Chapter 5- Infection Flashcards
What are the safest antibiotics in pregnancy?
Penicillins and cephalosporins
If someone has a virus - when are antibacterials indicated?
Only to treat secondary bacterial infections e.g bacterial pneumonia secondary to influenza
Two conditions that require prolonged courses of antibiotics
TB Osteomyelitis
Two drugs used to prevent recurrence of rheumatic fever
Phenoxymethylpenicillin Sulfadiazine
Prevention of pneumococcal infection in asplenia or in patients with sickle cell disease
Phenoxymethylpenicillin (Pen allergy? - erythromycin)
Prevention of early onset neonatal infection
Benzylpenicillin (clindamycin if history of allergy to penicillins)
Four sites of action for antimicrobials
Cell wall Protein synthesis Cell membrane Nucleus acid synthesis
Name 4 classes of b-lactams
Penicillins Cephalosporin Carbapenems Monobactams
Name two glycopeptides
Vancomycin Teicoplanin
True or false: gram positive bacteria have a thicker peptidoglycan layer and NO cell membrane
TRUE
Is gentamicin bactericidal
YAH
Are tetracyclines bactericidal
Nah- bacteristatic
Name four aminoglycosides
Gentamicin Amikacin Tobramycin Streptomycin
How do aminoglycosides work??
Inhibit protein synthesis
Use and indications for the aminoglycosides
IV for serious infections from AEROBIC bacteria e.g septicaemia, complicated UTI, nosocomial RTI
Spectrum of activity for aminoglycosides
Active against many G -be including pseudomonas, and some G+ve e.g staphylococci - (streptomycin can be used for TB, mycoplasma)
Are tetracyclines broad spectrum? And name three
YES doxycycline Minocycline Oxytetracycline
Oral indications for tetracyclines
Acne
RTI
Chlamydia
SSTI
Mycoplasma
Periodontal disease
Can you use tetracyclines in under 12s and pregnancy
NO - tetracyclines deposit in forming bones/teeth
Name three macrolides
Erythromycin Azithromycin Clarithromycin
When are macrolides good?
Alternative to penicillins for treating strept infections
What type of drug is clindamycin and what’s a side effect
Lincosamide Side effect: Cdiff
What type of drug is linezolid
Oxazolidinone - active against G+ve bacteria is a last resort antibiotic for e.g MRSA, vanc resistant enterococci
Tell me about fusidic acid
Narrow spectrum for staph infections – Topical: skin &eye
Oral/IV: osteomyelitis & endocarditis
Name a broad spectrum antipseudomonal penicillin
Piperacillin with tazobactam Ticarcillin with clavulanic acid
Antibiotic for MRSA
Vancomycin or teicoplanin
Antibiotics for meningitis
Benzylpenicillin Cefotaxime Chloramphenicol
First second and third line for C diff
Metronidazole Vancomycin Fidaxomicin
Name two b-lactamase resistant penicillins
Flucloxacillin Co-amoxiclav
Three common bacteria in meningitis
Neisseria meningitidis Strep pneumoniae Haemophilus influenza
Glycopeptides vancomycin and teicoplanin are active against what?
Gram +ve
Name three aminoglycosides that are active against pseudomonas
Gentamicin Amikacin Tobramycin
Contraindications to aminoglycosides
Myasthenia gravis (aminoglycosides may impair neuromuscular transmission)
Parenteral aminoglycosides should ideally not exceed what duration?
7 dayz
Peak level of amikacin
30mg/litre
Trough level of amikacin multiple dose regimen
<10mg/litre
Trough level of once daily amikacin
<5mg/litre
Peak gentamicin
5-10mg/litre
Trough gentamicin
<2mg/litre
Neomycin is safe for systemic use- true or false?
FALSE- too toxic for systemic use
The aminoglycosides streptomycin is used for what?
TB
Safety information with streptomycin
Side effects increase after cumulative dose of 100g which should only be exceeded in exceptional circumstances
Peak tobramycin
10mg/litre
Trough tobramycin
<2mg/litre
What can tobramycin dry powder inhalation be used for?
Pseudomonas lung infection in cystic fibrosis
Name two carbapenems active against pseudomonas aeruginosa
Imipenem and meropenem
What is cilastatin
Specific enzyme inhibitor given with imipenem to prevent its renal metabolism
Which carbapenem has less seizure inducing potential?
Meropenem
Name two cephalosporins used for infections of the CNS (meningitis as an example)
Cefotaxime Ceftriaxone
What percentage of people whom are allergic to penicillin will be allergic to cephalosporins
0.5-6.5%
If cephalosporins essential in a penicillin allergic patient as there’s no alternative which ones should be avoided
Cefaclor Cefadroxil Cefalexin Cefradine Ceftaroline
Radars and Arrows.
Name the cephalosporin that has good activity against H.influenzae
Cefaclor
Name the cephalosporin that needs to be given with food to increase absorption
Cefuroxime
Caution with ceftriaxone
History of hypercalciuria
history of kidney stones
What is tazobactam
Beta lactamase inhibitor
Spectrum of activity for the glycopeptides teicoplanin and vancomycin and telavancin
Active against aerobic and anaerobic gram positive bacteria including MRSA
Which has a longer half life teicoplanin or vancomycin
Teicoplanin
The lincosamide clindamycin is active against what
Gram positive cocci including streptococci and penicillin resistant staphylococci and many anaerobes especially bacteria fragilis
Which has more activity against Haemophilus influenzae erythromycin or azithromycin
Azithromycin! Erythromycin has poor activity against it
Cautions with macrolides?
Electrolyte disturbance (predisposition to QT prolongation) May aggravate M gravis
Caution for erythromycin
Avoid in acute porhyrias (its a genetic blood disorder) Features are tachycardia and unlocalised pain.
Name a monobactam and what’s it’s spectrum of activity
Aztreonam: gram -ve only including p.aeruginosa, neisseria meningitidis, h.influenzae
Activity of metronidazole
Anaerobic bacteria and Protozoa
Which has a longer duration of action - metronidazole or tinidazole?
Tinidazole
Are penicillins bactericidal or bacteristatic
Bactericidal
What is the penicillin pivmecillinam hydrolysed to
Mecillinam
Caution with Piperacillin/tazobactam and ticarcillin/clavulanic acid
High doses may lead to hypernatraemia owing to sodium content of preparations
Caution with preparations containing clavulanic acid
Cholestatic jaundice
What is in co-fluampicil
Ampicillin + flucloxacillin
Important safety information with flucloxacillin
Cholestatic jaundice and hepatitis
Penicillins can cause cholestatic jaundice - its more common in what age and gender?
Male over 65
Is temocillin penicillinase resistant?
Yes
Contra indications to colistin
Myasthenia gravis
Can colistin be used for pseudomonal lung infection in cystic fibrosis
Yes
Moxifloxacin has been associated with what adverse effects
QT interval prolongation and life threatening hepatotoxicity
CSM safety information with quinolones
Convulsions may be induced - taking NSAIDs at the same time may induce them Tendon damage Can prolong QT
Common/very common side effect of ciprofloxacin
Flatulence
Side effect of tetracyclines related to the brain
Benign intracranial hypertension- headache and visual disturbances discontinue treatment!
Directions for administration of doxycycline
Plenty of fluid while sitting or standing and taken during meals
Monitoring requirements for minocycline
If treatment continued for longer than 6 months, monitor every 3 months for hepatotoxicity l, pigmentation and for systemic lupus erythromatosus
Max duration for topical fusidic acid
10 days to avoid resistance developing
Spectrum of action for linezolid
Gram positive including MRSA
Important safety information with linezolid
Severe optic neuropathy if used longer than 28 days Blood disorders
Trimethoprim is a folate antagonist therefore shouldn’t be given when
Preganancy - teratogenic risk in first trimester
What should patients be told to look out for if on long term treatment with trimethoprim
Blood disorders (fever, sore throat, rash, mouth ulcers, purpura, bruising, bleeding
Treatment duration of anthrax
60days with Ciprofloxacin if under 12. Doxycycline if over 12…
What’s the three drug regimen recommended for multibacillary leprosy
Dapsone Rifampicin Clofazimine
DR.C
Two drug regimen for paucibacillary leprosy
Dapsone Rifampicin
DR
Name two antimycobacterials
Clofazimine Dapsone
Antibiotics used in Lyme disease
Doxycycline Amoxicillin Cefuroxime Macrolides
How many drug and treatment phases in TB treatment
Initial phase- 4 drugs Continuation phase- 2 drugs
Name the four drugs in the initial phase of TB treatment
Rifampicin Isoniazid Pyrazinamide Ethambutol (with pyridoxine to prevent peripheral neuropathy caused by isoniazid)
How long is the initial phase of TB treatment
2months
When do you use streptomycin in TB
During initial phase if resistance to isoniazid is established prior to treatment
Drugs in continuation phase of TB and for how long
Rifampicin Isoniazid (+pyridoxine) 4months
In TB - supervised consumption is how often a week?
Three times a week
True or false: streptomycin can be used in pregnancy
False
How long is the continuation phase for extrapulmonary CNS TB
10months
Treat patients for latent TB if close relative has TB if they are under what age
65
When can ethambutol be omitted from says treatment
If resistance from isoniazid is not suspected
Why is pyridoxine given with isoniazid
To prevent peripheral neuropathy
What’s a key side effect of ethambutol and when is it most likely to occur
Ocular toxicity - impaired renal function
Contraindication to pyrazinamide
Acute attack of gout
Bacteria that’s most common cause of UTI
Escherichia coli
Other bacteria causing UTIs
Staph saprophyticus Proteus Klebsiella Pseudomonas aeruginosa Staph epidermidis Enterococcus faecalis
Name the fungal infection that commonly affects the respiratory tract
Aspergillosis
Name the most common cause of fungal meningitis
Cryptococcal meningitis
Why is itraconazole and terbinafine used more than griseofulvin
Broader spectrum and used for shorted duration
Which is active against aspergillus: itraconazole or fluconazole
Itraconazole
Which is more reliably absorbed: itraconazole or fluconazole
Fluconazole
For optimal absorption itraconazole requires what
Acid environment
Which triazole antifungal should be avoided or used with caution in liver disease
Itraconazole
What formulations of amphotericin are available and why
Lipid formulations e.g ambisome - makes then Mmm significantly less toxic
What’s used with amphotericin for its synergistic effect
Flucytosine
True or false: amphotericin should be prescribed by brand
True
Fluconazole can be sold to public for vaginal candidiasis if what?
Aged 16-60 and not more than 150mg
Important safety information with itraconazole
Following reports of heart failure caution is advised when prescribing itraconazole for those at high risk of heart failure
Itraconazole should be avoided when?
Patients with ventricular dysfunction or a history of heart failure unless the infection is serious
Common cause of pneumonia in aids
Pneumocystis jirovecii
Treatment options for pneumocystis pneumonia mild to moderate disease
Co-trimoxazole Atovaquone Dapsone + trimethoprim Clindamycin + primaquine
Treatment options for severe pneumocystis pneumonia
Co-trimoxazole Pentamidine Corticosteroid
Treatment of choice for threadworms in those over 6 months
Mebendazole as a STAT dose - can give 2nd dose 2 weeks after
Mebendazole licensing?
Can be sold OTC for those over 2 years if package is clearly labelled 100mg as single dose and not more than 800mg is in a container
Side effects of mebendazole
Abdominal pain Diarrhoea Flatulence Stevens J syndrome (rare)
Treatment of acute non complicated falciparum malaria
Artemether with lumefantime
What is primaquine used for in malaria
Used to eliminate the liver stages of P. Vivax or P. Ovale following chloroquine treatment
Name the two most important herpes virus pathogens
Herpes simplex virus Varicella zoster virus
True or false- valaciclovir is a prodrug of aciclovir
True
Name a HIV fusion inhibitor
Enfuvirtide
Name three HIV integrase inhibitors
Dolutegravir Elvitegravir Raltegravir
Name 4 non-nucleoside reverse transcriptase inhibitors
Efavirenz Etravirine Nevirapine Rilpivirine
Name two drug used in influenza
Oseltamivir Zanamivir
Oseltamivir should be given within how many hours of symptoms onset
48 hrs
Zanamivir should be given within how many hours of symptoms onset
36hrs
First line options for aspergillosis fungal infection
Voriconazole Liposomal amphotericin
Second line options for aspergillosis
Caspofungin Itraconazole Posaconazole
What’s the fungus that most commonly causes fungal meningitis
Cryptococcosis
Signs of an infection and Clinical Markers?
Identify the varying needs of Children, Elderly and Penicillin allergic patients, stating the drugs to avoid and where applicable what can be used instead
Highlight the Antibiotic drugs to avoid or be aware of in Hepatic/ Renal and Pregnancy
Whats the side effect issue with broad spectrum Abx
They can precipitate diarrhoea and they kill off Good bacteria flora.
As a General Rule of Thumb, how do we treat:
Staphlococci:
MRSA:
Streptococci:
Anaerobic Bacteria
Pseudomonas Aeruginosa
Treatment of Meningococcal Meningitis?
Ciprofloxacin or Rifampixin or IM Ceftriaxone
Treatment of Haemophilus Influenzae
Rifampicin or Ceftriaxone.
What is this and what is it’s treatment?
Diptheria, Treat with Erythromycin or another macrolide
What is this most likely to be and what is the treatment?
Dog Bite. Treat animal bites with Co-Amoxiclav alone or Doxycycline + Metronidazole if penicillin allergic.
consider rabies prophylaxis
What ABx do we give when inserting a pacemaker, and when in terms of timing?
Single dose of IV Cefuroxime alone or Flucloxacillin + Gentamicin 30 minutes before the procedure.
What is this and generally what is the causative organism? and how do we treat
Endocarditis: Staph Aureus or Meticillin-Resistant Staph Aureus
Penicillin or Vancomycin if penicillin allergic… Low Dose Gentamicin features here also
Name the causative oganisms of this condition and tx
Meningococci (give Benzylpenicillin or cefotaxime)
Pneumococci (ceftriaxone)
Haemophilus Influenzae (cefotaxime or ceftriaxone)
Listeria (amoxicillin or ampicillin)
Treatment for CAP Low-severity
Amoxicillin or Ampicillin for 7 days (can be up to 14-21 if caused by staphlococci)
Alternatives: Doxycycline or Clarithromycin…
Difference between otitis externa and otitis media? and treatment?
Otitis media is an infection of the middle ear that causes inflammation (redness and swelling) and a build-up of fluid behind the eardrum. Initial treatment is with Amoxicillin. or Co-Amoxiclav.
Otitis externa is a condition that causes inflammation (redness and swelling) of the external ear canal, which is the tube between the outer ear and eardrum.
Initial treatment is with flucloxacillin or Clarithromycin
The difference is location.
What are the symptoms of Bacterial Vaginosis? What is the treatment? and whats the appearance between BV and Thrush
Oral Metronidazole OR Metronidazole topical gel 5 days/ Clindamycin topical gel
Thrush also has a thick white discharge like cottage cheese
Causative bacterial organisms for pneumonia in community and hospital?
Staphlycoccus Aureaus, and Pseudomonas Aeruginosa and Legionella
CAP treatment in modeate severity?
Amoxicillin (or Ampicillin) + Clarithromycin/Erythro/Azithro or doxycycline alone
If MSRA is suspected then give Vanco or Teicoplanin.
Treatment of High severity CAP?
Benzylpenicillin + Clarithromycin or Azithromycin/ Erythromycin
If MRSA suspected: Vancomycin.
Treatment is typically 7-10 days, but can be up to 14-21 days if severe.
If life threatening or in nursing home, Co-Amoxiclav + Clarithromycin. alternative: Cefuroxime + Clalrithro.
When Pneumonia is caused by Atypical Pathongens such as legionella, how do we treat CAP?
Give Clarithromycin and add Rifampicin for the first few days if its a high severity rifampicin for the first few days. Alternatives to Rifampicin is Quinolone.
How to treat HAP?
Early onset (less than 5 days) after administration to hospital – Co-Amoxiclav or Cefuroxime 7 days
Late onset infection (more than more than 5 days on admission) Piptaz or broad spectrum cephalosoprin or a quinolone e.g Ciprofloxacin.
If MRSA suspected: Vancomycin
If severe caused by an P.Aeruginosa consider adding IV Aminoglycoside.
What is this a typical example of, and what are signs and symptoms?
Impetigo. it looks like:
- look a bit like cornflakes stuck to your skin
- get bigger
- spread to other parts of your body
- be itchy
- sometimes be painful
If it is local
- Topical Fusidic Acid
- Mupirocin (if MRSA)
If it is all over the body:
- Oral Flucloxicillin
- Phenoxymethylpenicillin (if severe infection detected)
- Clarithromycin if penicllin allergic.
what is this and whats the underlying signs? for treatment? what’s
Erysipelas
You may feel unwell and feverish with a high temperature and shivers. This may start a few hours or a day before the skin changes become visible. The affected skin will become sore, swollen, firm, warm, and red, and blisters may form. The nearest lymph glands may become swollen and tender. The area of affected skin may gradually get larger. These features can develop quite quickly, over hours to a few days.
Usually the face and the legs.
Treatment:
- Phenoxymethylpenicillin
- Benzylpenicillin
- High dose Flucloxicillin if severe.. or Clarithro in allergy.
What is this condition and how do we treat it?
Cellulitis – can be caused by insect bites/ cuts/ surgical incisions…
Treatment:
Flucloxacillin high dose.
Streptococcal infection confirmed replace phenoxymethylpenicillin or benzyl with fluclox.
If gram-negative bacteria or anaerobes susppected, use broad-spectrum abx. if penicillin allergic , clindamycin or clarithromycin.
what is this condition, what causes it and how to treat it? how can it be prevented
Mastitis occurs in breastfeeding women
Milk stasis can occur for a number of reasons, including:
- a baby not properly attaching to the breast during feeding
- a baby having problems sucking
- infrequent feeds or missing feeds
- In some cases, this build-up of milk can also become infected with bacteria. This is known as infective mastitis
Treatment:
- Flucloxicillin 10-14 days.
- Erythromycin in allergy 10-14 days.
Steps to prevent mastisis?
- let baby finish feeds before removing
- encourage baby to drink more, esp when breasts feel full
- avoid pressure on breasts.
How do we treat animal bites
cleans wound thoroughly – for tetanus-prone wound, give human tetanus immmunoglobin + vaccine if necessary.
consider rabies prophylaxis
Assess risk of blood-bourne viruses (and HIV + Hep B + C)
Give prophylaxis to prevent viral spread.
Co-Amoxiclav treatment. Doxy + Metro if allergy.
What drug Abx does entamycin have poor activity against?
Haemolytic streptococci and pneumococci.
When used for the blind therapy of undiagosed serious infections, what is gentamycin accompanied with?
Gentamycin is accompanied with metronidazole and penicillin
in gentamycin-resistant enterococcal endocarditis, what can we give?
streptomycin in this case
What is the standard duration of treatment for gentamycin?
7 days long ideally for gentamycin
A once daily high dosage regimen of an aminoglycoside should be avoided in adults with createnine clearance below..
Less than 20ml/minute
A once daily high dosage regimen of an aminoglycoside should be avoided in children with createnine clearance below..
20ml/minute
What trimester bears the greatest risk to mothers on aminoglycoside and what is the nature of the teratogenicity?
second and third trimester – greatest risk to pregnant women. There’s a risk of auditory or vestibular damage
What is the most key thing to monitor for patients on aminoglycosides?
Renal functioning. If there is impairment in renal functioning, the dose must be increased.
In patients with normal renal functioning, how often do we measure aminoglycoside serum conc? Does this apply to children too
measured after 3 or 4 doses and after a dose change.
Also applies to childen with normal renal functioning. Includng auditory and vestibular
whats this and how does it differ from a similar cough
Croup
Symptoms: cough in baby – worse at night. Pertussis is coughing that is whooping followed by vomiting.
whats this?
measles red blotchy rash across body – inflamed eyes / fever / dry cough and runny nose
what is this
mumps
whats this
rubella: symptoms are red or pink rash that begins on face and spreads downwards to neck and body. Muscle pain also and mild fever
what is this?
scarlett fever: Symptoms are pink, red rash often preceded by sore throat on headache and whiteness on tongue. Rash feels like sand paper.
whats this
chicken box – blistering/ itchy and can be fever…
