Infections Flashcards
What is the general rule of thumb for treating Staphylococci infections?
Flucloxacillin
What is the general rule of thumb for treating MRSA infections?
Vancomycin
What is the general rule of thumb for treating Streptococci infections?
Benzylpenicillin and Phenoxymethylpenicillin
What is the general rule of thumb for treating anaerobic infections?
Metronidazole
What is the general rule of thumb for treating pseudomonas infections?
Gentamicin
What age are tetracyclines contraindicated for?
Under 12
What do quinolones cause?
Arthropathy (joint diseases e.g. arthritis) - mainly in children
Which antibiotics are hepatotoxic?
Rifampicin and tetracyclines
Which antibiotics are nephrotoxic?
Tetracyclines and nitrofurantoin in eGFR <45
Glycopeptides and aminoglycosides are also nephrotoxic
What bacteria is Leprosy (Hansen’s disease)?
Mycobacterium leprae
Which bacteria causes Lyme disease?
Borella burgdorferi
What is the main characteristic of Lyme disease?
erythema migrans rash (bull’s eye pattern)
Usually visible 1-4 weeks after bite
Which other symptoms present with Lyme disease?
Non-facial (non-organ related) symptoms e.g. fever, swollen glands, malaise, headache, cognitive impairment or paraesthesia (pins and needles)
others: focal symptoms (related to at least 1 organ) e.g. neurological (affecting cranial nerves, peripheral and CNS), joints (Lyme arthritis), cardiac (Lyme carditis) and skin manifestations
What is the treatment for erythema migrans rash with or without non-focal symptoms in Lyme disease?
1st line: oral doxycycline
2nd line: oral amoxicillin
if both can’t be given then oral azithromycin
What is the treatment of cranial nerve or peripheral nervous system involvement in Lyme disease?
1st line: oral doxycycline
2nd line: oral amoxicillin
What is the treatment for symptoms of CNS involvement in Lyme disease?
1st line: IV ceftriaxone
2nd line: oral doxycycline
What is the treatment for Lyme arthritis or acrodermatitis chronica atrophicans (almost like bruising on the skin)?
1st line: oral doxycycline
2nd line: oral amoxicillin
3rd line: IV ceftriaxone
What is the treatment for Lyme carditis in haemodynamically stable patients?
1st line: oral doxycycline
2nd line: IV ceftriaxone (this is the first line treatment if the patient is haemodynamically unstable then doxycycline when stable)
What Is the treatment pathway for skin and soft-tissue infections caused by MRSA?
1st line: tetracyclines alone OR a combination of rifampicin and fusidic acid
2nd line: clindamycin alone
3rd line: glycopeptide - vancomycin in severe cases
4th line: Linezolid in severe cases
If initial treatment fails: fusidic acid or rifampicin with glycopeptide
Complicated cases: tigecycline with daptomycin
What is the treatment of bronchiectasis from MRSA?
Tetracycline or clindamycin
What is the treatment for pneumonia from MRSA?
Glycopeptide or Linezolid
But needs to be given with an antibiotic that covers gram-negative as linezolid only covers gram-positive
What is the treatment for UTI from MRSA?
Oral doxycycline, trimethoprim, ciprofloxacin, or co-trimoxazole
What is the treatment for septicaemia (blood poisoning) associated with MRSA?
Glycopeptide
What is the treatment for prophylaxis of MRSA in surgery?
Vancomycin or teicoplanin alone or in combination with one another
Which bacteria cause UTIs in sexually active women?
Staph saprophyticus
Which bacteria generally causes UTIs?
E.coli
What is considered a recurrent UTI?
2 episodes in 6 months
What is the treatment for UTIs in non-pregnant women?
Either nitrofurantoin if eGFR >45ml/min OR trimethoprim
2nd line: nitrofurantoin (if not used 1st line), pivmecillinam, fosfomycin or amoxicillin
What is the treatment for UTIs in pregnant women?
1st line: nitrofurantoin if eGFR >45ml/min
2nd line: amoxicillin
asymptomatic bacteriuria: nitrofurantoin, amoxicillin or cefalexin (500mg BD 7/7) based on recent culture
What is the treatment for UTIs in men?
Trimethoprim or nitrofurantoin
2nd line: consider alternative diagnosis e.g. pyelonephritis (kidney infection) or prostatitis (inflammation of prostate)
What is the treatment for prostatitis?
1st line: ciprofloxacin or ofloxacin
2nd line: Levofloxacin, or co-trimoxazole
Why severely unwell - IV of:
- cefuroxime
- ceftriaxone
- ciprofloxacin
- gentamicin
- amikacin
What is the treatment of pyelonephritis in non-pregnant women and men?
1st line: Cefalexin, or ciprofloxacin
If sensitivity is known: co-amoxiclav or trimethoprim.
What is the treatment of pyelonephritis in pregnant women?
1st line: cefalexin
In severe cases: IV Cefuroxime
What is the treatment for recurrent UTIs in non-pregnant women?
1st line trimethoprim or nitrofurantoin
2nd line: amoxicillin or cefalexin (125 ON or 500mg 1 dose)
What is the treatment for recurrent UTIs in post-menopausal women?
vaginal oestrogen at the lowest effective dose and review in 12 months b
What is the treatment for catheter-associated UTI in pregnant women?
1st line: cefalexin
2nd line: IV cefalexin
What is the treatment for catheter-associated lower UTI in non-pregnant women and men?
1st line: amoxicillin, trimethoprim or nitrofurantoin
2nd line: pivmecillinam
What is the treatment for catheter-associated upper UTI in non-pregnant women and men?
1st line: cefalexin, ciprofloxacin, co-amoxiclav or trimethoprim
Which bacteria causes Tuberculosis?
Myobacterium tuberculosis (M. tuberculosis, M. africanum, M. bovis or M. microti)
What are the clinical signs of tuberculosis?
Persistent fever
Weight loss
Drenching night sweats
Dry cough
What is the initial treatment for tuberculosis with counselling points for each drug?
Two months of RIPE:
RIFAMPICIN: (enzyme inducer - do not use an oral contraceptive, use IUD)
- counselling: report signs of hepatotoxicity, may colour soft contact lenses and may turn urine an orange/red colour
ISONIAZID: (enzyme inhibitor)
- counselling: report signs of hepatotoxicity, which may cause peripheral neuropathy which is overcome by concomitant pyridoxine (10-20mg daily)
PYRAZINAMIDE:
- counselling: report signs of hepatotoxicity
ETHAMBUTOL:
- counselling: report visual changes immediately
What is the treatment of the continuation phase of tuberculosis?
4 months of 2 agents:
- rifampicin
- isoniazid
(10 months in active tuberculosis of CNS with or without spiral involvement)
What is the treatment regimen when there’s drug resistance to isoniazid in tuberculosis?
Initial phase: 2 months of
- Rifampicin
- Pyrazinamide
- Ethambutol
Continuous phase: 7 months of
- Rifampicin
- Ethambutol
What is the treatment regimen when there’s drug resistance to pyrazinamide in tuberculosis?
Initial phase: 2 months of
- Rifampicin
- Isoniazid (with pyridoxine hydrochloride)
- Ethambutol
Continuous phase: 7 months of
- Rifampicin
- Isoniazid
What is the treatment regimen when there’s drug resistance to ethambutol in tuberculosis?
Initial phase: 2 months of
- Rifampicin
- Pyrazinamide
- Isoniazid
Continuous phase: 4 months of
- Rifampicin
- Isoniazid
How do you treat latent TB?
6 months of isoniazid alone OR
Rifampicin and isoniazid for 3 months
How are immunocompromised (HIV or transplant) patients treated for tuberculosis?
They are treated with first-line and reviewed but for a maximum of 6 months if they have HIV unless there is CNS involvement then this is increased to 12 months
How do you treat extrapulmonary TB?
Initial treatment for 2 months
continuation treatment for 10 months
High dose of prednisolone or dexamethasone then slowly reduce over 4-8 weeks
How do you treat pericardial TB?
Offer a high dose of prednisolone at the same time as the initial treatment and withdraw after 2-3 weeks
How do you treat children with TB?
The same way as adults but monitor ethambutol closely as it is more difficult to test and confirm eyesight
Name 4 triazole antifungals
Triazole antifungals work in the prevention and systemic treatment of fungal infections
- Fluconazole - well absorbed
- Itraconazole - absorbed in acidic environments (stomach), hepatotoxicity common with this drug
- Posaconazole - used after the above two failed
- Voriconazole - broad spectrum for life-threatening conditions
What is the safety warning and main interaction for itraconazole?
cautioned use in patients at high risk of heart failure and hepatotoxicity
Interacts with antiacids as requires acidic pH to be absorbed
what are the safety warnings with voriconazole?
Photosensitivity
Hepatotoxicity
What are the 5 imidazole antifungals?
Used in local treatment of vaginal candidiasis and for dermatophyte infections
Clotrimazole
Econazole nitrate
Ketoconazole
Tioconazole
Miconazole
What is the MHRA warning for oral ketoconazole?
The risk of hepatotoxicity is greater than the benefit of treating fungal infections
Oral ketoconazole for Cushing’s syndrome and topical products containing ketoconazole are not affected by this advice.
What are the two polyene antifungals?
Amphotericin - IV for systemic infections
Nystatin
These are not absorbed when given orally
What is the MHRA warning and safety warning for amphotericin?
Warning of fatal overdoses when mistaking non-lipid and lipid formulations (AmBisome), prescribe by brand as not interchangeable
Associated with nephrotoxicity: anaphylaxis with IV preparations - do a test dose and monitor for 30 mind
What is flucytosine used for?
used in combination with amphotericin for systemic candidiasis and cryptococcal meningitis
What are the cautions for flucytosine?
Can cause bone marrow depression = needs weekly blood counts in prolonged therapy
Can develop resistance = test regularly
What is terbinafine used for?
Fungal nail infections and ringworm where oral treatment is considered appropriate
How do you treat candidiasis if topical preparations have failed?
Fluconazole
If unresponsive - itraconazole
If CNS or invasive - Amphotericin
Resistant - voriconazole
Refractory cases - flucytosine with iV amphotericin
How do you treat cryptococcosis or cryptococcal meningitis?
cryptococcal meningitis: IV infusion amphotericin and IV infusion flucytosine for 2 weeks
THEN oral fluconazole for 8 weeks or until cultures are negative
cryptococcosis: fluconazole only if amphotericin not tolerated
How do you treat mild-to-moderate pneumocystis pneumonia?
1st line: high dose co-trimoxazole
2nd line: atovaquone/ dapsone with trimethoprim by mouth
3rd line: clindamycin and primaquine by mouth but cause considerable toxicity
How do you treat severe pneumocystis pneumonia?
1st line: high dose co-trimoxazole
2nd line: pentamidine isetionate (potentially toxic) - risk of severe hypotension right after treatment
corticosteroids can also be lifesaving
What is the adjunctive therapy if the disease is associated with HIV in moderate-severe pneumocystis pneumonia?
Oral prednisolone for 5 days (alternatively, hydrocortisone parenterally)
- Dose then reduced to complete 21 days of treatment
- corticosteroid should be started at the same time as anti-pneumocystis therapy and no longer than 24-72 hours after
- corticosteroid should be withdrawn before anti-pneumocystis course is complete
What is the treatment for prophylaxis of pneumocystis?
This is given to all patients with history of infection and severely immunocompromised
Do not discontinue if the patient has oral candidiasis, continues to lose weight, or is receiving cytotoxic therapy or long-term immunosuppressant therapy
1st line: co-trimoxazole
2nd line: inhaled pentamidine isetionate is better tolerated than parenteral
3rd line: Dapsone OR atovaquone
How do you treat threadworms?
Treat all members of the family
Single dose of mebendazole then repeat 14 days
- DO NOT give in pregnant women or children under 2
How do you treat roundworm (ascariasis)
Mebenazole for 3 days
If not tolerated = levamisole as a special order
How do you treat tapeworms?
Nicolasmaide (Special order)
- limited to GI side effects
- can give antiemetic before and laxative after to help with the side effects
How do you treat hookworms?
Mebenazole for 3 days
Levamisole for children can be used
What are the side effects of proguanil?
GI side effects - rarely used alone, usually with chloroquine
How do you take proguanil?
1 week before travel and continue treatment for 4 weeks after returning
Can proguanil be given to women who are pregnant?
yes at normal doses
Given with folic acid to avoid neural tube defects
However, not effective in most malarial areas
also safe in breastfeeding patients
What are the cautions and side effects of mefloquine?
Do not use in:
- cardiac conduction disorders
- epilepsy
- psychiatric illness including depression, dizziness
side effects:
- GI
- nightmares
- psychosis
- skin reactions
- vision disorders
How do you take mefloquine?
weekly
2-3 weeks before travel
continue for 4 weeks after returning - licensed for up to 1 year but can be used for 3 years if no signs of harm
Can mefloquine be used in pregnancy and breastfeeding?
Good for high risk countries and if resistant to other drugs
Used in 2nd and 3rd trimester, caution in 1st trimester if benefit is higher than risk
Breastfeeding - risk to patient is minimal
What are the side effects of atovaquone with proguanil hydrochloride?
GI side effects and headaches
How do you use atovaquone with proguanil for malaria?
start 1-2 days before travel and continue for a week after travel
Can atovaquone with proguanil be used in pregnancy and breastfeeding?
Avoid
Can be considered in 2nd and 3rd trimester with folic acid to protect against neural tube defects
Which antimalarials can you use in epilepsy?
doxycycline or atovaquone with proguanil
chloroquine and mefloquine contraindicated
How should patients who take anticoagulants take antimalarials?
Travellers taking warfarin should begin prophylaxis 2-3 weeks before departure
INR should be stabilised before, 7 days after starting and after course
What is the treatment for unknown, mixed or uncomplicated falciparum malaria species?
Artemisinin combination therapy:
Artemether with lumefantrine
Quinine 600mg TDS 5-7 days with or followed by oral doxycycline 200mg OD for 7 days OR clarithromycin for 7 days
- Can be given IV if severely ill and can be given IV or orally in pregnant women but give them clarithromycin instead of doxycycline
Malarone (atovaquone with proguanil) - 4 tablets daily for 3 days - avoid in pregnancy
Riamet (artemether with lumefantrine) - 4 tablets initially, followed by 5 further doses of 4 tablets each at 8, 24, 36, 48 and 60 hours - avoid in pregnancy
What is the treatment for non-falciparum malaria?
Chloroquine
If resistant - malarone of riamet
Radical cure: primaquine for 14 days
In pregnancy: chloroquine or primaquine for radical cure
What antibiotics are contraindicated in children?
Tetracyclines ‘cycline’: avoid in under 12 as it deposits in growing bones and teeth
Quinolones ‘floxacin’ : tendon damage more common in children, only used in certain circumstances
Chloramphenicol: can cause grey-baby syndrome