Antibiotic Prophylaxis

• Dental procedures under local or no anaesthesia.
  • This includes extractions, scaling, and surgery involving gingival tissues.
  • Patients who have not received a single dose of penicillin in the previous month (e.g. during multistage treatment), including those with a prosthetic valve (but excluding those who have had endocarditis), should have oral amoxicillin 3 g 1 hour before procedure
  • Children under 5 years should have a quarter adult dose, and 5-10 years half the adult dose.¹ Patients who are penicillin-allergic or have received more than a single dose of a penicillin in the previous month, oral clindamycin is recommended 600 mg 1 hour before procedure.
  • Children under 5 years should have clindamycin 150 mg or azithromycin 200 mg.
  • Those between 5-10 years should be given clindamycin 300 mg or azithromycin 300 mg.
  • For multistage procedures a maximum of 2 single doses of a penicillin may be given in a month; alternative drugs should be used for further treatment and the penicillin should not be used again for 3-4 months.²
  • If clindamycin is used, it should not be repeated at intervals of less than two weeks for periodontal or other multistage procedures. Clindamycin is not licensed for use in endocarditis prophylaxis but is endorsed by the Endocarditis Working Party.¹
  • For patients who have had endocarditis, give amoxicillin gentamicin, as per the guidance for general anaesthesia.
• Dental procedures under general anaesthesia.³
  • Patients who do not have a prosthetic valve or who have not had endocarditis, (including patients who have not received more than a single dose of a penicillin in the previous month), should be given i/v amoxicillin 1 g at induction, followed by oral amoxicillin 500 mg 6 hours later.
  • Children under 5 years should be given a quarter of the adult dose, and those under 5-10 years half adult dose.
  • Another option is to give oral amoxicillin 3 g 4 hours before induction then oral amoxicillin 3 g as soon as possible after procedure (child under 5 years quarter adult dose; 5-10 years half adult dose).
  • Special risk patients (i.e.those with a prosthetic valve or who have had endocarditis), should be given i/v amoxicillin 1 g plus i/v gentamicin 120 mg at induction, then oral amoxicillin 500 mg 6 hours later. Children under 5 years should be given amoxicillin quarter adult dose, gentamicin 2 mg/kg, and those 5-10 years ,amoxicillin half adult dose, gentamicin 2 mg/kg.
  • Patients allergic to penicillin or who have had a single dose of penicillin in the preceding month should have either i/v vancomycin 1 g over at least 100 minutes then i/v gentamicin 120 mg at induction or 15 minutes before procedure.
  • Children under 10 years should be given vancomycin 20 mg/kg gentamicin 2 mg/kg.
  • Alternatives are i/v teicoplanin 400 mg plus gentamicin 120 mg at induction or 15 minutes before procedure.
  • For children under 14 years give teicoplanin 6 mg/kg plus gentamicin 2 mg/kg or i/v clindamycin 300 mg over at least 10 minutes at induction or 15 minutes before procedure.
  • This should be followed by oral or i/v clindamycin 150 mg 6 hours later (for child under 5 years quarter adult dose; 5-10 years half adult dose).
  • The situation regarding dental procedures and antibiotic prophylaxis is controversial subject. The lack of evidence to support guidelines has been questioned, and a Cochrane review advises clinicians to discuss the pros and cons of antibiotic prophylaxis with patients before prescribing.⁴

• The World Health Organisation (WHO) recommend secondary prophylaxis with oral phenoxymethylpenicillin 250 mg twice daily or sulfadiazine 1 g daily (500 mg daily for patients under 30 kg).^2,6
• However, a Cochrane meta-analysis suggests that two- or three-weekly injections of intramuscular penicillin works better.⁶
• The duration of treatment is controversial. Many of the UK trials were done in the 1950s when rheumatic fever was more virulent and frequent than it is today, and many of the modern trials are done in countries where this situation still prevails. Some authorities believe prophylaxis should be lifelong. Others recommend this should only be continued for the first few years after an acute attack in patients under the age of 18, or for those who have sustained severe cardiac damage.⁷

• Rifampicin is recommended first line treatment:
  • 600 mg every 12 hours for 2 days for an adult
  • 10 mg/kg every 12 hours for 2 days for a child over 1 year
  • 5 mg/kg for a child under one year
• Alternatives are:
  • Ciprofloxacin (unlicensed use) 500 mg as a single dose (child 5-12 years 250 mg)
  • I/m ceftriaxone (unlicensed use) 250 mg as a single dose (child under 12 years 125 mg)⁹

Systematic evidence is limited due to the ethics of not giving prophylaxis to a control sample, and there is therefore limited information as to which contacts to treat.¹⁰ Contact tracing is normally undertaken by local public health clinicians, and further guidance has been issued by the Health Protection Agency,¹⁰ as follows:

Prophylaxis indicated

Irrespective of vaccination status, chemoprophylaxis should be offered to the following individuals:

• Those who have had prolonged close contact with the case in a household type setting during the seven days before onset of illness, e.g.
• Those living and/or sleeping in the same accommodation
• Pupils in the same dormitory
• Boy/girlfriends
• University students sharing a kitchen in a hall of residence
• Those who have had transient close contact with a case only if they have been directly exposed to large particle droplets/secretions from the respiratory tract of a case around the time of admission to hospital (e.g. healthcare workers).

Prophylaxis not indicated

(unless already identified as close contact):

• Staff and children attending same nursery or creche
• Students/pupils in same school/class/tutor group
• Work or school colleagues
• Friends
• Residents of nursing/residential homes
• Kissing on cheek or mouth (intimate kissing would normally bring the contact into the close prolonged contact category)
• Food or drink sharing or similar low level of salivary contact
• Attending the same social function
• Travelling in next seat on same plane, train, bus, or car

Rifampicin is recommended by the Department of Health¹¹:

• 600 mg once daily for 4 days (regimen of choice for adults)
• Child 1-3 months 10 mg/kg once daily for 4 days
• Over 3 months 20 mg/kg once daily for 4 days (max. 600 mg daily)
• Should be given to all household contacts, irrespective of immunisation status, except for children under 4 who have been fully immunised
• Should also be offered to all room contacts - teachers and children - if two cases occur in a playgroup, nursery or creche within 120 days¹¹

• The Department of Health recommends erythromycin¹¹:
  • For adults and children over 8 for 7 days 500 mg every 6 hours
  • For children 2-8 years 250 mg every 6 hours
  • Under 2 years 125 mg every 6 hours
  • The Green Book cites penicillin as another option
• Diphtheria is still prevalent in parts of Asia, South America, Africa and India, and may well re-emerge in the UK if immunisation rates are not maintained.¹¹
• As well as antibiotic prophylaxis, partially or unimmunised individuals should complete immunisation according to the UK schedule.
• Completely immunised individuals should receive a single reinforcing dose of a diphtheria-containing vaccine according to their age.¹¹

• UK guidelines recommend erythromycin¹²:
  • Adults and children over 8 years, 250-500 mg every 6 hours for 7 days
  • Children 2-8 years use 250 mg every 6 hours
  • Under 2 years 125 mg every 6 hours
• Evidence for antibiotic prophylaxis weak
• Because of well-known side effects of erythromycin (mainly gastrointestinal), clinicians should take a cautious approach to prescribing
• Prophylaxis should be offered to a household contact if :
  • A newborn baby or young infant
  • Any unimmunised member of their household
  • Contacts 5 years or over if they did not receive pre-school pertussis booster (not given to those born before 1996 in the UK).
  • No benefit in giving prophylaxis more than 21 days from the date of onset of the primary case. Unimmunised or partially immunised contacts should complete their course of vaccine.

• Evidence supports the use of phenoxymethylpenicillin:^13,2
  • 500 mg every 12 hours for adults.
  • Children under 5 years use 125 mg every 12 hours
  • 6-12 years use 250 mg every 12 hours
  • If cover also needed for H. influenzae in a child give amoxicillin instead:
  • Under 5 years 125 mg every 12 hours
  • Over 5 years 250 mg every 12 hours)
• Systematic evidence supports use of antibiotic prophylaxis, irrespective of immunisation status, from the age of four months.¹⁴
• Erythromycin may be used for those allergic to penicillin, but effectiveness less well supported by evidence.¹⁵
• One trial supported the cessation of prophylaxis at the age of five providing child had had at least two years of antibiotic, was fully immunised, and had had no episodes of pneumococcal infection or a splenectomy.
• Parents should be counselled to report any febrile illness¹⁶
• Similar considerations apply to splenectomised patients or patients with hyposplenia, irrespective of immune status
• Evidence for stopping antibiotic prophylaxis less convincing, many experts advise continuing indefinitely

As for dental procedures; post-operative dose may be given parenterally if swallowing is painful.^2,17

As for special risk patients undergoing dental procedures under general anaesthesia except that clindamycin is not given. If the urine infected, prophylaxis should also cover the infective organism.²

As for genito-urinary procedures, but only required for patients with prosthetic valves or those who have had endocarditis only.²

• Patients with prosthetic joint implants (including total hip replacements) do not require antibiotic prophylaxis for dental treatment.
• The evidence to support prophylaxis is lacking and there is no benefit in exposing patients to adverse effects.¹⁸
• Intercurrent infection should be treated as appropriate.
• The frequency of joint infection after dental treatment is extremely small, the risk of streptococcal infection even smaller.²

Antibacterial prophylaxis against endocarditis is not required.¹ However, this applies to surgery on clean skin. Prophylaxis should be considered if procedures on infected areas are carried out (e.g. treatment of wound infections) if the surgery cannot be postponed until the infection is treated.¹⁹

Antibiotic prophylaxis is not required for patients having dental treatment who are immunosuppressed (including transplant patients and patients with indwelling intraperitoneal catheters), providing there is no other indication for prophylaxis. There is little evidence that such patients acquire infection after dental procedures.¹

Benzylpenicillin 300-600 mg should be given every 6 hours for 5 days. For penicillin-allergic patients, give metronidazole 400-500 mg every 8 hours.^15,20

• The Joint Tuberculosis Committee recommends chemoprophylaxis for the following:²¹
  • Patients with documented recent tuberculin conversion
  • Tuberculin-positive children identified in BCG schools programme
  • Children under 2 years in close contact with smear-positive tuberculosis (including those previously vaccinated with BCG but now showing strongly positive tuberculin test)
  • Children under 16 years showing a positive tuberculin test at new immigrant or contact screening.
  • Chemoprophylaxis should also be considered for immigrant adults 16-34 years without a BCG scar but with strongly positive tuberculin test.
• The BNF recommend a regime of isoniazid 300 mg daily for 6 months to adults 5-10 mg/kg daily (max. 300 mg daily) to children.
• An alternative is isoniazid 300 mg daily rifampicin 600 mg daily (450 mg if less than 50 kg) for 3 months for adults and isoniazid 5-10 mg/kg daily (max. 300 mg daily) rifampicin 10 mg/kg daily (max. 600 mg daily) for children.
• There is a risk of hepatotoxicity with isoniazid, but this is far outweighed by the risk of developing TB if prophylaxis is not given.²²

• Operations on stomach or oesophagus for carcinoma - The Scottish Intercollegiate Network Guidelines Network (SIGN) recommend antibiotics unless local guidelines specify exceptions.²³ SIGN advise that the selection of antibiotics should be guided by local policy.
• Additional intra-operative or postoperative doses of antibacterial may be given for prolonged procedures or if there is major blood loss.²
• Open biliary surgery - the BNF recommends giving a single dose of i/v cefuroxime i/v metronidazole or i/v gentamicin i/v metronidazole.²
• Metronidazole may be given by suppositories, two hours before surgery to allow absorption.
• There appears to be no benefit in giving antibiotic prophylaxis prior to elective laparoscopic cholecystectomy.²⁴
• Resections of colon and rectum for carcinoma, and resections in inflammatory bowel disease, and appendicectomy - give a single dose of i/v gentamicin i/v metronidazole.
• An alternative is i/v cefuroxime i/v metronidazole or i/v co-amoxiclav alone.²
• There is considerable evidence to support the role of pre-operative antibiotics in the reduction of post-operative infections.²⁵
• Endoscopic retrograde cholangiopancreatography - a single dose of i/v gentamicin or oral or i/v ciprofloxacin is advised by the BNF.²
• This is a controversial area, and some experts argue that increased infection control measures during the procedure would obviate the need for prophylaxis.²⁶
• Prophylaxis is however, particularly important if there is bile stasis, pancreatic pseudocyst, a history of cholangitis or neutropenia.²

• Transrectal prostate biopsy - SIGN recommend prophylactic antibiotics.²³ The BNF advise a single dose of i/v cefuroxime i/v metronidazole or i/v gentamicin.
• Additional intra-operative or postoperative doses of antibacterial may be given for prolonged procedures or if there is major blood loss.
• Metronidazole may be given in suppository form.² There is an evidence base to support that there is a significant risk of infection without antibiotic cover has a significant risk of infection.²⁷

SIGN advise the use of antibiotics as prophylaxis.²³ The BNF recommend a single dose of oral ciprofloxacin or i/v gentamicin or i/v cefuroxime. There is a discussion in the literature about the benefit of various regimes²⁸ and methods of delivery²⁹ but no meta-analyses from which definitive guidance can be drawn.

• Caesarean section - SIGN support the use of prophylactic antibiotics unless local policies identify exceptions.²³ The BNF advises a single dose of i/v cefuroxime, administered immediately after the umbilical cord is clamped. If there is a history of penicillin or cephalosporin allergy, i/v clindamycin is an alternative.¹⁵ Again, there is a discussion in the literature about various regimes,³⁰ and also about the timing of medication.³¹
• Hysterectomy - SIGN recommend prophylaxis for both abdominal and vaginal procedures, unless local policies identify exceptions.²³ The BNF recommend a single dose(1) of i/v cefuroxime i/v metronidazole(2) or i/v gentamicin i/v metronidazole(2) or i/v co-amoxiclav alone. There is some evidence that a two-dose regime is better, due to increased blood flow, and hence rapid clearance, from the operation site, particularly where the procedure is extensive, e.g. cancer surgery.³²
• Termination of Pregnancy - the standard guidance used to be to give antibiotic prophylaxis in all cases to prevent complications from pre-existing sexually-transmitted infection. However, recent work suggests that such precautions may not necessary providing patients are carefully screened.³³ The BNF recommend a single dose of oral metronidazole, but give doxycycline if genital chlamydial infection cannot be ruled out.² One trial suggests weak protection with metronidazole in patients with bacterial vaginosis, but larger randomised trials are needed.³⁴ One trial using blanket cover for all patients with oral oxytetracycline and metronidazole suppositories reduced the rate of post-operative infection, presumably by treating undiagnosed bacterial vaginosis and chlamydia, and found that the cost-benefit of this approach was significant.³⁵

• Reconstructive arterial surgery of abdomen, pelvis or legs - SIGN recommend antibiotic prophylaxis.²³ The BNF advises a single dose of i/v cefuroxime or i/v gentamicin.
• Additional intra-operative or postoperative doses may be necessary for lengthy procedures or if there is major blood loss.
• For patients at risk of anaerobic infections (e.g. those with diabetes, gas gangrene, undergoing amputation), add i/v metronidazole.
• Substitute i/v vancomycin for cefuroxime or gentamicin if there is a high risk of methicillin-resistant Staphylococcus aureus.²
• There is some evidence that multiple doses regimes give better outcomes generally.³⁶