Antibiotic prescribing practices among Norwegian dentists
Hans R. Preus*, Jasim M. Albandar and Per Gjermo *Depattment of Oral Biology, State University of New Yotk at Buffalo, USA, and Department of Periodontology, Dental Faculty, University of Oslo, Oslo, Norway
Preus HR, Albandar JM, Gjermo P: Antibiotic prescribing practices among Norwegian dentists. Scand J Dent Res 1992; 100: 232-5. There is scarce information on antibiotics prescription habits among dentists in general. The present investigation was undertaken to study some patterns of antibiotics prescription among Norwegian dentists. A total of 459 dentists ( « 10% of Norwegian dentists) were randomly selected, and to each was mailed a letter describing the survey, accompanied by a questionnaire about age, type of practice, educational background and pattern of prescription of antibiotics. 78% of the dentists responded to these questions. The results indicate that during a typical week, 32% did not prescribe antibiotics, whereas 5% wrote > 5 prescriptions. The mean weekly number of prescriptions per dentist was 2.04. Periodontists and oral surgeons prescribed antibiotics significantly more often than did general practitioners and other disciplines. In addition, those with research and/or teaching experience seemed to prescribe significantly more often than those without. More than 1/3 ofthe sample indicated that they may prescribe antibiotics when treating periodontal diseases. Compared with other disciplines, periodontists prescribed such drugs significantly more often when treating periodontitis, but significantly less often in acute gingivitis, stomatitis and herpes simplex infections. Moreover, 22% of the dentists might prescribe antibiotics when the patient is in pain, 73 and 38% in cases of abscesses with or without generalized malaise, 2.5% in endodontic therapy, 60%) to prevent general complications, and 68% for prophylactic use if the patient revealed a history of endocarditis. Norwegian dentists are somewhat restrictive in their prescription of antibiotics, but they mostly prescribe the correct drugs for the different conditions.
During the past five decades the various medical professions have experienced a rapid and dramatic increase in the therapeutic use of antibiotics required for the treatment of different infections. The cause and cost of this development has been the introduction and spread of antibiotic-resistant bacteria to man and his environment. Moreover, there has been a buildup of a selective pressure on the microbial populations of certain ecosystems (1) as a response to "nondegradeable antibacterial compounds" in wastewater and sewage from human and animal activity as well as from the use of antibiotics in bioindustry. As the selective pressure spreads within our environment, the probability for selecting resistant clones of pathogenic bacteria within the human ecosystem increases. Dentists have traditionally been exposed to patients showing a variety of bacterial infectious diseases. However, unlike in the medical and the veterinary professions, treatment of the majority of these infections (particularly caries and periodontal diseases) have traditionally been mechanical. Only occasionally has the experienced dentist used antibiotics to cure oral infections (2).
Key words: antimicrobials; chemotherapy; dental practice; periodontal disease. Hans R. Preus, Department of Oral Biology, School of Dental Medicine, Faculty of Health Sciences, Foster Hall, 3435 Main Street, NY 14214, USA. Accepted for publication 1 July 1991.
Recent American surveys have revealed that during the eighties there has been an increase in the percentage of American Academy of Periodontology-associated dentists prescribing antibiotics following, and in lieu of, periodontal surgery. Although the array of different regimens has decreased during those years, there are many still in use (3, 4). Since similar studies from other regions of the world are scarce, these US figures incited the initiation of the present study aiming at describing some patterns of prescription of antibiotics among Norwegian dentists. Material and methods
A random sample of 10% of Norwegian dentists (n = 459) received written questionnaires concerning their age, type of practice, educational background and pattern of prescription of antibiotics in terms of frequency of prescription, type of antibiotic and in which disease situation it was used. In addition each member of the sample received a letter describing the survey, definitions of what was considered to be antimicrobials, chemotherapeu-
Antibiotic prescription habits Table 1
233
Results
Nutnber of weekly antibiotic prescriptions by discipline SD Discipline Mean n 9.5 5.0 Periodontists 35 4.7 Oral surgeons 4.7 26 0.000 P GP 2.3 293 1.5 GP, general practitioners and other disciplines. * F-test.
Frequency of antibiotic prescriptions
Table 2 Number of weekly antibiotic prescriptions by experience in teaehing and/or research Teaching and/or P SD research experience Mean n No 2.9 1.6 236 0.01* Yes 5.6 2.9 118 F-tesl.
tics and antibiotics, and requesting participation as well as granting anonymity. One reminder was forwarded to those participants who did not respond within a deadline. The response rate was 78%. The respondents were grouped in three groups; periodontists (specialists in periodontology), oral surgeons (specialists in oral surgery) and all other dentists. Differences in distribution were tested for significance by the chi-square test, and differences between means by the analysis of variance.
5% of the respondents reported prescribing antibiotics more than five times during a typical week, while 32% did not prescribe at all. The mean weekly prescription rate of antibiotics for the entire sample population was 2.04 (SD 4.05). Periodontists and oral surgeons signed significantly more prescriptions per week than general practitioners (Table 1). A significant relationship was also found between the frequency of weekly prescriptions and if the dentist was, or had been, employed in research and/or education (Table 2). The place of dental education or age of the professional did not significantly influence the weekly prescription frequency, but there was a trend towards more frequent prescriptions among younger members of the profession.
Pattern of antibiotics prescribed by dentists
Control of periodontal infections - When treating periodontal disease, 37.6% responded that they prescribed antibiotics or chemotherapeutics. Significantly more prescriptions were given by periodontists as compared to general practitioners. Prescription of antibiotics when treating periodontal diseases with or without surgery was reported with similar frequencies, 10.5 and 11.3%, respectively.
Table 3 Number of dentists prescribing antibiotics occasionally or more often (yes) when treating acute gingivitis, stomatitis, and herpes simplex, by discipline Acute gingivitis Stomatitis Herpes simplex Yes P Yes P No P No Yes Discipline No 2 4 1 33 34 Periodontists 31 17 8 Oral surgeons 13 18 JJ 0.002* ^^ 0.0001* 0.001* 257 GP 250 266 26 307 46 59 Total 294 318 35 GP, general practitioners and other disciplines. X-test.
Table 4 Number of dentists prescribing antibiotics occasionally or more often (yes) in therapy of pain, and abseesses with or without generalized malaise, by discipline Pain Abscesses without malaise Abscesses with malaise No Yes P Discipline P Yes No Yes No P Periodontists 31 4 8 27 12 23 Oral surgeons 23 3 10 16 4 22 NS* NS* NS* GP 220 72 115 177 80 212 Total 79 274 133 257 220 96 NS, not significant {P>0.Q5). X-test.
234
Preus et al. Table 5
Nttmher of dentists (%) prescribing antibiotics routinely in therapy of abscesses with generalized trialaise (yes), by discipline No Yes % Discipline P 20 Periodontists 28 7 10 61.5 Oral surgeons 16 0.004* 171 41.6 GP 122 41 Total 209 145 GP, general practitioners and other disciplines. * x'-test.
Only one respondent prescribed such drugs routinely when treatment of the periodontal disease included surgery. 13%, 16.7%, and 9.9% of the total population responded that they prescribed antibiotics when treating acute gingivitis, stomatitis and herpes simplex infections, respectively. However, there was a significantly lower prescription frequency among peridontists compared to general practitioners when dealing with these particular infections, while oral surgeons tended to prescribe antibiotics more often (Table 3). Oral infections causing pain or general malaise 22.4% of the respondents reported that they might prescribe antibiotics if the patient was in pain. 37.7% reported prescribing such drugs to patients suffering from abscesses without symptoms of generalized malaise, whereas 72.8% reported such treatment when the patient presented with an abscess including generalized malaise (Table 4). In the latter case more than 40% prescribed antibiotics routinely (Table 5). Endodontics - 2.5% reported often or routine use of antibiotics when performing endodontic therapy. Prophylactic use of antibiotics - 59.8% of the dentists used antibiotics to prevent general complications due to the dental treatment. Of these, 20.3%
reported to prescribe these drugs routinely. In particular, 68.3% prescribed such drugs for prophylactic use if the patient revealed a history of endocarditis. 56%) reported routine prescription whereas 31.7% never prescribed antibiotics in this particular situation. In these different conditions the place of dental education, age of the professional or history of employment in research and/or education did not significantly influence the pattern of antibiotics prescription. Type of antibiotics prescribed by Norwegian dentists
Table 6 displays the prescription rate by disease category and type of antibiotics. The average dentist signed 2.04 prescriptions per week. Based on the most commonly prescribed antibiotics and their prices in Norway, the estimated weekly cost of the prescribed antibiotics per dentist was 65 NoK (approximately 10 US$). With 4000 active dentists and 45 average weeks of labor per dentist, this prescription of antibiotics would result in an annual public expenditure of 12 million NoK (approximately 2 million US$). Discussion The results of this survey indicate that the amount of antibiotics prescribed by Norwegian dentists is limited. Only few dentists prescribe antibiotics on a daily basis. There was also a low spectrum of the prescribed drugs, penicillins, followed by tetracyclines, being the two most commonly prescribed antibiotics for most oral infections. Only oral surgeons used a wide variety of different antibiotics dependent upon the nature and kind of infection to be treated.
Table 6 Number of dentists prescribing antibiotics by disease category and type of antibiotics (n = 358) PeniTetraMycoImidaSpira- Erythro- SulfoDisease category cillins cyclines statica zoles mycin mycin namides Periodontal treatment (without surgery) 27 1 16 Periodontal treatment (with surgery) 28 1 9 Acute gingivitis 37 3 4 2 Pain, toothache t Stomatitis 38 2 17 2 1 Herpes simplex 11 3 1 Abscesses, unaffected general condition 131 4 Abscesses, affected general condition 255 2 To prevent general medical complications 211 1 1 ,. In increased risk of endocarditis 234 3 3 Oral surgery 120 1 1 5 Oral medical treatment 55 4 5 Prosthetics 9 2 13 2 . Maintenance 8 2 Endodontics 112
Others 1 1 15 1 20 1 1 10 3 3
Antibiotic prescription habits In most situations, the majority of dentists used drugs and regimens "correctly" as described in generally accepted textbooks and as lectured in Norwegian dental schools. However, although there is a general recommendation in all these textbooks to use tetracyclines when needed against periodontal diseases, penicillins were the most commonly prescribed drugs by general practitioners and oral surgeons. Periodontists prescribed tetracyclines and less frequently imidazoles. Periodontists and oral surgeons also prescribed antibiotics more frequently than general practitioners. This may be due to the referral habits among Norwegian general practitioners who refer their patients to specialists in an advanced stage of the infection, thus forcing the specialist to take more radical action than would have been necessary had the case been presented at an earlier stage. Another serious shortcoming was revealed as almost 32% of the general practitioners never prescribed antibiotics as prophylaxis when treating patients with a history of endocarditis. These fmdings are similar to those of SADOWSKY et al. (5) reporting that 32% of the dentists in New York state were uncertain about the use of antibiotics in prevention of endocarditis. Furthermore, in the present study penicillins were by far the most prescribed drugs by those responding positively to this question (Table 6). This is unfortunate since endocarditis may be caused by some oral organisms like A. actinomyeetemcomitans strains which are resistant to penicillins (6-8). It should be stressed that the American Heart Association and the American Dental Association recommend amoxycillin as a first choice for prophylaxis when treating patients with a history of endocarditis (9), a view which has also been supported in a recent Scandinavian symposium (10). There are few studies of antibiotics prescription habits of dentists available for comparison with our data. In 1976 PETERSEN et al. (11) reported that Danish dentists mainly prescribed penicillin to their patients, and that there seemed to be an uncertainty among the dentists which chemotherapeutic to chose in cases of penicillin allergy. They were also in doubt about which regimens to use in cases where prophylactic antibiotic treatments were warranted. This is partly in concert with the present findings. Moreover, there are also indications that antibiotics are by far the most pre-
235
scribed drugs in general dental practices in the USA (3), and that American dentists display more varied prescription habits with tetracyclines being the most preferred drugs against periodontal diseases (4). The average weekly prescription frequency for the American dentist for drugs in general was 2.9 prescriptions. Since this includes other drugs such as pain relievers, tranquilizers, ... etc. this would probably be comparable to the weekly prescription frequency of antibiotics by the Norwegian dentist. Based on these findings it may be reasonable to conclude that Norwegian dentists are somewhat restrictive in their prescription of antibiotics, but they mostly prescribe the correct drugs for the different conditions. However, the present study revealed shortcomings in the knowledge ofthe prophylactic use of antibiotics when treating patients with a history of endocarditis, as well as when choosing to treat periodontal diseases with antibiotics as an adjunct.
References 1. LEVY SB. Evolution and spread of tetracycline resistance determinants. J Antimicroh Chemotlier 1989; 24: 1-3. 2. NEWMAN M , KORNMAN K . Antibiotic/antimicrobial use in
dental practice. 1st edn. Chicago; Quintessence Publishing Co., 1990. 3. CiANCio S, REYNARD A, ZIELEZNY M , MATHER M . A survey
of drug prescribing practices of dentists. NYS Dent J 1989; 55: 29-31. 4. CiANCio S. Personal communication, 1991. 5. SADOWSKY D, KUNZEL C . A study of the implementation
of endocarditis prevention in patients at risk. NYS Dent J 1986; 52: 34-7. 6. WALKER CB, PAPPAS JD, TYLER K Z , COHEN S, GORDON
JM. Antibiotic susceptibilities of periodontal bacteria. In vitro susceptibilities to eight antimicrobial agents. J Periodontol 1985; 56: 67-74. 7. SLOTS J, EVANS RT, LOBBINS PM, GENCO RJ. In vitro
antimicrobial susceptibility of Actinobacillus actinomyeetemcomitans. Antimicrob Agents Chemotlier 1980; 18: 9-11. 8. ADNAN S, DAJANI M D , ALAN L, et al. Prevention of bacte-
rial endocarditis. Recommendations by the American Heart Association. JADA 1990; 264: 2919-22. 9. SLOTS J, ROSLING B G , GENCO RJ. Suppression of penicillin-
resistant oral Actinobacillus actinomyeetemcomitans with tetracycline. Consideration in endocarditis prophylaxis. J Periodontol 1983; 54: 193-6. 10. PAUNIO K. Introduction. J Clin Periodontol 1990; 17: 473. 11. PETERSEN J K , PEDERSEN A, PEDERSEN LV, PEDERSEN L H ,
PEDERSEN V D . Tandlaegers ordination af kemoterapeutika. Tandtaegebladet 1976; 80: 469-76.
Hans R. Preus*, Jasim M. Albandar and Per Gjermo *Depattment of Oral Biology, State University of New Yotk at Buffalo, USA, and Department of Periodontology, Dental Faculty, University of Oslo, Oslo, Norway
Preus HR, Albandar JM, Gjermo P: Antibiotic prescribing practices among Norwegian dentists. Scand J Dent Res 1992; 100: 232-5. There is scarce information on antibiotics prescription habits among dentists in general. The present investigation was undertaken to study some patterns of antibiotics prescription among Norwegian dentists. A total of 459 dentists ( « 10% of Norwegian dentists) were randomly selected, and to each was mailed a letter describing the survey, accompanied by a questionnaire about age, type of practice, educational background and pattern of prescription of antibiotics. 78% of the dentists responded to these questions. The results indicate that during a typical week, 32% did not prescribe antibiotics, whereas 5% wrote > 5 prescriptions. The mean weekly number of prescriptions per dentist was 2.04. Periodontists and oral surgeons prescribed antibiotics significantly more often than did general practitioners and other disciplines. In addition, those with research and/or teaching experience seemed to prescribe significantly more often than those without. More than 1/3 ofthe sample indicated that they may prescribe antibiotics when treating periodontal diseases. Compared with other disciplines, periodontists prescribed such drugs significantly more often when treating periodontitis, but significantly less often in acute gingivitis, stomatitis and herpes simplex infections. Moreover, 22% of the dentists might prescribe antibiotics when the patient is in pain, 73 and 38% in cases of abscesses with or without generalized malaise, 2.5% in endodontic therapy, 60%) to prevent general complications, and 68% for prophylactic use if the patient revealed a history of endocarditis. Norwegian dentists are somewhat restrictive in their prescription of antibiotics, but they mostly prescribe the correct drugs for the different conditions.
During the past five decades the various medical professions have experienced a rapid and dramatic increase in the therapeutic use of antibiotics required for the treatment of different infections. The cause and cost of this development has been the introduction and spread of antibiotic-resistant bacteria to man and his environment. Moreover, there has been a buildup of a selective pressure on the microbial populations of certain ecosystems (1) as a response to "nondegradeable antibacterial compounds" in wastewater and sewage from human and animal activity as well as from the use of antibiotics in bioindustry. As the selective pressure spreads within our environment, the probability for selecting resistant clones of pathogenic bacteria within the human ecosystem increases. Dentists have traditionally been exposed to patients showing a variety of bacterial infectious diseases. However, unlike in the medical and the veterinary professions, treatment of the majority of these infections (particularly caries and periodontal diseases) have traditionally been mechanical. Only occasionally has the experienced dentist used antibiotics to cure oral infections (2).
Key words: antimicrobials; chemotherapy; dental practice; periodontal disease. Hans R. Preus, Department of Oral Biology, School of Dental Medicine, Faculty of Health Sciences, Foster Hall, 3435 Main Street, NY 14214, USA. Accepted for publication 1 July 1991.
Recent American surveys have revealed that during the eighties there has been an increase in the percentage of American Academy of Periodontology-associated dentists prescribing antibiotics following, and in lieu of, periodontal surgery. Although the array of different regimens has decreased during those years, there are many still in use (3, 4). Since similar studies from other regions of the world are scarce, these US figures incited the initiation of the present study aiming at describing some patterns of prescription of antibiotics among Norwegian dentists. Material and methods
A random sample of 10% of Norwegian dentists (n = 459) received written questionnaires concerning their age, type of practice, educational background and pattern of prescription of antibiotics in terms of frequency of prescription, type of antibiotic and in which disease situation it was used. In addition each member of the sample received a letter describing the survey, definitions of what was considered to be antimicrobials, chemotherapeu-
Antibiotic prescription habits Table 1
233
Results
Nutnber of weekly antibiotic prescriptions by discipline SD Discipline Mean n 9.5 5.0 Periodontists 35 4.7 Oral surgeons 4.7 26 0.000 P GP 2.3 293 1.5 GP, general practitioners and other disciplines. * F-test.
Frequency of antibiotic prescriptions
Table 2 Number of weekly antibiotic prescriptions by experience in teaehing and/or research Teaching and/or P SD research experience Mean n No 2.9 1.6 236 0.01* Yes 5.6 2.9 118 F-tesl.
tics and antibiotics, and requesting participation as well as granting anonymity. One reminder was forwarded to those participants who did not respond within a deadline. The response rate was 78%. The respondents were grouped in three groups; periodontists (specialists in periodontology), oral surgeons (specialists in oral surgery) and all other dentists. Differences in distribution were tested for significance by the chi-square test, and differences between means by the analysis of variance.
5% of the respondents reported prescribing antibiotics more than five times during a typical week, while 32% did not prescribe at all. The mean weekly prescription rate of antibiotics for the entire sample population was 2.04 (SD 4.05). Periodontists and oral surgeons signed significantly more prescriptions per week than general practitioners (Table 1). A significant relationship was also found between the frequency of weekly prescriptions and if the dentist was, or had been, employed in research and/or education (Table 2). The place of dental education or age of the professional did not significantly influence the weekly prescription frequency, but there was a trend towards more frequent prescriptions among younger members of the profession.
Pattern of antibiotics prescribed by dentists
Control of periodontal infections - When treating periodontal disease, 37.6% responded that they prescribed antibiotics or chemotherapeutics. Significantly more prescriptions were given by periodontists as compared to general practitioners. Prescription of antibiotics when treating periodontal diseases with or without surgery was reported with similar frequencies, 10.5 and 11.3%, respectively.
Table 3 Number of dentists prescribing antibiotics occasionally or more often (yes) when treating acute gingivitis, stomatitis, and herpes simplex, by discipline Acute gingivitis Stomatitis Herpes simplex Yes P Yes P No P No Yes Discipline No 2 4 1 33 34 Periodontists 31 17 8 Oral surgeons 13 18 JJ 0.002* ^^ 0.0001* 0.001* 257 GP 250 266 26 307 46 59 Total 294 318 35 GP, general practitioners and other disciplines. X-test.
Table 4 Number of dentists prescribing antibiotics occasionally or more often (yes) in therapy of pain, and abseesses with or without generalized malaise, by discipline Pain Abscesses without malaise Abscesses with malaise No Yes P Discipline P Yes No Yes No P Periodontists 31 4 8 27 12 23 Oral surgeons 23 3 10 16 4 22 NS* NS* NS* GP 220 72 115 177 80 212 Total 79 274 133 257 220 96 NS, not significant {P>0.Q5). X-test.
234
Preus et al. Table 5
Nttmher of dentists (%) prescribing antibiotics routinely in therapy of abscesses with generalized trialaise (yes), by discipline No Yes % Discipline P 20 Periodontists 28 7 10 61.5 Oral surgeons 16 0.004* 171 41.6 GP 122 41 Total 209 145 GP, general practitioners and other disciplines. * x'-test.
Only one respondent prescribed such drugs routinely when treatment of the periodontal disease included surgery. 13%, 16.7%, and 9.9% of the total population responded that they prescribed antibiotics when treating acute gingivitis, stomatitis and herpes simplex infections, respectively. However, there was a significantly lower prescription frequency among peridontists compared to general practitioners when dealing with these particular infections, while oral surgeons tended to prescribe antibiotics more often (Table 3). Oral infections causing pain or general malaise 22.4% of the respondents reported that they might prescribe antibiotics if the patient was in pain. 37.7% reported prescribing such drugs to patients suffering from abscesses without symptoms of generalized malaise, whereas 72.8% reported such treatment when the patient presented with an abscess including generalized malaise (Table 4). In the latter case more than 40% prescribed antibiotics routinely (Table 5). Endodontics - 2.5% reported often or routine use of antibiotics when performing endodontic therapy. Prophylactic use of antibiotics - 59.8% of the dentists used antibiotics to prevent general complications due to the dental treatment. Of these, 20.3%
reported to prescribe these drugs routinely. In particular, 68.3% prescribed such drugs for prophylactic use if the patient revealed a history of endocarditis. 56%) reported routine prescription whereas 31.7% never prescribed antibiotics in this particular situation. In these different conditions the place of dental education, age of the professional or history of employment in research and/or education did not significantly influence the pattern of antibiotics prescription. Type of antibiotics prescribed by Norwegian dentists
Table 6 displays the prescription rate by disease category and type of antibiotics. The average dentist signed 2.04 prescriptions per week. Based on the most commonly prescribed antibiotics and their prices in Norway, the estimated weekly cost of the prescribed antibiotics per dentist was 65 NoK (approximately 10 US$). With 4000 active dentists and 45 average weeks of labor per dentist, this prescription of antibiotics would result in an annual public expenditure of 12 million NoK (approximately 2 million US$). Discussion The results of this survey indicate that the amount of antibiotics prescribed by Norwegian dentists is limited. Only few dentists prescribe antibiotics on a daily basis. There was also a low spectrum of the prescribed drugs, penicillins, followed by tetracyclines, being the two most commonly prescribed antibiotics for most oral infections. Only oral surgeons used a wide variety of different antibiotics dependent upon the nature and kind of infection to be treated.
Table 6 Number of dentists prescribing antibiotics by disease category and type of antibiotics (n = 358) PeniTetraMycoImidaSpira- Erythro- SulfoDisease category cillins cyclines statica zoles mycin mycin namides Periodontal treatment (without surgery) 27 1 16 Periodontal treatment (with surgery) 28 1 9 Acute gingivitis 37 3 4 2 Pain, toothache t Stomatitis 38 2 17 2 1 Herpes simplex 11 3 1 Abscesses, unaffected general condition 131 4 Abscesses, affected general condition 255 2 To prevent general medical complications 211 1 1 ,. In increased risk of endocarditis 234 3 3 Oral surgery 120 1 1 5 Oral medical treatment 55 4 5 Prosthetics 9 2 13 2 . Maintenance 8 2 Endodontics 112
Others 1 1 15 1 20 1 1 10 3 3
Antibiotic prescription habits In most situations, the majority of dentists used drugs and regimens "correctly" as described in generally accepted textbooks and as lectured in Norwegian dental schools. However, although there is a general recommendation in all these textbooks to use tetracyclines when needed against periodontal diseases, penicillins were the most commonly prescribed drugs by general practitioners and oral surgeons. Periodontists prescribed tetracyclines and less frequently imidazoles. Periodontists and oral surgeons also prescribed antibiotics more frequently than general practitioners. This may be due to the referral habits among Norwegian general practitioners who refer their patients to specialists in an advanced stage of the infection, thus forcing the specialist to take more radical action than would have been necessary had the case been presented at an earlier stage. Another serious shortcoming was revealed as almost 32% of the general practitioners never prescribed antibiotics as prophylaxis when treating patients with a history of endocarditis. These fmdings are similar to those of SADOWSKY et al. (5) reporting that 32% of the dentists in New York state were uncertain about the use of antibiotics in prevention of endocarditis. Furthermore, in the present study penicillins were by far the most prescribed drugs by those responding positively to this question (Table 6). This is unfortunate since endocarditis may be caused by some oral organisms like A. actinomyeetemcomitans strains which are resistant to penicillins (6-8). It should be stressed that the American Heart Association and the American Dental Association recommend amoxycillin as a first choice for prophylaxis when treating patients with a history of endocarditis (9), a view which has also been supported in a recent Scandinavian symposium (10). There are few studies of antibiotics prescription habits of dentists available for comparison with our data. In 1976 PETERSEN et al. (11) reported that Danish dentists mainly prescribed penicillin to their patients, and that there seemed to be an uncertainty among the dentists which chemotherapeutic to chose in cases of penicillin allergy. They were also in doubt about which regimens to use in cases where prophylactic antibiotic treatments were warranted. This is partly in concert with the present findings. Moreover, there are also indications that antibiotics are by far the most pre-
235
scribed drugs in general dental practices in the USA (3), and that American dentists display more varied prescription habits with tetracyclines being the most preferred drugs against periodontal diseases (4). The average weekly prescription frequency for the American dentist for drugs in general was 2.9 prescriptions. Since this includes other drugs such as pain relievers, tranquilizers, ... etc. this would probably be comparable to the weekly prescription frequency of antibiotics by the Norwegian dentist. Based on these findings it may be reasonable to conclude that Norwegian dentists are somewhat restrictive in their prescription of antibiotics, but they mostly prescribe the correct drugs for the different conditions. However, the present study revealed shortcomings in the knowledge ofthe prophylactic use of antibiotics when treating patients with a history of endocarditis, as well as when choosing to treat periodontal diseases with antibiotics as an adjunct.
References 1. LEVY SB. Evolution and spread of tetracycline resistance determinants. J Antimicroh Chemotlier 1989; 24: 1-3. 2. NEWMAN M , KORNMAN K . Antibiotic/antimicrobial use in
dental practice. 1st edn. Chicago; Quintessence Publishing Co., 1990. 3. CiANCio S, REYNARD A, ZIELEZNY M , MATHER M . A survey
of drug prescribing practices of dentists. NYS Dent J 1989; 55: 29-31. 4. CiANCio S. Personal communication, 1991. 5. SADOWSKY D, KUNZEL C . A study of the implementation
of endocarditis prevention in patients at risk. NYS Dent J 1986; 52: 34-7. 6. WALKER CB, PAPPAS JD, TYLER K Z , COHEN S, GORDON
JM. Antibiotic susceptibilities of periodontal bacteria. In vitro susceptibilities to eight antimicrobial agents. J Periodontol 1985; 56: 67-74. 7. SLOTS J, EVANS RT, LOBBINS PM, GENCO RJ. In vitro
antimicrobial susceptibility of Actinobacillus actinomyeetemcomitans. Antimicrob Agents Chemotlier 1980; 18: 9-11. 8. ADNAN S, DAJANI M D , ALAN L, et al. Prevention of bacte-
rial endocarditis. Recommendations by the American Heart Association. JADA 1990; 264: 2919-22. 9. SLOTS J, ROSLING B G , GENCO RJ. Suppression of penicillin-
resistant oral Actinobacillus actinomyeetemcomitans with tetracycline. Consideration in endocarditis prophylaxis. J Periodontol 1983; 54: 193-6. 10. PAUNIO K. Introduction. J Clin Periodontol 1990; 17: 473. 11. PETERSEN J K , PEDERSEN A, PEDERSEN LV, PEDERSEN L H ,
PEDERSEN V D . Tandlaegers ordination af kemoterapeutika. Tandtaegebladet 1976; 80: 469-76.
