Ali H. J. Khekan
MSc Prosthodontics, Department of Dentistry, Al-Mustaqbal University College, Iraq
Abstract
Background : Chlorhexidine gluconate is a broad-spectrum antiseptic agent commonly prescribed in dental practice for managing plaque-induced gingivitis, post-surgical oral hygiene, and certain periodontal conditions. Despite its effectiveness, the irrational and frequent prescription of Chlorhexidine mouthwash, particularly in the absence of clear clinical indications, poses significant concerns regarding patient safety, emergence of antimicrobial resistance, and unnecessary financial burden. General dental practitioners (GDPs), who play a critical role in prescribing habits, often vary in their level of awareness regarding evidence-based indications, dosage regimens, side effects, and duration of use. The present study aimed to assess the level of knowledge, awareness, and clinical practices among GDPs in Babylon Province, Iraq, regarding the rational use of Chlorhexidine mouthwash, and to identify existing knowledge gaps that may lead to inappropriate or over prescription. such as tooth staining, taste alteration, and mucosal desquamation. Over 60% of GDPs reported prescribing Chlorhexidine for non-indicated procedures such as simple extractions or scaling in healthy individuals. Additionally, less than 30% reported awareness of resistance development associated with prolonged or unnecessary use.
Introduction
Chlorhexidine gluconate is an antiseptic agent with broad-spectrum efficacy against Gram-positive and Gram-negative bacteria, fungi, and some viruses. Its use in dentistry is well-documented, particularly for short-term management of plaque control, gingival inflammation, and as a postoperative adjunct to mechanical debridement. Introduced in the 1950s, Chlorhexidine has become a cornerstone in dental antimicrobial protocols due to its substantively and relatively low systemic toxicity (1,2). However, over the decades, growing concerns have emerged regarding its inappropriate use, unnecessary prescription, and adverse effects—especially when used indiscriminately by general dental practitioners (GDPs) without clear clinical justification (3,4).
In daily clinical practice, GDPs often prescribe Chlorhexidine as a preventive or therapeutic mouthwash, not always aligned with the guidelines issued by national or international dental health authorities. Studies have shown that dentists may rely more on anecdotal experience, patient demand, or commercial promotion rather than on evidence-based indications, leading to its misuse (5,6). The routine prescription of Chlorhexidine, especially in cases where local interventions are sufficient (such as uncomplicated scaling, extraction, or minor soft-tissue trauma), contributes not only to unnecessary healthcare costs but also to emerging antimicrobial resistance patterns and alteration of the oral microbiota (7,8).
The adverse effects of long-term or irrational use of Chlorhexidine are well documented. These include extrinsic tooth staining, taste disturbances (dysgeusia), burning sensations, mucosal irritation, and in rare instances, hypersensitivity reactions (9). Additionally, emerging research has pointed toward bacterial resistance mechanisms that may be induced with prolonged Chlorhexidine exposure, including efflux pump activation and cross-resistance to systemic antibiotics (10). In light of the global emphasis on antimicrobial stewardship, such findings warrant a more cautious and rational approach to prescribing antiseptic agents in dental settings(11).
Rational prescribing entails the right drug, at the correct dose, for the appropriate duration, and only when clinically indicated. Evidence suggests that GDPs often deviate from this principle in their day-to-day practice, either due to insufficient pharmacological knowledge or gaps in continuing education (12). For example, Chlorhexidine mouthwash should be limited to cases such as postoperative care following periodontal surgery, in high-risk caries patients, during acute necrotizing periodontal infections, or in patients with compromised manual dexterity (13). It is not recommended as a routine adjunct in healthy individuals undergoing prophylaxis or scaling without underlying disease.
In Iraq, where public health awareness and clinical resources may vary regionally, little published data exists evaluating the awareness of GDPs regarding Chlorhexidine use. The present study addresses this gap by exploring the prescribing behaviors and knowledge level of GDPs in Babylon Province. By identifying trends in over prescription, misperceptions about clinical indications, and lack of awareness of potential complications, this study aims to inform future interventions and guidelines that promote responsible use of antimicrobial oral agents in dental practice.
Allergy, and Resistance Concerns in Dental Use of Chlorhexidine and Associated Agents
1. Drug Interactions in Dental Practice:
In dental settings, several commonly prescribed medications, including antibiotics and antiseptic agents like Chlorhexidine, may interact adversely with other systemic drugs. These interactions can potentiate side effects or reduce therapeutic efficacy, thereby placing patients at risk. Awareness of such interactions is essential for general dental practitioners (GDPs) to ensure patient safety and effective treatment outcomes.
• Amoxicillin and Aspirin: Co-administration can lead to reduced metabolism of aspirin due to modulation of intestinal microflora, thereby increasing the risk of gastrointestinal irritation and other adverse effects (14).
• Amoxicillin/Clavulanate and Warfarin: Though rare, this combination may potentiate warfarin's anticoagulant effect, increasing INR (International Normalized Ratio) and bleeding risk, which may become life-threatening (15).
• Metronidazole and Alcohol: Metronidazole inhibits aldehyde dehydrogenase, leading to accumulation of acetaldehyde. This causes a disulfiram-like reaction characterized by flushing, palpitations, nausea, headache, and vomiting. Patients should be advised to avoid alcohol consumption during and for at least 72 hours after the completion of metronidazole therapy.
• Metronidazole and Lithium: Metronidazole reduces renal excretion of lithium, which may lead to lithium toxicity. Symptoms include tremors, confusion, ataxia, and renal dysfunction. Monitoring of lithium levels is advised when co-prescribed.
• Erythromycin and Digoxin: Erythromycin can suppress gut flora, specifically Eubacterium lentum, which metabolizes oral digoxin in approximately 10% of patients. This may result in elevated digoxin levels, leading to toxicity characterized by nausea, visual disturbances, and arrhythmias.
• Erythromycin, Clarithromycin, and Warfarin: These macrolides inhibit warfarin metabolism, enhancing its anticoagulant effect. Clinical signs include easy bruising, hematuria, and hematoma formation. INR should be monitored closely.
• Antibiotics and Oral Contraceptives: Antibiotics such as penicillin, cephalosporin, erythromycin, clarithromycin, tetracycline, and metronidazole can impair enterohepatic recirculation of estrogen, potentially reducing the efficacy of combined oral contraceptives and resulting in unintended pregnancy (16). Dentists should advise patients to use additional contraceptive measures during antibiotic therapy.
2. Chlorhexidine Allergy Considerations:
Chlorhexidine, though generally well tolerated, may cause hypersensitivity reactions in some patients. Dental practitioners must obtain a detailed medical and allergy history prior to its use. Symptoms of hypersensitivity can range from localized urticaria to systemic anaphylaxis. Although Chlorhexidine allergy is relatively rare, its clinical implications are serious and necessitate prompt discontinuation and appropriate emergency management (17).
Patients allergic to penicillin may also have a cross-allergy to cephalosporin (estimated in 10–15% of cases, particularly in those with a history of anaphylaxis). In such situations, clindamycin is commonly recommended as an alternative antibiotic due to its effective anaerobic coverage and good bone penetration.
3. Concerns About Chlorhexidine Resistance:
Antibiotic resistance has become one of the foremost global health challenges. While Chlorhexidine is not an antibiotic per se, its widespread and often inappropriate use in dental and medical practices has been linked to the emergence of resistance among oral microorganisms (18). Resistance to antiseptics like Chlorhexidine may occur through various mechanisms, such as:
• Alteration in bacterial membrane permeability,
• Efflux pump activation,
• Cross-resistance with systemic antibiotics.
According to the WHO, antimicrobial resistance causes approximately 70,000 deaths annually, a number projected to increase significantly unless stringent antibiotic stewardship measures are implemented(19).
General dental practitioners contribute substantially to community-level antimicrobial resistance due to the high rate of empiric and sometimes unnecessary prescriptions. Studies indicate that 30–50% of antibiotics prescribed by dentists are either unnecessary or incorrectly dosed (20). Notably, many of these prescriptions are issued for conditions that do not require systemic antimicrobial therapy, such as mild gingivitis or uncomplicated extractions.
4. Recommendations for Rational Chlorhexidine and Antibiotic Use in Dental Practice:
To combat rising resistance and promote patient safety, it is critical that all dental practitioners follow established prescribing guidelines. Recommendations include (21):
1. Restrict use to clearly indicated conditions: Chlorhexidine and antibiotics should only be prescribed as adjuncts to active treatment, not as substitutes for mechanical debridement or surgical intervention.
2. Prefer narrow-spectrum agents: When antibiotics are necessary, narrow-spectrum options aligned with current clinical guidelines should be used to minimize collateral microbial damage.
3. Correct dosage and duration: Prescriptions should adhere to evidence-based dosing regimens to avoid under dosing (risk of resistance) or overdosing (risk of toxicity).
4. Patient education: Dentists must clearly inform patients on the correct usage of prescribed drugs, potential side effects, and the importance of adherence.
Avoid prescriptions on patient demand: If a patient insists on receiving antibiotics or mouthwash without medical justification, practitioners should provide appropriate education rather than comply with non-evidence-based requests .
Survey Instrument and Data Collection Procedure
Data were collected using a validated, self-administered structured questionnaire developed after an extensive literature review (2–5). The questionnaire was adapted from previously published studies on antimicrobial prescribing in dentistry and was modified to include items specific to Chlorhexidine prescription practices.
The final survey consisted of 25 items divided into five domains:
1. Demographic information (age, gender, years of practice, workplace type).
2. Knowledge of Chlorhexidine pharmacology (mechanism of action, concentrations, formulations).
3. Clinical indications and prescription practices (postoperative use, periodontal care, prophylaxis).
4. Awareness of side effects, contraindications, and drug interactions.
5. Attitude toward antimicrobial stewardship and resistance concerns.
The questionnaire was pretested among 20 GDPs not included in the final study to ensure clarity and reliability. Internal consistency was measured using Cronbach’s alpha (α = 0.81), confirming good reliability.
The survey was distributed online via Google Forms, using professional dental networks, emails, and social media groups of the Iraqi Dental Association. To minimize duplicate submissions, each response was linked to a unique email address, and IP tracking was applied. Participants were given three reminders over the four-week study period to improve the response rate.
Results:
Use and Awareness of Chlorhexidine Among Dental Practitioners, out of 233 dentists who completed the survey, 178 were general dental practitioners (GDPs), whose responses were analyzed. The use of Chlorhexidine (CHX) in clinical practice was assessed in terms of indications, concentration, duration, awareness of side effects, interactions, and resistance concerns.
1. Common Indications for Prescribing or Recommending Chlorhexidine:
Among the GDPs surveyed:
• 77.5% (138/178) reported using CHX as an adjunct to mechanical plaque control.
• 65.2% (116/178) prescribed CHX following periodontal procedures (e.g., scaling and root planning).
• 49.4% (88/178) used CHX for post-extraction oral hygiene maintenance.
• 36.5% (65/178) recommended CHX for management of oral ulcers or mucositis.
18.5% (33/178) reported using CHX for pre-procedural rinsing to reduce microbial load.
2. Knowledge of Chlorhexidine Concentrations and Formulations:
• 63.5% (113/178) correctly identified 0.12% or 0.2% CHX as the standard concentration for mouthwash.
• 21.3% (38/178) believed higher concentrations (e.g., 2% or 4%) could be used for oral rinses, which may increase the risk of mucosal irritation.
• 15.2% (27/178) were unsure of the standard concentration.
3. Duration and Frequency of Use:
• Only 58.4% (104/178) of GDPs recommended CHX use for no more than 2 weeks, which aligns with current guidelines to avoid adverse effects.
41.6% (74/178) advised longer use (>2 weeks), increasing the risk of tooth staining, taste alteration, and mucosal irritation.
4. Awareness of Side Effects and Patient Instructions:
When asked about adverse effects and patient counseling:
• 72.5% (129/178) were aware of tooth staining as the most common side effect.
• 57.3% (102/178) recognized taste alteration.
• 39.3% (70/178) acknowledged mucosal burning or desquamation.
However, 22.5% (40/178) admitted they rarely warn patients about potential adverse effects.
5. Knowledge of Drug Interactions Involving Chlorhexidine:
• Only 41.6% (74/178) of GDPs reported being aware of drug interactions involving CHX.
• Notably, 26.4% (47/178) were aware of inactivation of CHX by sodium lauryl sulfate (SLS) in toothpaste, and advised patients to wait at least 30 minutes after brushing before rinsing.
• Very few respondents (<10%) were aware of potential interactions between CHX and certain systemic antibiotics (e.g., amoxicillin, metronidazole) via macrobiotic alterations.
6. Awareness of Chlorhexidine Allergy and Resistance:
• Only 36.0% (64/178) of respondents were aware that Chlorhexidine can cause allergic reactions, including rare anaphylaxis.
Awareness of bacterial resistance to CHX was also low, with just 28.1% (50/178) acknowledging that long-term or excessive use may lead to adaptation of oral flora and reduced antiseptic efficacy (22).
Conclusion:
This study highlights significant gaps in the awareness and prescribing practices of general dental practitioners concerning the use of Chlorhexidine in routine dental practice. While a majority of practitioners are familiar with its common indications—such as in plaque control and postoperative care—a considerable portion lacks adequate knowledge regarding its appropriate duration of use, potential adverse effects, and the risks of resistance and hypersensitivity reactions. Alarmingly, a noteworthy number of practitioners continue to prescribe Chlorhexidine in scenarios where it is not clinically indicated, reflecting a broader issue of irrational prescription patterns in dental care.
These findings underscore the necessity of targeted educational efforts and clinical guidelines to optimize Chlorhexidine use. Over prescription and misuse of antiseptics like Chlorhexidine not only increase the risk of local and systemic side effects (e.g., mucosal irritation, staining, dysgeusia) but also contribute to the broader concern of microbial resistance and adverse drug interactions, particularly when used concurrently with systemic medications.
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