Antibiotic prescription: An oral physician's point of view.

BACKGROUND: Antibiotics are important in the management and prophylaxis of infections in patients at a risk of experiencing microbial disease. Uses of systemic antibiotics in dentistry are limited since management of acute dental conditions is primarily based upon extraction of teeth or extirpation of the pulp. However, the literature provides evidence of inappropriate prescribing practices by practitioners, due to a number of factors from inadequate knowledge to social factors. AIM: The aim was to assess the therapeutic prescription of antibiotics in the dental office.
MATERIALS AND METHODS: In the current study, 42 faculty members of two dental colleges in the same vicinity were included. A questionnaire was drafted and sent to the dentists to collect data pertaining to the conditions in which antibiotics were prescribed and most commonly prescribed antibiotic.
RESULTS: During the study period, 42 faculty members from various departments in the institutes were surveyed, of which 41 questionnaires were completely filled. Amoxicillin was the most commonly prescribed antibiotic followed by other amoxicillin combinations; Metronidazole was most widely prescribed antibiotic for anaerobic infections.
CONCLUSION: We have entered an era where cures may be few due to increasing microbial resistance. The biggest force for change will be if all practicing dentists looked at their prescribing and made it more rational.

The most effective way to manage pain of dental or oral origin is to remove the underlying cause. The ‘3-Ds’ should be used to manage dental pain, namely: Diagnosis, drug (if required), and dental treatment. The rationale use of antimicrobials is based upon three variables: A defined indication, the appropriateness of the antimicrobial and adverse effects associated with the drug.

There are very few indications for antimicrobials in dentistry, and they should be judicially used.[1] In the absence of signs and symptoms of infections, practitioners should refrain from prescribing antibiotics for relieving pain. Nobody can deny the value of antibiotics in the management of orofacial infections. But it should be kept in mind that it is to be used as an adjunct and not a substitute for a definite treatment.[2] Much of the pressure to prescribe comes from patient pressure, the fear of medical litigation or just simply poor clinical decision making.[3]

An antibiotic is a chemical produced by a microorganism that kills or inhibits the growth of another microorganism.

The word antibiotic came from the word antibiosis a term coined in 1889 by Louis Pasteur's pupil Paul Vuillemin, which means the process by which life could be used to destroy life. Selman Waksman suggested the word “antibiotic” (coined in 1889 by P. Vuillemin).

1928 penicillin discovered by Fleming

1932 sulfonamide antimicrobial effect by Ehrlich

1943 drug companies begin mass production of penicillin

1948 emergence of cephalosporin precursors

1952 erythromycin derived from Streptomyces erythreus

1956 vancomycin introduced for penicillin-resistant Staphylococcus

1962 quinolone antibiotics first discovered

1970s linezolide discovered but not pursued

1980s fluorinated quinolones introduced, making then clinically useful

2000 Linezolide introduced into clinical practice [Figure 1a].

Figure 1

(a) Classification of antibiotics; (b) Mechanism of action of antibiotics on micro-organisms

Mechanism of actions of antibiotics [Figure 1b]:

Problems that arise with the use of antibiotics:

Toxicity

Hypersensitivity

Drug

Resistance

Super infections

Nutritional

Deficiencies

Masking of an infection.

The aim of the study was to assess the therapeutic prescription of antibiotics in the dental office [Table 1].

Table 1

Some commonly prescribed antibiotics

Materials and Methods

In the current study, 42 faculty members of two dental colleges in the same vicinity were included. A questionnaire [Table 2] was drafted and sent to the dentists to collect data pertaining to the conditions in which antibiotics wereprescribed and most commonly prescribed antibiotic.

Table 2

The questionnaire handed over to dentists during the survey

Results

During the study period, 42 faculty members from various departments in the institutes were surveyed; of which 41 questionnaires were completely filled.

The data were put together and analyzed [Table 3].

Table 3

% of dentists prescribing antibiotics in various dental conditions

Amoxicillin was the most commonly prescribed antibiotic followed by other amoxicillin combinations; metronidazole was most widely prescribed antibiotic for anaerobic infections [Figure 2a and b].

Figure 2

(a) Graphical representation depicting the use of antibiotics in various dental conditions. (b) Graphical representation showing most commonly prescribed antibiotic

Discussion

Ninety-eight percent of the questionnaires returned were completed. To encourage cooperation with data collection, the questionnaire was designed to be brief and easy to complete. Most oral diseases presented to the dentist are primarily inflammatory conditions that are associated with pain. A considerable percentage of dental pain originates from acute and chronic infections of pulpal origin, which necessitates operative intervention, rather than antibiotics.

Many of the dentists prescribed antibiotics for pulpitis, but pulpitis is inflammatory in nature and local treatment only could have removed and relieved the pain and infection.

Pulpitis cannot be treated with antimicrobials. The pulp of a tooth is enclosed in a “closed box” and is becoming necrotic, antimicrobials cannot penetrate or be effective in such a situation; despite this, and they are often prescribed without other interventions.[4] Acute or chronic pulpitis can be treated successfully by either endodontic therapy or exodontia; antimicrobials are not required or indicated.

Some dentists prescribed antibiotics for abscess. When the periapical tissues become involved, and an abscess is formed the treatment is drainage either by exodontia or simple excision. If antimicrobials are used, they are an adjunct to the treatment and are used to limit swelling and also prevent metastasis of the infection to vital organs.

Chronic inflammatory periodontal conditions are also not indicated for antibiotics; systemic antimicrobials should only be used in periodontal conditions where drainage or debridement is impossible, where there is local spread of the infection or where systemic upset has occurred.[5]

Submicrobial dose of doxycycline is widely used in periodontal therapy as an adjunct to mechanical therapy, although resistance is not reported if taken for a short period but there are studies which have reported doxycycline resistance if SDD is prescribed for prolonged periods.

In 1998, the Standing Medical Advisory Committee published The Path of Least Resistance. In it, it stated that dentists account for 7% of all community prescriptions of antimicrobials.[6]

The major concern of superfluous usage of antibiotics is the emerging resistant strains of microorganisms. Microbial resistance refers to the unresponsiveness of microorganism to an antimicrobial agent.[7]

Resistance to amoxicillin, penicillin, and metronidazole in the oral flora has been reported.

Aminopenicillins are one of the three antibiotic types most commonly prescribed in dentistry. Amoxicillin resistance has been described in Veillonella spp. and Prevotella denticola isolated from root canals.[8] In one study, all 34 strains of facultative anaerobic bacteria isolated from the same root canals were susceptible to amoxicillin, as were 52 of 54 (96%) strains of obligate anaerobes.

In 1986, streptococci producing β-lactamase were isolated from the subgingival plaque of adults with periodontitis. Potgieter et al. report four blood culture isolates of Streptococcus mitis that were resistant to penicillin (minimum inhibitory concentrations 16–32 mg/L); they were also resistant to the aminoglycosides gentamicin, kanamycin, and tobramycin. Streptococcus mutans is cariogenic, and several studies have reported on its susceptibility to penicillin and other antimicrobials.

Roche and Yoshimori found that eight out of 97 isolates from odontogenic abscesses were resistant to metronidazole. These included five isolates of Lactobacillus spp., two isolates of Gemella morbillorum and an isolate of Actinomyces israelii.[9]

Resistance may be developed by:

Resistant organisms can be drug tolerant, drug destroying, drug impermeable or rapid ejection of drug [Figure 3a and b].

Figure 3

(a) Pathways by which micro-organisms show resistance to antibiotics. (b) Mechanisms by which micro-organisms exhibit resistance. (c) Factors promoting antimicrobial resistance

Alternatives to conventional antibiotics are:

Resistance-modifying agents

Phage therapy

Bacteriocins

Biotherapy

Vaccines

Chelation

Probiotics

Antisense agents

Broad spectrum antibiotics from plants and animals.

Factors promoting antimicrobial resistance:

Exposure to suboptimal levels of microorganisms.

Exposure to microbes carrying resistant genes.[1011]

Prolonged period of drug regimen [Figure 3c].

How can we combat antimicrobial resistance?

Speedy development of new antibiotics.

Track resistance data nationwide.

Restrict antimicrobial use.

Use narrower spectrum antibiotics (by conducting sensitivity tests).

Use antimicrobial cocktails.[7]

What are sensitivity tests?

A laboratory test which determines how effective antibiotic therapy is against bacterial infections.

Various types of sensitivity tests:

Kirby–Bauer test [Figure 4a]

Figure 4

(a) Kirby-Bauer Test, most commonly used antibiotic sensitivity test. (b) E-Test, a type of antibiotic sensitivity test

E-test [Figure 4b].

Selection of antibiotic prescription:

The clinician should first determine whether antimicrobial therapy is warranted for a given patient. The following things are kept in mind before prescribing antibiotics:

Is an antimicrobial agent indicated on the basis of clinical findings? Or is it prudent to wait until such clinical findings become apparent?

Have appropriate clinical specimens been obtained to establish a microbiological diagnosis?

What are the likely etiological agents for the patient's illness?

Is there clinical evidence that antimicrobial therapy will confer clinical benefit for the patient?

Once a specific cause is identified based on specific microbiologic tests, the following further criteria may be considered:

If a specific microbial pathogen is identified, can a narrower spectrum agent be substituted for the initial empiric drug?

Is one agent or combination of agent necessary?

What are the optimal dose, route of administration, and duration of drug therapy?

What specific tests should be undertaken if the patient is nonresponsive to empirical treatment?

What adjunctive measures can be undertaken to eradicate the infection.[10121314]

Conclusion

Antibiotics are superfluously used in nonindicated clinical cases.

Limit injudicious use of antibiotics.

Superfluous and injudicious use of antibiotics can be prevented by,

Using it as an adjunct and not alone as a treatment option

Using antibiotic sensitivity tests and using infection specific antibiotics

Using narrow spectrum antibiotics.

Limit prophylactic antibiotic prescription

Prescribing antibiotics as prophylaxis is a subject of debate. Limiting prophylactic antibiotic prescription in healthy individuals with those having no underlying systemic diseases or no immunocompromised conditions is recommended.

We have entered an era where cures may be few due to increasing microbial resistance.

The biggest force for change will be if all practicing dentists looked at their prescribing and made it more rational.