Antibiotics and oral contraceptives: new considerations for dental practice
changes in advice that should be given to
VERIFIABLE CPD PAPER
The aim of this paper is to highlight a change in guidance relating to possible interactions between antibiotics and oral contraceptives. Until recently, dentists have been advised to warn women taking the combined oral contraceptive pill of the routine need to use additional contraceptive measures while taking courses of broad spectrum antibiotics. Recent guid-ance relating to this issue has changed and dentists may not be aware of this. This paper reminds dentists of the previous guidelines and related evidence, reviews the pharmacokinetics of hormonal contraception and presents them with the latest evidence-based guidance. This should change their clinical practice. CLINICAL SCENARIO
prescribed to them may interfere with the
contraceptive effects of the combined oral
contraceptive pill and that additional con-
tal periapical infection associated with traceptive methods should be used while
the upper left first premolar. You obtain taking the antibiotics and for seven days
contraception is available as an oral pill,
drainage by accessing the root canal, after stopping.1 This advice was based on
however, due to the facial swelling and our understanding at the time and further
oral pills may be taken on a 21 day cycle
the patient’s associated malaise and publications reminded dentists of their with a 7 day break or taken continuously. reported pyrexia, you prescribe 500 mg professional obligations in this area and The progestogen-only contraceptive is amoxicillin to be taken three times a day
the possible medico-legal implications of
available as an oral pill, an intramuscu-
for five days. Her medical history reveals
not following current guidance.2 Various
she is taking the contraceptive pill. What
mechanisms for delivering the advice to terine device. The progestogen-only oral
patients, including a patient information
pills are taken on a continuous basis and
PREVIOUS RECOMMENDATIONS HORMONAL CONTRACEPTION
trial lining. They are usually used when
nario faced by dentists on a daily basis There are two main types of hormonal oestrogens are contra-indicated. and has been for many years. In 1994, contraception. These are the combined
the British Dental Journal published a hormonal contraceptive and the pro-
paper reviewing the possible interactions
gestogen-only contraceptive. Combined combined oral contraceptive in the UK.3
tives emphasising the need for dentists to
trogen and a progestogen component. according to instructions.4
follow current national guidelines as part
Factors affecting the reliability of oral
of good dental practice.1 At the time the gestogen is fixed they are know as ‘mono-
guidance was that as a dentist you needed
phasic’. When the amount of hormone 1. Diarrhoea and vomiting: vomiting
to warn the patient that the antibiotics varies according to the stage of cycle,
they are known as ‘phasic.’ The oestro-
gen component is usually ethinylestradiol
Specialist Registrar in Oral Medicine; 2Consultant in
Oral Medicine, Department of Oral Medicine, University
Dental Hospital of Manchester, Higher Cambridge
Refereed Paper Accepted 15 March 2012 DOI: 10.1038/sj.bdj.2012.414 British Dental Journal 2012; 212: 481-483 BRITISH DENTAL JOURNAL VOLUME 212 NO. 10 MAY 26 2012
2012 Macmillan Publishers Limited. All rights reserved.
PRACTICE Table 1 Enzyme-inducing and non-enzyme-inducing antibiotics
illness and for a period of time after recovery5
Enzyme-inducing antibiotics Non-enzyme-inducing antibiotics
component. Oral ethinylestradiol is absorbed from the small intestine
in the British Dental Journal in 2011
Absorption
antibacterial drugs prescribed by dentists
in Wales. Other antimicrobials prescribed
included clindamycin, macrolides and tet-
racyclines.9 In dentistry, enzyme-inducing
Metabolism (first pass)
antibiotics appear to be only very rarely
used if at all, hence interactions of com-
inducing antibiotics is unlikely to be a
The most important hepatic enzyme is cytochrome p-450 mixed function
CURRENT RECOMMENDATIONS Large Intestine ENTEROHEPATIC CIRCULATION
ics. Several studies and trials have looked
at levels of ethinylestradiol in patients
rifabutin) are the only antibiotics that
pill (COCP) and antibiotics and have not
found decreased levels of ethinylestradiol
Medical eligibility criteria for contracep-Fig. 1 Metabolism of oral contraceptives tive use in 2010 to include evidence-based CONCLUSION
interactions.14 On the basis of this, in The recent change in the evidence base
January 2011 the Clinical Effectiveness has implications for dentistry. When pre-
Unit of the Faculty of Sexual and scribing non-enzyme-inducing antibiot-
Reproductive Healthcare (Royal College ics to patients using combined hormonal
of Obstetricians and Gynaecologists) contraception, the current guidance is that
produced new clinical guidance which there is now no need to tell patients that
now states that ‘additional contracep-
they should use additional contraceptive
tive precautions are not required even methods while they take the antibiotics.
for short courses of antibiotics that For patients on any form of oral contra-
are not enzyme inducers when taken ception, however, the guidance remains
with combined oral contraception’.6
that they should be aware that additional
This new advice has been incorporated contraceptive precautions are needed
into the guidance given in the British should they suffer diarrhoea or vomiting National Formulary.5
as a result of their illness or as a side effect
ANTIBIOTICS AND DENTISTRY
If the antibiotics (or indeed the illness) of the antibiotics.
In 2010, general dental practitioners in should cause diarrhoea or vomiting, then
England prescribed over 3.8 million items
the usual additional precautions relating to
under the infections chapter of the British
these conditions should be observed.
implications for dental practitioners. BRITISH DENTAL JOURNAL VOLUME 212 NO. 10 MAY 26 2012
2012 Macmillan Publishers Limited. All rights reserved.
PRACTICE
1. Gibson J, McGowan D A. Oral contraceptives and
clinical guidance: drug interactions with hormonal
11. Abrams L S, Skee D M, Natarajan J, Hutman W,
antibiotics: important considerations for dental
contraception. London: Royal College of
Wong F A. Tetracycline HCL does not affect the
practice. Br Dent J 1994; 177: 419–422.
Obstetricians and Gynaecologists, 2011.
pharmakokinetics of a contraceptive patch. Int J
2. Stephens I F, Binnie V I, Kinane D F. Dentists, pills
7. Seymour R A. Drug interactions in dentistry Dent Gynaecol Obstet 2000; 70: 57–58.
and pregnancies. Br Dent J 1996; 181: 236–239. Update 2009; 36: 458–460, 463–436, 469–470.
12. Neely J L, Abate M, Swinker M, D’Angio R. The effect
3. The Office for National Statistics. Contraception
8. The NHS Information Centre, Dental and Eye
of doxycycline on serum levels of ethinylestradiol,
and sexual health, 2005-06. London: ONS, 2006.
Care Team, Prescribing Support Unit. Prescribing
norethindrone, and endogenous progesterone.
Online article available at http://www.ons.gov. by dentists, 2010. England: NHS Information
Obstet Gynecol 1991; 77: 416–420.
uk/ons/rel/lifestyles/contraception-and-sexual-
13. Dogterom P, van den Heuvel M W, Thomson T.
health/2005-06/index.html (accessed March 2012).
9. Karki A J, Holyfield G, Thomas D. Dental prescribing
Absence of pharmacokinetic interactions of the
4. Family Planning Association. Online information
in Wales and associated public health issues.
combined contraceptive vaginal ring Nuvaring with
available at www.fpa.org.uk (accessed March 2012). Br Dent J 2011; 210: E21.
oral amoxicillin or doxycycline in two randomised
British National Formulary 61. London:
10. Murphy A A, Zacur H A, Charace P, Burkman
trials. Clin Pharmacokinet 2005; 44: 429–438.
R T. The effect of tetracycline on levels of oral
14. World Health Organization. Medical eligibility
6. Faculty of Sexual and Reproductive Healthcare.
contraceptives. Am J Obstet Gynecol 1991;
criteria for contraceptive use, 4th ed. Geneva:
Faculty of Sexual and Reproductive Healthcare 164: 28–33.
Erratum Obituary (BDJ 2012; 212: 399) ‘Peter Douglas Bird’In the above obituary, the author’s name should have read as follows:John R. DaveyWe apologise for any misunderstanding caused. BRITISH DENTAL JOURNAL VOLUME 212 NO. 10 MAY 26 2012
2012 Macmillan Publishers Limited. All rights reserved.
MICROLASERPEELTM Jason N. Pozner, M.D. 4800 North Federal HighwaySuite C101Boca Raton, Florida [email protected](561) 367-9101Fax (561) 367-9102 University of Miami School of Medicine and Boca Raton, Florida Presented in part at the American Society for Lasers in Medicine and Surgery Annual Key Words: Laser Resurfacing, Facial Rejuvenation, Erbium Laser Abstract Backgrou