Infections Lecture 7: Guest Speaker: HIV

Question 1

What is the natural course of HIV virus

Answer 1

Acute infection: increase in amount of virus as you feel flu like symptoms called seroconversion illness (initial increase)

Immune system: helps reduce viral load for period of time, but replication is constant (evens out)

CD4 levels begin to drop as opportunistic infection occurs

Viral load increases as disease progresses

Question 2

Describe what happens in the seroconversion stage of HIV

Answer 2

Person has HIV and develop antibodies to virus

High viral load and CD4 decline

Symptoms: Flu like

Not enough antibodies at this stage to test positive

Question 3

Describe what happens in the asymptomatic stage of HIV

Answer 3

Immune system controls the HIV

CD4 count continues to decrease

Viral load continues to increase

Question 4

Describe what happens in symptomatic stage of HIV and AIDS stage

Answer 4

Physical signs of HIV

Common cold
Chest infection
Skin problems
Fever
Weight loss

DEATH at AIDS stage

Question 5

What sorts of infections are likely to affect you during AIDS

Answer 5

Mycobacterium tuberculosis

Pneumonia

Candidiasis

Herpes Simplex

Question 6

What sort of malignancy is likely to affect you during AIDS

Answer 6

Lymphoma

Kapsi’s sarcoma

Cervical/anal cancer

Question 7

How do you diagnose HIV

Answer 7

HIV immunoassay test for presence of HIV antibodies and p-24 antigen in blood

Then must have confirmatory test for HIV 1 and 2 differentiation assay
HIV nucleic acid test

Question 8

How do you prevent HIV

Answer 8

Condom use

Testing and counselling

Use anti-retrovirals
PRE EXPOSURE PROPHYLAXIS
POST EXPOSURE PROPHYLAXIS

Needle exchange schemes

Question 9

What are the aims of antiretroviral treatment

Answer 9

Achieve and maintain undetectable viral load

Strengthen immune system- increase CD-4 count

Reduce risk of opportunistic infection- if CD-4 count is less than 200 cells per micro litre

Reduce transmission risk

Question 10

What is the mechanism of action of entry inhibitors CCR5 antagonist

Answer 10

Binding prevents the virus from entering immune cells via these receptors

Question 11

What is the mechanism of action of Reverse transcriptase inhibitors (NRTI)

Answer 11

Inhibits enzyme responsible for viral RNA to DNA

Incorporates viral DNA chain leading to chain termination

Binds to active site on reverse transcriptase enzyme

Question 12

What is the mechanism of action of Intergrase inhibitors

Answer 12

Bind to integrase enzymes, prevents integration of viral DNA to host DNA

Question 13

What is the mechanism of action of protease inhibitors

Answer 13

Binds to active site of HIV-1 protease enzyme and prevents maturation of newly formed infectious virons

Question 14

When should you start HIV treatment

Answer 14

When CD4 count is less than 350 cells per microlitre

If patient has hepatitis B or C co-infection, start at high CD4 count

Start in pregnancy regardless

Question 15

What does the BHIVA treatment guidelines recommend you start with?

Answer 15

TRIPLE THERAPY
2 x NRTI treatment + third agent:

Example:
Truvada + Darunavir or ritonavir

Kivexa + efavirenz

Question 16

What does Truvada treatment contain

Answer 16

Tenovir and emtricitabine

Question 17

What does Kivexa treatment cotain

Answer 17

avacavir and lamivudine

Question 18

What do you monitor for in a HIV patient

Answer 18

Well being

Side effects

Blood- liver, renal function, bone profile, lipids and glucose

Weight/BMI

Blood pressure

STI screen/sexual history

Hepatitis B or C marker

Surrogate markers- CD4 marker

Question 19

What is the optimal CD4 count you should try to keep a patient with HIV at

Answer 19

200 or more cells per microlitre

Question 20

What are the common side effects of anti-retroviral drugs

Answer 20

Headache
Nausea, Vomiting
Diarrhoea
Rash
RAISED LFTs

Question 21

What are the specific side effects of Efavirenz, Atazanvir and tenofovir

Answer 21

Efvirenz- abnormal dreams, dizziness and drowsiness

Atazanavir- hyperbilirubinaema (yellowing of skin)

Tenofovir- renal impairment

Question 22

What are the long term side effects of anti retroviral drugs

Answer 22

Fat redistributions- lipohypertrophy and lipoatrophy

Hyperlipidaemia

Hyperglycaemia

Question 23

What is immune reconstitution syndrome

Answer 23

When antiretrovirals are started an overwhelming inflammatory response occurs as T cells that were once surpassed by HIV respond to previously acquired infection

May uncover opportunistic infections such as TB

Question 24

Why do antiretrovirals have common interactions (hint: to do with how it is metabolised)

Answer 24

Protease inhibitors and NNRTIS are metabolised by cytochrome P450 isoenzyme CYP3A4 or CYP2D6

drug interaction Inducer: decreases drug level- failure of treatment

drug interaction Inhibitor: increases drug level- toxicity

Question 25

After a baby is born from a HIV mother, what is the treatment option

Answer 25

28 days of zidovudine treatment

Question 26

What is the post exposure prophylaxis treatment you can give someone after contracting HIV

Answer 26

Truvada: 1 tablet ONCE daily

Raltegravir: 400mg TWICE daily

Question 27

What is the role of the HIV pharmacist (6)

Answer 27

Education- advising patients on treatment

Adherence- identifying problems and barriers to it

management of complex cases- drug resistance, adverse reactions, opportunistic infection, drug interaction

healthy life style advice- smoking cessation

Signposting- support groups

Budget and cost effective prescribing