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 &a 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
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
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 puperacillin/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
What’s the three drug regimen recommended for multibacillary leprosy
Rifampicin
Dapsone
Clofazimine
Two drug regimen for paucibacillary leprosy
Rifampicin
Dapsone
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
Ethambutol
Pyrazinamide
Isoniazid (with pyridoxine)
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