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Flashcards in Infection Deck (99)
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1
Q

Which antibiotics are safest in pregnancy?

A

Penicillins and cephalosporins.

2
Q

What are the red flags of sepsis?

A
lactate ≥2mmol
systolic BP<90mmHg (or dop >40mmHg)
HR≥130
RR≥25
anuria (signs of AKI)
3
Q

How is sepsis treated?

A

antibiotics within 1 hour (broad spec)
Adjust antibiotics when samples come back
IV fluids, inotropes, vasopressors

4
Q

What drugs commonly cause c.diff?

How is it treated?

Which medicines should be stopped?

A

Clindamycin,
broad spectrum antibiotics (amox, co-amox, cipro)
Treated with: fidaxomycin, metronidazole, vanc for 10-1 4 days.

Stop any PPIs/ stomach acid suppressing drugs- they lead to proliferation of c.diff.
NOTE: loperamide is contraindicated.

5
Q

How is CAP treated depending on severity?

A

Low severity:
Amox 7 days.
Clarith 7 days (if pen allergic or if atypical suspected)
If staphylococcus suspected, fluclox for 14-21 days.

Moderate severity:
Amox + clarith OR doxy alone. 7 days/ 14-21 days if staph

High severity:
Benzylpen+ clarith OR benzylpen + doxy
Co-amox + clarith OR cefuroxime + clarith if gram negative, comorbidities, in nursing home

**For all, 14-21 days if staph and add vanc/teic if MRSA.

6
Q

How is HAP treated?

A
Early onset (<5 days after admission)
Co-amox OR cefuroxime 7 days

LAte onset (>5 days after admission)
1st line- Piptaz
2nd line- cephalosporin (ceftazidime) OR quinolone

**If MRSA add vanc/teic. If p.aeruginosa, add gent

7
Q

What are examples of aminoglycosides?

A

Gent, amikacin, streptomycin, neomycin

IV (except neomycin)

8
Q

What is a major contraindication of aminoglycosides?

A

Myasthenia gravis - they impair neuromuscular transmissions and worsen it.

9
Q

What are some important side effects of aminoglycosides?

Can they be used in pregnancy? renal impairment?

A

Nephrotoxicity- monitor
Ototoxicity

No for pregnancy- maybe yes in first trimester
yes for renal- Increase dosing interval/ dose itself

10
Q

Do you use actual, adjusted or ideal body weight to calculate aminoglycoside dose?

A

Ideal body weight

11
Q

How is the aminoglycoside dose adjusted based on levels?

A
Peak levels (1 hour post administration)
If high, reduce DOSE
Trough levels (pre-dose)
If high, increase dosing INTERVAL
12
Q

Which amino glycoside is too toxic for IV use?

A

Neomycin- Oral ONLY

Used for bowel sterilisation pre surgery- not absorbed

13
Q

What is the MRA warning associated with gentamicin?

A

Potential histamine related adverse effects (itching, SOB, flushing, increased HR) with some batches.

14
Q

Which antibiotics can cause false positive urinary glucose and false positive Coombs test?

A

Cephalosporins

15
Q

What can ceftriaxone react with?

A

Calcium.
Forms a precipitate with collects in gall bladder or urine- STOP if symptoms.
NOT to be given with TPN or infusions containing calcium.
Injection only.

16
Q

What are beta-lactamase inhibitors and what do they do?

A

They prevent breakdown of beta lactates by bacteria and reduce resistance.
They are given in combination with beta lactams.

Examples: avibactam, tazobactam, clavulanic acid

17
Q

What are examples of glycopeptides?

What type of bugs do they target?

A

vancomycin and teicoplanin

Gram +, anaerobes

18
Q

What are some key side effects of glycopeptides?

What is the main thing to avoid when administering them and why?

A

Nephrotoxicity
Ototoxicity

AVOID rapid infusion- risk of anaphylaxis or red man syndrome

19
Q

Which antibiotics are used to target MRSA?

A

vanc/ teic

20
Q
What class of drug is clindamycin?
When should it be avoided / stopped?
A

Lincosamides.
Diarrhoeal states- leads to antibiotic associated colitis which can be fatal.
Stop if diarrhoea occurs with use- c diff.

21
Q

What is the treatment available OTC for chlamydia?

What are the requirements for sale?

A

Azithromycin 1g stat
Max 1g sold for CONFIRMED chlamydia
Patients 16 and over only.

22
Q

What can carbapenems (such as meropenem) cause?

A

CNS effects (risk of seizures) especially if renal impairment.

23
Q

What is the occurrence of allergic reaction vs true anaphylaxis with penicillin use?

A

1-10% have allergic reactions

Only 0.05% true anaphylaxis

24
Q

Which penicillin is penicillin G?

Which one is penicillin V?

A

Benzylpen is penicillin G (IV only)

Phenoxymethylpenicillin is penicillin V (oral only)

25
Q

What is a notable side effect of clavulanic acid?

A

Cholestatic jaundice and acute liver injury.
Especially in men and those over 65.
Co-amox should only be used for max 14 days.

26
Q

Which antibiotics should be taken on an empty stomach?

A

Fluclox, phenoxymethylpenicillin

27
Q

What is a notable side effect of penicillins?

A

Hepatic disorders- cholestatic jaundice/ hepatitis

Can occur up to 2 months after treatment

28
Q

What is the contraindication of quinolones such as ciprofloxacin?

A

History of tendonitis- can cause tendon damage.
Those over 60 and on corticosteroids are more prone.

Epilepsy- lowers seizure threshold especially when used with NSAIDs

29
Q

What are the MHRA alerts regarding fluoroquinolones?

A

(March 2019) New restrictions due to rare reports of disabling side effects such as tendon rupture, muscle and joint pain. Stop immediately. Only use them in severe infections now.

(Nov 2018) Risk of aortic aneurysm and dissection. Sign are sudden severe abdominal, chest or back pain.

30
Q

What are some other notable side effects of quinolones?

A

Photosensitivity- discontinue
QT prolongation
CNS effects such as psychosis- discontinue

31
Q

What is a major side effects of sulphonamides such as sulfamethoxazole (in co-trimoxazole)

A

Blood disorders

32
Q

Which antibiotics may cause concern if a patient complains of headaches or visual disturbances?

A

Tetracycline- can cause raised intracranial pressure- discontinue.

33
Q

When should tetracyclines be avoided and why?

A

Children <12, pregnancy and breastfeeding

Chelates calcium in bones and teeth causing staining

34
Q

Which tetracyclines can be taken with milk as the absorption is not reduced?

A

Remember: Does Like Milk

Doxycycline, Lymecycline, Minocycline

35
Q

What side effect is chloramphenicol associated with?

A

Grey baby syndrome- avoid in children and pregnancy

Can cause serious haematological side effects if given systemically

36
Q

Which antibiotic affects the test for INR and prothrombin time?

A

Daptomycin

37
Q

What is rifaximin used for?

A

Traveller’s diarrhoea and hepatic encephalopathy

38
Q

Which medicines can be used for leprosy?

A

Dapsone, rifampicin, clofazimine

39
Q

How is MRSA treated?

A

Skin/soft tissue:
Tetracycline / rifampicin + fusidic acid
Clindamycin

If severe/ systemic:
Glycopeptide/ linezolid

40
Q

How is active TB managed?

A

Initial phase: 4 drugs **REMEMBER RIPE to RI
rifamipicin + pyrizinamide + ethambutol + isoniazid (+pyridoxine for isoniazid- induced neuropathy) for 2 months minimum (establish sensitivities)

Continuation phase: 2 drugs
Rifampicin + isoniazid (+ pyridoxine as above) for 6 months.

41
Q

Which medicine can be used for TB in isoniazid resistance?

When can it not be used?

A

Streptomycin

Pregnancy: risk of auditory and vestibular damage.

42
Q

When should supervised regimens of TB (DOT- directly observed therapy) be implemented?

What does it involve?

A

Supervised whilst swallowing tablets at least 3 days a week.

Offer to patients with MDR/ XDR TB, denial of TB diagnosis, adherence issues, psychiatric issues, previous TB treatment.

43
Q

How is extra pulmonary TB treated differently to regular TB with CNS/ pericardial involvement?

A

The initial phase is the same but the continuation phase is prolonged for TEN months.
High dose dex/pred initially and withdrawn over 4-8 weeks.

44
Q

How is latent TB treated? Who needs to be treated?

A

Treat immunocompromised patients and patients under 65 who are not at risk of hepatotoxicity or other side effects of the drugs.

Treatment: Isoniazid (+ pyridoxine) for 6 months OR isoniazid (+pyridoxine) + rifampicin for 3 months

45
Q

What medicines should be used in TB in extreme hepatotoxicity?

A

Ethambutol and streptomycin (as they have lowest hepatotoxicity risk) + levofloxacin.

46
Q

What are MDR and XDR TB?

A

MDR TB- resistant to isoniazid and rifampicin

XDR- TB- resistant to isoniazid, rifampicin, + 1 of the second line drugs (amikacin, kanamycin, capreomycin)

47
Q

Which antimycobacterial is contraindicated in a patient with poor vision?

A

Ethambutol- can cause visual impairment. Check eyes before starting treatment.

NOTE: ethambutol can also cause flatulence

48
Q

What is a common side effect of anti-TB drugs?

A

Hepatotoxicity. Don’t change unless serious liver toxicity.

49
Q

Which antimycobacterial is contraindicated in a patient with gout?

A

pyrazinamide- it exacerbates gout

50
Q

How is UTI treated?

How is this differ if the patient is pregnant?

A

1st line: trimethoprim or nitrofurantoin
2nd line: amox, cephalosporins

If pregnant, use penicillins or cephalosporins. AVOID trimethoprim in first trimester and nitrofurantoin at term.

3 days in women, 7 days in men

51
Q

Can you use quinolones in pregnancy?

A

No- causes arthopathy

52
Q

Nitrofurantoin cannot be used in renal failure. What is the cut off?

A

eGFR <30ml/min

53
Q

Which antifungal is INeffective against fungal infections of the CNS?

A

caspofungin

54
Q

What is a common side effect of the triazole antifungals? (e.g fluconazole, itraconazole, posaconazole)

Which one requires an acidic gastric environment?

A

Hepatotoxicity

Itraconazole neds acidic environment for absorption.

55
Q

Which anti-fungal must be prescribed by brand?

Which formulations are less toxic?

A
Amphotericin
Lipid formulations (e.g ambisome) is less toxic and hence less side effects but are more expensive.
56
Q

What drug is used for pneumocystis pneumonia (PCP)?

A

co-trimoxazole

57
Q

How are threadworms treated?

A

Mebendazole 100mg for a single dose.
Can be repeated after 2 weeks- reinfection is common
All members of the household must be treated
Hygeine measures are essential

58
Q

Which antibiotics are usually used for protozoal infections such as amoebas?

A

Metronidazole and tinidazole. - remember they cover atypicals.

59
Q

What are non-pharmacological methods of malaria prophylaxis?

A

Long sleeved baggy clothing
Mosquito nets impregnated with permethrin
DEET 20-50% (2 months old and over)

60
Q

How long before travel are the different malaria prophylaxis medications commenced?

A

Generally a week
2-3 weeks for mefloquine
1-2 days for malorone and doxyxycline

61
Q

What is the maximum length of treatment for malaria prophylaxis?

A

Generally up to a year

Doxycycline up to 2 years

62
Q

How long should malaria prophylaxis be continued for after leaving the endemic area?

A

4 weeks

1 week for malorone

63
Q

Which antimalarial drugs are unsuitable in patients with epilepsy?

A

mefloquine is contraindicated

chloroquine is unsuitable

64
Q

How is malaria prophylaxis managed in pregnant women if travel cannot be avoided?

A

Chloroquine + proguanil at usual dose ( with folic acid 5mg in first trimester)

Doxycycline is C/I but CAN be used if no alternative and entire course can be completed before 15 weeks gestation.

Malorone also CI but can be considered in second and third trimesters if no other options.

65
Q

How is falciparum malaria managed?

A

1st line- quinine 5-7 days THEN doxy/ clindamycin 7 days

2nd line- Malorone (atovaquone + proguanil) OR riamet (arthemether + lumefantrine)

In difficult cases, IV artesunate can be used for named patients.

In pregnancy: give quinine then clindamycin.

66
Q

How is non- falciparum malaria managed?

A

1st line: chloroquine

If chloroquine resistant: malorone/ quinine/ riamet

67
Q

When does a ‘radical cure’ need to be given in non- falciparum malaria?

How does this differ in pregnancy?

A

In p.rivax and p. ovulae, a radical cure is needed to destroy parasites in the liver thus prevent relapses.
Give primaquine for 14 days after antimalarial drug.

In pregnancy, postpone primaquine until after birth. continue chloroquine weekly for the rest of the pregnancy.

68
Q

What is in malorone?

A

atovaquone + proguanil

69
Q

Which antimalarial can cause eye toxicity with prolonged use and at doses exceeding 2.5mg/kg/day?

A

Chloroquine

70
Q

Can you continue hydroxychoroquine for another indiciation, if starting the patient on chloroquine?

A

yes

71
Q

What are common side effects of antimalarials?

A

CNS side effects: abnormal dreams, depression

Possible blood disorders

72
Q

What is the MHRA alert associated with quinine?

A

Can cause dose dependent QT prolongation

73
Q

Which antimalarial is contraindicated in eye disorders and tinnitus?

A

Quinine

74
Q

What parameters must be determined before starting treatment for chronic hepatitis C?

A

Genotype of hep c virus

Viral load

75
Q

What are the MHRA alerts associated with antivirals for hep C such as elbasvir with grasoprevir?

A

1- May affect efficacy of vitamin K antagonists, monitor INR closely

  1. Can cause hepatitis B reactivation in patients who are co infected with both Hep C and help B
76
Q

When should most antivirals used for hepatitis be discontinued?

A

If they cause deterioration in liver function, hepatic steatosis (fatty liver), or unexplained lactic acidosis.

77
Q

Which antivital is containdicated in severe psychiatric problems in children and severe or unstable heart disease?

A

Ribavarin

78
Q

Do antivirals affect pregnancies?

A

Yes- teratogenic

Use effective contraception during and for a few weeks after treatment.

79
Q

Men should avoid fathering a child while taking and 6 months after stopping which antifungal?

A

Griseofulvin

80
Q

What is varicella zoster virus?

How is it managed?

A

Chicken pox
It is healthy in children between 1 month and 12 years- goes away on its own, calamine, pain relief
AVOID ibuprofen as it can lead to serious skin and soft tissue damage and can lead to amputations.

In neonates and adults, treat with antivirals.

81
Q

What is herpes zoster?

How is it managed?

A

Shingles
Symptoms: unilateral rash on trunk, burning pain
Start antivirals within 72 hours of rash for 7-10 days

82
Q

What drugs are used for the prevention and treatment of CMV?

A

ganciclovir
valaciclovir (prophylaxis post renal transplant)
valganciclovir (post solid organ transplant from CMV+ donor)
foscarnet (in AIDS patients) - very toxic + nephrotoxic.

83
Q

What are the most common side effects of antiretrovirals?

A

osteonecrosis
lipodystrophy
immune reconstitution syndrome

84
Q

What drugs are used in HIV for pre-exposure prophylaxis?

A

emtricitabine + tenofovir

85
Q

What is the treatment for HIV?

A

2 x nucleoside reverse transcriptase inhibitors

AND

non neucleoside reverse transcriptase inhibitor OR boosted protease inhibitor OR integrase inhibitor.

86
Q

Whar are some exampes of nucleoside reverse transcriptase inhibitors?
Which side effect requires treatment cessation?

A

emitricitabine, renofovir, zidovudine

STOP if lactic acidosis

87
Q

What are some examples of non neucleoside reverse transcriptase inhibitors?

A

efavirens, etravirine, nevirapine

88
Q

Which antiretroviral commonly causes psychiatric + CNS disorders?
What should be done about this?

A

Efavirens

Taking the dose at bedtime reduces this.

89
Q

What are some boosted protease inhibitors?

What does the ‘boosted’ mean?

A

ritonavir, darunavir

Ritonavir in low doses ‘boosts’ the activity of other protease inhibitors and increases their plasma concentration whilst having no antiviral activity itself at such a low dose.

90
Q

Which antiretroviral should be discontinued if pancreatitis is confirmed?

A

ritonavir

91
Q

What are some examples of integrate inhibitors?

A

raltegravir, dolutegravir

92
Q

What is the MHRA alert regarding dolutegravir?

A

Neural tube defects in infants if used in pregnancy- AVOID and use an alternative.

93
Q

What is cobicistat?

A

Pharmaconetic enhancer- No antiretroviral activity itself but it boosts the effects of some antivirals such as the protease inhibitors.

94
Q

What treatment is available for influenza?

Include doses.

A

Oseltamavir
treatment- 75mg BD for 5 days (10 days if immunocompromised)
prophylaxis- 75mg OD Reduce to 30mg if egfr <30ml/min

Zanamivir (inhalation)

95
Q

When might oseltamivir be ineffective?

A

In neonates

96
Q

What is a notable side effect of oseltamivir?

A

Neurological and psychiatric disorders.

97
Q

What is a major caution for use of zanamivir?

A

Pulmonary disease- risk of bronchospasm.

AVOID in severe asthma

98
Q

What drug can be used for diabetic foot infections?

A

Clindamycin

99
Q

What do you know about linezolid?

A

Can cause blood disorders- discontinue
can cause optic neuropathy if used >28 days
It is related to MAOIs- patients should avoid tyramine rich foods whilst taking it.