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Pharmacology (5th year) > Opportunistic Infections > Flashcards

Flashcards in Opportunistic Infections Deck (26):
1

Which infections can be prevented by cotrimoxazole

- Pneumocystis pneumonia
- bacterial pneumonia
- bacteraemia
- toxoplasmosis
- isosporiasis
- malaria

2

Preventative TB therapy in adults

Isoniazid preventative therapy effect in patients on ART (6 months)
- if not on ART, positive Mantoux predicts benefit
- NB, exclude active TB first

3

TB preventative therapy in children

For children with TB contacts
- all children under 5
- HIV-infected children of all ages

4

Alternative prophylaxis for pneumocystis jirovecii

- Dapsone

5

Indications for cotrimoxazole prophylaxis

- WHO stage 3/4
- CD4 <200

6

Duration of cotrimoxazole prophylaxis inadults

- lifelong, unless CD4 count rises to >200 on ART

7

Usual organisms causing bcaterial pneumonia

- strep pneumoniae
- h. influenzae
- staph aureus
- klebsiella
- atypicals

8

Principles of treating serious bacterial infections in HIV/ AIDS

- prompt appropriate empirical antimicrobial
- use a broader spectrum agent
- duration of therpay not well studied
- opportunistic organisms can present like bacterial infection

9

Management of pneumocystis pneumonia

- high dose cotrimoxazole for 21 days
- adjunctive corticosteroids improve outcome

10

Adverse effects of cotrimoxazole

- hypersensitivity reactions
- BM suppression

11

Screening protocol for cryptococcal infection

- screen HIV-infected adults with CD4 <100 (CrAg)
-

12

MOA of cotrimoxazole

- sequential inhibition of enzymes of the folic acid pathway

13

Treament of cryptococcal meningitis

- treate with IV ampho B (1mg/kg/day)and fluconazole (800mg/day) for 2 weeks
- then fluconazole 400mg/day for 8 weeks
- the fluconazole 200mg/day for 12 months

14

AE of amphotericin B

- infusion related fever and rigors (pretreat with paracetamol)
- anaemia and weight loss
- dose-related nephrotoxin (loss of K and Mg) - minimized if well hydrated

15

Pharmacokinetics of fluconazole

- excellent oral bio-availability
- long half-life
- penetrates well into CSF
- 80% excreted unchanged in uringe
- weak CYP450 inhibitor

16

Important factors to consider in cryptococcal meningitis

- most patients have raised ICP
- blindness is not uncommon
- defer ART until 4-6 weeks

17

Treatment of candidiasis

- topical therapy when in oral cavity/ vagina
- fluconazole for refractory cases/ oesophageal involvement

18

MOA of acyclovir

- purine nucleoside analogue
- inhibitor of Herpes DNA polymerase

19

Pharmacokinetics of acyclovir

- poor oral bioavailability
- short plasma half life
- excreted unchanged by kidneys
- well tolerated

20

Important factors in clinical use of acyclovir

- need to be commensed early if immunocomp (<72 hrs for shingles, <24 hrs for recurrent HSV)

21

Syndromic management for genital ulcers

- Add acyclovir to benzathine penicillin if HIV status positive or unknown
- if no response, add azithromycin

22

When does shingles usually occur in HIV?

moderate immune suppression (CD4 350)

23

How does shingles in HIV positive compare to uninfected

- longer duration
- often >1 dermatome
- pain more severe
- higher risk of post-herpetic neuralgia

24

When does CMV infection occur in HIV positive patients?

CD4 <100

25

Treatment of CMV

- IV ganciclovir
- maintenance therapy for eye/CNS

26

Toxicity causes of gancyclovir

BM suppression