Chemoprophylaxis Flashcards
Define chemoprophylaxis
- Antimicrobial drug to prevent an infection
- Use of anti-malarial drugs to prevent malaria in travellers from the UK visiting malaria endemic countries
When to use chemoprophylaxis
- Significant and predictable risk of infection
- Consequences of infection may be serious
- Period of highest risk can be ascertained
- Microbial causes of infection are predictable
- Antimicrobial sensitivity of the infections are predictable
- Cheap and reasonably safe antimicrobial agents available
Doxycycline and sunlight
Doxycycline may cause your skin to be more sensitive to sunlight than it is normally. Exposure to sunlight, even for short periods of time, may cause skin rash, itching, redness or other discoloration of the skin, or a severe sunburn.
Cons of chemoprophylaxis
- Adverse effects - side effects, drug interactions
- Disturbance of the normal human bacterial flora
- Colonisation with more antibiotic-resistant bacteria
- Selection of antibiotic resistance
- Cost
Innapropriate use: long-tern antibiotics to prevent UTI in in-patients with indwelling urinary catheters
Chemoprophylaxis in Malaria
- No vaccine
- Variet of regiments
- Chloroquine +/- proguanil
- Mefloquine
- Doxycycline, atovaquone (Malarone = proguanil + ataovaquone)
- Continued for 4 weeks after leaving malarious area (except Malarone which is 1 week)
Chemoprophylaxis of Group A strep
Oral penicillin given to close contacts of patients with invasive group A streptococcal infections
- Alternative erythromycin or azithromycin
- Prophylaxis for both mother and baby recommended if either develops invasive group A strep infection in the neonatal period
- Prophylaxis for all household contacts if 2 or more cases of invasive group A strep disease in 30 days
Chemoprophylaxis for group B strep
- Part of the normal vaginal flora
- Can cause neonatal meningitis and septicaemia
- Particular risk for pre-term, low birth weight infants
- Penicillin or clindamycin during laber if at risk:
- Pre-term labour
- Prolonged rupture of membranes
- History of previous group B strep neonatal infection in previous pregnancy
- Mother known to be carrying Group B strep in this pregnancy
Chemoprophylaxis for rheumatic fever
immunological response to infection with Streptococcus pyogenes (Group A Strep [Beta-haemolytic streptococcus Lancefield Group A])
After 1 doccumented attack: Penycillin 250 mg bd un til 16 yo
- Alternatively sulfadiazine
Chemoprophylaxis for Bacterial meningitis and meningococcal disease
Most meningitis is of viral origin
Invasive infection by N. menigitidis
National immunisation
• conjugated vaccine against serogroup C strains (infants)
• MenB–new from Oct 2015(infants)
Chemoprophylaxis of bacterial menigitids and meningococcal disase
Generally only for kissing contacts, mouth-mouth resuscitation, or those living in the same house-hold except in outbreak situations. Healthcare workers generally do not require prophylaxis unless significant contact with respiratory secretions
- Rifampicin - NB interactiosn with pill and contact lenses
- Ciprofloxacin
- Ceftriaxone IM for pregnant conacts
Chemoprophylaxis for Hib bacterial meningitis
Cause of meningitis mainly<4years
For ALL household contacts IF child <4 years old in the house
– Rifampicin 600 mg (adults) po od for 4 days
Chemoprophylaxis in UTI
Frequency of infections can be reduced in some cases by prophylactic antibiotics (trimethoprim, nitrofurantion, cephalexin)
NOT suitable for patients with indwelling urinary catheters
Chemoprophylaxis in splenectomised patients
- An overwhelming post-splenectomy infection (OPSI) or Overwhelming post-splenectomy sepsis (OPSS) is a rare but rapidly fatal infection occurring in individuals following removal of the spleen. The infections are typically characterized by either meningitis or sepsis, and are caused by encapsulated organisms including Streptococcus pneumoniae.*
- Penicillin to prevent pneuococcal infections
Chemoprpylaxis for immunocompromised apteints
- 10 immunodeiciencies, HIV, immunomalignancies, chemotherapy, steroids, transplants.
- HIV: Co-trimoxazole to prevent recurrent PCP following 1st infection or when CD4 count <200
- Neutropenia: ciprofloxacin to prevent Gram-negative bacterial infections
- BMT: As above + aciclovir (HSV) + fluconazole (candida)
Chemoprophylaxis for trauma
antibiotic prophylaxis
• co-amoxiclav, metronidazole
• doxycycline (pen allergic)
