[9] Khjauria et.al., conducted a cross-sectional, retrospective study over a period of 2 years to assess the profile of ADR contributed by FDCs, with a suspected ADR data collection form used under the Pharmacovigiliance Programme of India. During the 2-year study period, a total of 2,242 adverse drug reactions (ADRs) were documented, with 589 (26.27%) of those ADRs being caused by drug combinations. The most common issues associated with FDCs were lack of individual dose flexibility and increased risk of antimicrobial resistance.^[10] To restrict the irrational use of FDC in India, a multistep approach involving consumers, physicians, regulatory authority, industry, and academicians is required. Typically, dentists in dental college would prescribe antibiotics and painkillers as part of their standard practice to help patients who are experiencing dental discomfort. Unfortunately, there are a lot of irrational FDCs in the market. Adverse drug reactions may occur if these medications are prescribed without proper information, so dental professionals must possess adequate knowledge and upgradation regarding FDCs.^[11] This study was therefore planned to assess the knowledge and attitude of dental post-graduates on commonly prescribed FDCs in dental practice and their perspective regarding the rationality of combinations.

On assessing the knowledge aspect of the respondents on FDCs rationality, 48% stated that FDCs are rational when they meet all three criteria (act by diverse mechanism, kinetics and dynamics should not vary widely, and should not possess adverse side effects), 67% believe that FDCs improve the patient compliance and the majority of the respondent’s perception is FDCs enhances the therapeutic effect and prevents the accomplishment of resistance [Table 3].

In a study conducted by Goswami et al. and Sharma et al., none of the post-graduates could name a single band FDC in India^[12-14], whereas in our study, dental post-graduates had a good knowledge regarding principles of drug combination and its advantages and disadvantages. In questions assessing their knowledge regarding the rationality of commonly prescribed FDCs in dentistry, the majority of the respondents had confusion about the following combinations, whether they are rational/irrational (norfloxacin + metronidazole, pantoprazole + domperidone, and immunosuppressive + corticosteroids) [Table 3]. ^[4,15-18]

Most frequent response by the students regarding source of information on fixed dose combinations was from dental and medical journals, followed by medical representatives, and the least common was from textbooks. When the participants were asked to suggest an intervention to reduce the irrational use of FDCs, most of them suggested devising a new curriculum including the rational drug use and the essential medicine list by DCI. This shows the need for a new curriculum to include FDC at the post-graduate level. A multistep strategy is needed to eliminate the widespread usage of irrational FDCs.

CONCLUSION

We observed that dental postgraduates had good knowledge about FDC’s advantages, disadvantages, and principles of rational combination, but had confusion regarding rationality for some drug combinations. Most dental post-graduates turned towards journals to determine the validity of any FDC, viewing them as an authentic source; yet, it is rare to discover pertinent papers on the subject in reputable journals. Additionally, textbooks ranked last when it came to what made FDCs reasonable, which was a surprise given that textbooks are the only place where one can find the most knowledge at once. Thus, DCI should take necessary steps to include rational drug use, the essential medicine list by WHO, in the curriculum for dental graduates.