Chapter 5: Infection Flashcards
Signs and symptoms of infection?
- fever or malaise, aches and pains
- pus, swelling or inflammation
- drowsiness in children
- confusion in the elderly
- worsening renal function
Clinical markers for infection?
- low blood pressure
- raised blood glucose
- high ESR, C-reactive protein, temperature, respiratory rate, pulse
What is antimicrobial stewardship and its principles?
“An organisation or healthcare system wide approach to promoting and monitoring the judicious use of antimicrobials to preserve future effectiveness”
- do not treat viral infections with antibiotics
- avoid blind prescribing
- narrow-spectrum antibiotics are preferred except for serious infections where broad spectrum is needed
- avoid prolonged therapy and complete courses
- follow national and local guidelines
- dose varies according to patient factors
- prescribed for oral infections on basis of defined need
What does the choice of antibiotic depend on?
- patient
2. causative agent
When prescribing for children what are some things to know?
- tetracyclines contraindicated in <12 yrs
- quinolones cause arthropathy (joint disease); avoid
When prescribing for the elderly what are some things to know?
- increased risk of c.diff infection; clindamycin has highest risk
- renal/liver impairment and drug interactions
Prescribing in patients who have allergies?
- penicillin-allergic = cross sensitivity with cephalosporins and other B-lactam antibiotics
- alternatives in penicillin-allergic patients
- macrolides
- metronidazole in dental infection
Prescribing in renal impairment ?
- nephrotoxicity: aminoglycoside, glycopeptide
AVOID: - tetracyclines (except minocycline/doxycycline)
- nitrofurantoin (eGFR<45)
Prescribing in hepatic impairment ?
- hepatotoxicity = rifampicin, tetracyclines
- reduce metronidazole dose if severely impaired
- cholestatic jaundice:
- co-amoxiclav
- flucloxacillin
Prescribing in pregnancy?
- c/i = tetracyclines, trimethoprim
- nitrofurantoin causes nausea; avoid at term
- AVOID: MCAT (metronidazole, chloramphenicol, aminoglycosides, tetracyclines), Quinolones and Sulphonamides
- safest antibiotics = penicillin/cephalosporin
Antibiotic cautionary and advisory label?
“space the doses evenly throughout the day and keep taking this medicine until the course is finished, unless you are told to stop.”
GI side effects of antibiotics ?
- nausea, vomiting, diarrhoea and abdominal pain
What is superinfection?
Clindamycin and broad-spectrum antibiotics kill normal flora and allow selective organisms to thrive; causing antibiotic-associated coitis (c.difficile) and thrush (candida) e.g. vaginal thrush
How many people experience allergic reactions?
Around 1 in 15 people experience hypersensitivity reactions to antibiotics, especially penicillins and cephalosporins
What antibiotic is generally used for staphylococci?
Flucloxacillin
What antibiotic is generally used for MRSA?
Vancomycin
What is generally used to treat Streptococci?
Benzylpenicillin or Phenoxymethylpenicillin
What is generally used to treat anaerobic bacteria ?
Metronidazole
What is generally used to treat pseudomonas aeruginosa?
Gentamycin
Clindamycin MOA and spectrum?
Inhibits protein synthesis
Narrow spectrum + bacteriostatic ( a biological or chemical agent that stops bacteria from reproducing)
Clindamycin side effects?
- antibiotic associated colitis
- most frequently with clindamycin - can be fatal
- most common in middle-aged, elderly women, especially after operations
- counselling: if diarrhoea develops; STOP and see GP
Linezolid MOA and spectrum?
Inhibits protein synthesis. Only active against gram-positive bacteria e.g. MRSA and anaerobes
(narrow-spectrum + bacteriostatic)
Alternative to vancomycin in MRSA infection
Linezolid side effects?
- blood disorders
- optic neuropathy if >28 days use
- patient counselling: report visual symptoms; blurred vision, visual field defects and changes in visual acuity and colour vision
Linezolid intercations?
- hypertensive: SSRIs, TCAs, MAOIs (wait 2 weeks after stopping), sympathomimetics, dopaminergics, opioids, 5-HT1 agonists, buspirone, and pethidine (raises blood pressure)
- linezolid is a reversible MAOI
- avoid consuming large amount of tyramine-rich food
Trimethoprim MOA and spectrum?
Inhibits DNA synthesis
Narrow spectrum + bactericidal (kills bacteria)
Trimethoprim use and dose?
UTIs 200mg BD
Trimethoprim side effects?
- anti-folate: teratogenic in first trimester
- blood dycrasias; with long term use
- counselling: report fever, sore throat, rash, mouth ulcers, purpura, bruising, bleeding
- hyperkalaemia
What is co-trimoxaxole?
(trimethoprim/sulfamethoxazole)
- use: prophylaxis and treatment of pneumocytis jrovecii pneumonia.
- side effects; rashes; SJS toxic epidermal necrolysis, photosensivity
Chloramphenicol MOA and spectrum?
Inhibits protein synthesis
Broad spectrum + bacteriostatic
Chloramphenicol use and side effects?
Use: reserved for life threatening infections (also topical use in superficial eye infections)
Side effects
- blood dyscasias
- grey baby syndrome: avoid in pregnant women
Metronidazole MOA and spectrum?
Inhibits DNA synthesis. High activity against anaerobic bacteria and protozoa.
Narrow spectrum + bactericidal
Metronidazole use?
- anaerobic infections e.g. dental infections, antibiotic-associated colitis, h.pylori, rosacea, bacterial vaginosis
- protozoal infections e.g. vaginal trichomoniasis, giadiasis
Metronidazole common side effects and counselling?
Side effects
- GI disturbances
- taste disturbance
- oral mucositis
- furred tongue
Counselling:
- take with or after food
- avoid alcohol; causes disulfram-like reaction
Nitrofurantoin MOA and spectrum?
Damages bacterial DNA
Only active urinary pathogens
(Narrow spectrum + bactericidal)
Nitrofurantoil use and side effects?
Sole use: UTIs
Side effects: nausea, risk of peipheral neuropathy in renal impairment
Nitrofurantoin and pregnancy?
Avoid at term (neonatal haemolysis)
Nitrofurantoin c/i and counselling?
c/i in infants less than 3 months
Counselling:
- take with or after food
- colours urine yellow or brown
Aminoglycosides MOA and spectrum?
Bind irreversibly to bacterial ribosomes. Active against gram-negative aerobe; pseudomonas aeruginosa
Broad spectrum + bactericidal
Aminoglycoside use and administration?
Use: severe sepsis, pyelonephritis and complicated UTI and endocarditis
Given via parenteral injection; not absorbed by gut
- gentamicin
- tobramycin
- streptomycin
- neomycin
- amikacin
Tobramycin?
Aminoglycoside
via inhaler for pseudomonal infection in cystic fibrosis
Streptomycin?
Aminoglycoside
active against mycobacteria reserved for TB
Neomycin?
Aminoglycoside
parenterally toxic. Use in bowel sterilization
Amikacin ?
Aminoglycoside
gentamicin-resistant gram negative baciili
Gentamicin use?
Active against psuedomonas aeruginosa.
Blind therapy in serious infection: with metronidazole/penicillin
What needs to be monitored with gentamicin?
Plasma concentrations –> NARROW THERAPEUTIC INDEX
- must monitor serum levels in parenteral aminoglycosides
- must be determined in:
- elderlu
- obesity
- cystic fibrosis
- high doses
- renal impairment
Gentamicin once daily regimen?
- avoid in renal impairment <20ml/min, HACEK or gram positive endocarditis, burns covering >20% of body
- consult local guidelines for serum monitoring
Gentamicin multiple dose regimens?
- monitor after 3 or 4 doses and after a dose change but in renal impairment requires more frequent and earlier monitoring
What to do in gentamicin therapy if the post dose peak level after 1 hour is too high?
Reduce dose 5-10mg/ml (3-5mg/ml for endocarditis)
What to do in gentamicin therapy if the pre dose trough level before the next dose is too high?
Increase interval <2mg/ml (<1mg/ml for endocarditis)
What to do in renal impairment when prescribed gentamicin?
Increase dosing interval
*in severe renal impairment (<30ml/min) = reduce DOSE
Gentamicin and pregnancy?
- can give gentamicin but avoid unless essential
- must monitor serum concentrations
Gentamicin side effects?
- dose-related; do not exceed 7 days
- commonly occur in elderly and in renal failure; renally cleared
- irreversible ototoxicity: monitor auditory and vestibular function before treatment (counselling: report tinnitis, hearing loss or vertigoO
- nephrotoxicity:
- aminoglycosides excreted by kidnet
- assess renal function before treatment and correct any dehydration
- signs: low urine output/creatinine clearance, high serum creatinine/urea
Other
- peripheral neruoapthy
- impaired neuromuscular transmission (c/i in mysathenia gravis)
- electrolytes HYPO K, Ca and Mg
Gentamicin interactions?
- increased risk of nephrotoxicity: ciclosporin, tacolimus, vancomycin (avoid concomitant nephrotoxic drugs)
- increased risk of ototoxicity: loop diuretics, cisplatin (avoid concomitiant ototoxic drug)
*concomitant ototoxic loop diuretics: separate by long period as possible
Glycopeptides MOA and spectrum?
Inhibits cell wall synthesis
Only active against gram-positive bacteria including MRSA
Narrow spectrum and bactericidal
Glycopeptides?
- vancomycin (active against MRSA)
- teicoplanin
- televancin (only in HAP when other antibiotics are unsuitable)
*vancomycin and teicoplanin must not be given by mouth for systemic infections
Vancomycin use?
Uses; antibiotic-associated colitis, MRSA infections
Given parenterally for serious infections
What needs to be monitored with vancomycin?
Plasma concentrations (NARROW THERAPEUTIC INDEX)
- must monitor serum concs for all patients
- monitor after 3 or 4 doses and after a dose change
- renal impairment requires earlier and regular monitoring = reduce dose
Vancomycin pre dose trough level?
10-15mg/ml
(15-20mg/ml for endocarditis, less sensitive MRSA strains OR complicated S. aureus infections) - vancomycin
Vancomycin and pregnancy?
- avoid vancomycin unless essential
- must monitor serum concentrations
Vancomycin side effects? (parenteral)
- nephrotoxicity: measure renal function, glycopeptides are renally excreted. low urine output/CrCl, high serum creatinine/urea
- ototoxicity: measure auditory function in elderly - look for signs of hearing damage etc. discontinue in signs of tinnitus
- red man syndrome: flushing of upper body caused by rapid infusion and can be associated with hypotension and bronchospasms
- blood dyscasias: monitor FBC. (neutropenia and rarely thrombocytopenia, agranulocytosis
- skin disorders: SJS, itching, rashes, toxic epidermal necrolysis
- thrombophlebitis
Vancomycin interactions?
- ciclosporin (avoid concomitant nephrotoxic drugs etc)
- loop diuretics (avoid concomitant ototoxic drugs)
Tetracyclines MOA and spectrum ?
Inhibits bacterial protein synthesis; binds to ribosomal 30S subunit
Broad spectrum + bacteriostatic
Tetracyclines use?
Uses: lower RTIs, acne, rosacea, malaria, chlamydia
Tetracyclines?
- demeclocycline
- doxycycline (used in malaria and chlamydia: OD)
- lymecycline
- minocycline (broader spec but rarely used)
- oxytetracycline
- tetracycline
- tigecycline (antibiotic structurally related to tetracyclines)
Tetracycline side effects?
- benign intracranial hypertension
- counselling: stop if headache and visual disturbances.
- minocycline (rarely used): causes vertigo, dizziness, irreversible pigmentation, has greatest risk of lupus-erythematosus-like syndrome
Tetracycline c/i’s?
- children under 12
- pregnancy and breastfeeding: deposit in growing bone and teetch and causes teeth discoloration and dental (enamel) hypoplasia
Tetracyclines in renal impairment?
Avoid except doxycycline and minocycline
Tetracycline in hepatic impairment ?
Avoid or use with caution, especially with concomitant hepatotoxic drugs (tetracyclines are hepatotoxic)
Tetracycline counselling points:
PHOTOSENSITIVITY (DD)
- avoid exposure to sunlight
- spf
(doxycycline and demeclocycline)
DECREASED ABSORPTION (DOT): avoid milk! - do not take antacid, Al, Ca, iron, Mg, Zinc salts 2 hours before/after taking (demeclocycline, oxytetracycline and tetracycline)
OESOPHAGEAL IRRITATION (DMT) - swallow whole with plenty of fluid during meals sitting or standing (doxycycline caps, minocycline caps/tabs. tetracycline tabs)
Quinolones MOA and spectrum ?
Inhibits DNA synthesis
Broad spectrum + bactericidal
Quinolones uses?
Uses: lower RTIs. UTIs,
Avoid in MRSA infections (innate resistance)
Quinolones?
- ciprofloxacin
- levofloxacin
- moxifloxacin (QT prolongation, life threatening hepatotoxicity)
- nalidixic acid (1st gen; uncomplicated UTI. Avoid in eGFR<20)
- norfloxacin
- ofloxacin
Quinolones side effects?-
- seizures (lower seizure threshold): with or without previous history
- tendon damage: stop if tendonitis is suspected
- QT prolongation: leads to ventricular arrhythmias (especially moxifloxacin: c/i in risk factors for QT prolongation)
- arthropathy: avoid in pregnancy, children, adolescent
Discontinue if psychiatric, neurological and hypersensitvity reactions occur
Quinolones interactions?
- increased risk of QT prolongation; ventricular arrythmia: SSRI, quinine, amiodarone, macrolide, antipsychotics
- increased risk of seizures: ciprofloxacin and theophylline: pk and pd interaction: ciprofloxacin is an enzyme inhibitor and causes theophylline toxicity: theophylline side effect is convulsions
- NSAIDs induce convulsions
Quinolones counselling points ?
DRIVING: quinolones can impair the performance of skilled tasks; its effect is enhanced by alcohol
ANTACID AND ZINC/IRON: leave 2 hours before or after taking a quinolone. Also avoid milk with ciprofolxacin and norfloxacin
PROTECT SKIN FROM SUNLIGHT, AVOID SUNBEDS
Oflaxacin
Macrolides MOA?
(Penicillin alternative)
Inhibits bacterial protein synthesis by binding to the 50S subunit of the ribosome
Broad spectrum + bacteriostatic
Macrolide use?
- h. pylori
- RTIs
- skin and soft tissue infections
Macrolides?
- azithromycin OD
- clarithromycin BD
- erythromycin QDS/BD
- telithromycin
- spiramycin
Azithromycin dosage regime and how to take?
OD
- before food/indigestion remedies: 2 hour gap
Clarithromycin dosage regime and side effect?
BD
- can cause taste disturbance
Erythromycin dosage regimen and how to take?
QDS/BD
- before indigestion remedies: 2 hour gap
Telithromycin indication and side effects?
For B-lactam resistant infections
Causes visual disturbancs, hepatotoxicty and transient loss of consciousness - driving!
Spriamycin use?
toxoplasmosis (disease that results from infection with the Toxoplasma gondii parasite, one of the world’s most common parasites. Infection usually occurs by eating undercooked contaminated meat, exposure from infected cat feces, or mother-to-child transmission during pregnancy.)
Macrolides side effects?
- GI side effects: nausea, vomiting, abdominal discomfort and diarrhoea and diarrhoea (most with erythromycin)
- QT interval prolongation risk factors: bradycardia, heart disease, hypoK, hypoMg, concomitant QT prolongation drugs
- Hepatoxicity
- Ototoxicity at high doses
How to take macrolides?
Take with or after food
Macrolides interactions?
Erythromycin and clarithromycin are potent enzyme inhibitors
- warfarin = increased risk of bleeding
- statins = increased risk of myopathy
Penicillin MOA and spectrum?
Intefere with bacterial cell wall synthesis.
Not useful in CNS infections except meningitis
Broad spectrum + bactericidal
BETA LACTAM ANTIBIOTICS
Narrow spectrum penicillins (beta-lactamase sensitive)
- benzylpenicillin “pen G”
- phenoxymethylpenicillin “pen V”
Broad spectrim penicillins (inactivated by beta-lactamases)
- ampicillin
- amoxicillin
Penicillinase-resistant penicillins?
Flucloxacillin
Antipsuedomonal penicillins (extended spectrum)
- piperacillin (with tazobactam)
- ticaricillin (with clavulanic acid)
Penicillins side effects?
- Penicillin allergy: rashes or anaphylaxis. Atopic allergies: higher risk of anaphylactic reactions
- True allergy = immediate rash, anaphylaxis, hives. Do not use any beta-lactam antibiotic: cephalosporins, carbapenems, monobactams
- May not be allergic: minor rash; small, not itchy and non-confluent or rash after 72hr, do not withold penicilin for serious infections
Why should you not give penicillin antibiotic as intrathecal injection (the fluid-filled space between the thin layers of tissue that cover the brain and spinal cord)?
ENCEPHALOPATHY - cerebral irritation and can be fatal
When should you not give Broad spectrum penicillins ?
(ampicillin and amoxicillin)
- do not give blindly for sore throats: causes maculopapular rash in glandular fever
What can broad spectrum antibiotics cause ?
Antibiotic-associated colitis
Ampicillin uses and how to take?
- HIGH RESISTANCE; consider before blindly prescribing
- Uses: UTIs, Otitis media, acute COPD exacerbations
- Take before food
BROAD
Amoxicillin use and side effects?
- commonly rxed with clavulanic acid (Co-amoxiclav)
- active against beta-lactamse producing strains
- side effects: cholestatic jaundice: do not exceed 14 days
BROAD
Benzylpenicillin “pen G” uses?
NARROW
- Use: meningitis (meningococcal infections)
- parenteral use only = not gastric acid stable
Phenoxymethylpenicillin “pen V” uses
- uses: RTIs in children e.g. streptococcal throat, tonsilitis
- oral use = gastric acid stable
Pencillinase-resistant: Flucloxacillin uses?
Uses: penicillin-resistant staphylococcal infections except MRSA e.g. skin infections, impetigo, cellulitis
Take BEFORE food
Flucloxacillin side effects?
- cholestatic jaundice and hepatitis
- up to 2 months after treatment
- increasing age and >14 days treatment increases risk
Antipseudomonal penicillin uses?
(piperacillin with tazobactam and ticaricillin with clavulanic acid)
Use: serious infections e.g. septicaemia, complicated UTI, hospital-acquired pneumonia.
Effective against psuedomonas aeruginosa
Temocillin use?
Reserved for beta-lactamase producing strains of gram negative bacteria
Cephalosporins MOA and spectrum?
Inteferes with bacterial cell wall synthesis.
They have similar spectrum of activity to penicillins
(broad spectrum and bactericidal)
Cephalosporins uses?
Orally active
Uses: UTI (pregnancy or second line), sinusitis, otitis media
1st generation cephalosporins? (CEFA)
- cefalexin
- cefadroxil (BD)
- cefradine
2nd generation cephalosporins? (2 foxes for tea)
- cefuroxamine
- cefaclor (protected skin reactions, especially in children)
Parenteral cephalosporins 3rd generation? (“contains t except cefixime”)
- cefixime (orally active)
- ceftriaxone (OD, treats meningitis)
- cefotaxime (treats meningitis)
- ceftazidime
Parenteral cephalosporins 5th gen? (extended spectrum)
- ceftaroline use in CAP and complicated skin and soft tissue infections
Cephalosporin side effects?
- hypersensitivity: do not give in history of immediate penicillin hypersensitivity
- if no alternative available and essential; give 3rd gen OR cefuroxime
- antibiotic associated colitis: more common in 2nd and 3rd gen cephalosporins
Other beta-lactam antibiotics?
- carbapenems and monobactams
Common GI infections?
C.difficile = DIARRHOEA (elderly and women most at risk
Antibiotic associated colitis
- clindamycin (most)
- ampicillin/amoxicillin
- 2nd/3rd gen cephalosporins
- quinolones
Which antibiotics can cause antibiotic-associated colitis?
- clindamycin (most)
- ampicillin/amoxicillin
- 2nd/3rd gen cephalosporin
- quinolones
Treatment of GI infections length?
10-14 days
Treatment of first episode of mild to moderate GI infection?
Oral metronidazole
Treatment of subsequent episodes/severe infections/unresponsive to metronidazole?
Oral vancomycin/ fidoxamicin
What is contraindicated in GI infections?
Loperamide
Common cardiovascular infection?
Endocarditis
Endocarditis treatment ?
Amoxicillin +/- low dose gentamicin
- vancomycin in MRSA/penicillin allergy
- flucloxacillin in staphylococci
- benzylpenicillin in streptococci
Common respiratory infections?
Community acquired pneumonia (CAP)
Hospital acquired pneumonia (HAP)
CAP treatment duration ?
7 days (14-21 days if staphylococci)
Mild CAP treatment ?
Amoxicillin
Alternatives: clarithromycin or doxycycline
Moderate CAP treatment?
Amoxicilin + clarithromycin OR doxycline alone
High severity CAP treatment ?
Benzylpenicillin + clarithromycin/doxycyline
- add flucloxacillin if staphy suspected
- add vancomycin if MRSA suspected
What can be added if staphylococci is suspected ?
Flucloxacillin
What can be added if MRSA suspected ?
Vancomycin
HAP treatment duration?
7 days
Early onset <5 days HAP treatment?
Co-amoxiclav or cefuroxime
Severe or >5days HAP treatment ?
Antipseudomonal penicillin OR broad spectrum cephalosporin or quinolone
- add vancomycin for MRSA
- add aminoglycoside for pseudomonas aeruginosa
Antipseudomonal penicillin?
Piperacillin with tazobactam
Ticaricillin with clavulanic acid
*aminoglycoside also antipseudomonal)
Common nervous system infections?
Meningitis/meningococcal septicaemia
non-blanching rash
Meningitis/meningococcal septicaemia causative agent?
Neisseria meningitis
Meningitis initial empiral treatment ?
- Benzylpenicillin
- cefotaxime if penicillin allergy
- chloramphenicol if immediate penicillin allergy
Common musculoskeletal infection?
Osteomyelitis (bone infection)
Osteomyelitis treatment ?
- Flucloxacillin
- Clindamycin if penicillin allergy
- Vancomycin if MRSA
Common eye infection?
Conjunctivitis - chloramphenicol
Common skin infections?
Impetigo
Cellulitis
Animal and human bites
MRSA
Common skin infections causative agent?
Staphylococci aureus
Impetigo treatment ?
Fusidic acid 7 days if small areas affected
Flucloxacillin for 7 days if widespread
Cellulitis treatment?
Flucloxacillin
Animal and human bites treatment ?
Co-amoxiclav OR
Doxycyline + metronidazole
MRSA treatment (skin and soft tissue?
Tetracycline OR
Sodium fusidate + rifampicin
Alt; clindamycin
If severe; glycopeptide or if unsuitable linezolid
Common oral infections?
- gingivitis: acute necrotising ulcerative
- periapical/periodontal abcess: periodontitis, pericoronitis
Oral infections treatment ?
Dental infections are generally treated with metronidazole 200mg TDS for 3 days
Alternative: amoxicillin OR doxycycline for periodontitis
[change antibiotic if no response in 48 hours penicillin or macrolide with metronidazole]
Common ear nose and oropharynx infections?
- throat infection
- sinusitis
- otitis externa
- otitis media
Throat infection causative agent?
Steptococci
Otitis externa causative agent?
Staphylococci aureus
Throat infection treatment?
Phenoxymethylpenicillin
- if severe benzylpenicillin
- clarithromycin if penicillin allergic
Sinusitis treatment ?
Amoxicillin OR clarithromycin OR doxycyline
Otitis externa treatment?
Flucloxacillin
- clarithromycin if penicillin allergic
Otitis media treatment ?
Amoxicillin
- clarithromycin if penicillin allergic
- treat if systemically unwell
- treatment is given if there is no improvement after 72 hours or earlier if systemic symptoms, mastoditis, bilateral otitis media in under 2 years
Anti-tuberculosis drugs: initial phase?
(2 months)
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
(RIPE)
Continuation phase anti-TB drugs?
4 months
Rifampicin
Isoniazid
Rifampicin key points?
- enzyme inducer (do not use oral contraceptives - insert IUD)
- counselling: reports signs of hepatotoxicity
- colours soft contact lenses and urine red/orange
Isoniazid key points ?
- enzyme inhibitor
- counselling: report signs of hepatotoxicity
- peripheral neuropathy; overcome by concomitant pyridoxine
Pyrazinamide key points?
Hepatotoxitiy
Ethambutol key points?
counselling: visual changes; report immediately
Itraconazole side effects and interactions?
- Anti-fungal
- side effects: heart failure and hepatotoxicity
- interactions: antacids, needs acidic pH for greater absorption
Oral ketoconazole MHRA warning?
Risk of fatal hepatotoxicity is greater than the benefit of treating fungal infections. Refer back prescriptions
Voriconazole side effects?
Photoxicity and hepatotoxicity (causes pre-malignant lesions or skin cancer - avoid direct sunlight and sunlamps. Use high factor spf, and carry alert card)
What is amphoteracin B used for and what are its side effects?
SERIOUS FUNGAL INFECTIONS
Side effects: nephrotoxicity. Anaphylaxis with IV preps - do a test dose and monitor for 30 mins.
*specify brand: not interchangeable
What is used to treat candidias (thrush)?
ORAL
- nystatin (POM) or miconazole (daktarin oral gel)
VULVAL OR VAGINAL
- oral fluconazole OR topical imidazole e.g. clotrimazole
What is tinea and how is it treated?
Fungal infection on the skin
TINEA CAPATIS, CORPORIS (ring worm), CRUIS AND PEDIS
- miconazole or clotrimazole or terbinafine (for athletes foot)
FUNGAL NAIL INFECTION
- amorolfine
What is used for viral infection herpes simplex?
ACICLOVIR
- herpes simplex can affect lips, mouth and eyes
What is used for the prophylaxis of influenza (viral infection)?
OLSELTAMIVIR
- prophylaxis, reduces symptoms by 1 day
- for at risk groups: 65+, diabetes mellitus, immunocompromised etc start withun 48hours of symptoms or without symptoms on exposure
What is used for bite prevention when in countries with malaria?
- NETS impregnated with permethrin is most effective
- DEET 20-50%
- Applied to skin e.g. spray/lotion
- safe and effective in adults and children above 2 months
- apply suncream first and use at least spf 35-50; DEET reduces the spf
- 50% provides longest protection
- long sleeves and trousers after dusk
- asplenic/pregnant women should avoid travel to malarious zones
is chemopropylaxis absolute in antimalarials?
not absolute - breakthrough malaria can occur
Antimalarial prophylaxis regimen?
- malarone (atovaquone and proguanil)
- chloroquine only
- chloroquine + proguanil (proguanil occasionally used alone)
- mefloquine
- doxycycline
Doxycline specific counselling for malaria prophylaxis?
- take 1-2 days before entering endemic area and continued for 4 weeks after leaving
- protect your skin from sunlight - even on a bright but cloudy day. do not use sunbeds
- do not take indigestion remedies, or medicines containing iron or zinc, 2 hours before or after you take this medicine
- capsules should be swallowed whole with plenty of fluid during meals while sitting or standing
Mefloquine side effects?
- SERIOUS NEUROPSYCHIATRIC REACTIONS
- psychosis, suicidal ideation and suicide reported
- prodromal symptoms for a serious event = abnormal dreams, insomnia, nightmares, depression, anxietym restlessness, confusion
- counselling: stop and seek immediate medical attention to replace with alternative antimalarial, if neuropsychiatric effects occur
- containdicated in patients with a history of psychiatric disorders (including depression) or convulsions
Mefloquine and driving?
- dizziness and disturbed sense of balance - can persist up to several months after stopping; mefloquine has a long half life
Which antimalarial regimen?
- Choose high risk regimen for whole journey
- settled immigrants in UK rapidly lose immunity acquired whilst previously living in malarious area
Length of antimalarial prophylaxis ?
BEFORE TRAVEL
- usually 1 week before
- exceptions: mefloquine 2-3 weeks,
- malarone and doxycline 1-2 days
AFTER TRAVEL
- usually 4 weeks after
- exceptions: 1 week after
Long term antimalarial prophylaxis? (>5years)
> 5years chloroquine and proguanil
Long term antimalarial prophylaxis? (2 years)
Doxycycline
Long term antimalarial prophylaxis? (1 year)
Mefloquine, malarone
What antimalarials prophylaxis should patients with epilepsy avoid?
- chloroquine and mefloquine (affects seizure threshold)
What antimalarials prophylaxis should patients with renal impairment avoid?
- proguanil
- malarone and chloroquine if eGFR <30ml/min (severe)
- choose doxycycline or mefloquine
What antimalarials prophylaxis can be given in pregnancy?
- give cholorquine and proguanil
- 5mg folic acid is given with proguanil
- doxycycline is contra-indicated
- avoid mefloquine (advised by manufacturer
- avoid malarone (if there is no alternative may give in 2nd or 3rd trimester)
When should antimalarial prophylaxis be started ? *on warfarin???
- 2-3 weeks before
- INR should be stable before departure
- monitor INR before, 7 days after starting and after completing the course
- for prolonged stays check INR regularly in visiting country
What should you do with any illness that occurs within a year after being in malarial region?
- see GP immediately and specifically mention malaria exposure
- especially the first 3 months of return from malarial region
Malaria treatment?
- quinine
- malarone
- riamet (artemether and lumefantrine) (top 3: falciparum malaria)
- chloroquine (non-falciparum malaria)
How is quinine used ?
- standby treatment of malaria
- take only if you cannot access medical care in 24 hours of fever onset
- given with written instructions that urgent help is required if fever >38, 7 days or more after arriving in malarious zone
Which antibiotics should you avoid in MRSA infections?
QUINOLONES (innate resistance)
Interaction between ciprofloxacin and theophylline?
Pk and Pd interaction: ciprofloxacin is an enzyme inhibitor and causes theophylline toxicity: theophylline side effects is convulsions
What can NSAIDS induce?
convulsions
Which antibiotics cause photosensitivity ?
Tetracyclines (demeclocycline and doxycycline)
* and others
Which antibiotics are an alternative for penicillina)
Macrolides (azithromycin, clarithromycin, erythromycin, and roxithromycin)
Which macrolide has the most GI side effects?
Erythromycin