ITM 2 The Young Adult Flashcards
What type of virus is HIV
RNA virus
Retrovirus
What is the p24 antigen
Early marker of infection in HIV
Capsid response releases p24 but over time disappears as antigens develop against it
What are nucleoside reverse transcriptase inhibitors
Zidovudine phosphorylated by intracellulae thymidine kinase to form active zidovudine 5-triphosphate
Zidovudine 5-triphosphate terminates viral DNA chain elongation via competition with TMP and incorporation into DNA
Resistance via mutations in reverse transcriptase codons
Non nucleoside reverse transcriptase inhibitors
Efavirenz
- diffuses into cell and binds adjacent to active site of reverse transcriptase, leading to conformation change to inhibit
Different site from NRTIs
What do protease inhibitors do in HIV
Virus takes over the cells and produces new viral proteins. Protease enzyme processes these
HIV viral protease is essential for infectivity
Cleaves viral polyprotein into:
- reverse transcriptase
- integrase
- protease
- structural proteins
What are fusion inhibitors
Eg enfuvirtide Similar to segment of viral glycoprotein gp41 Prevents binding of virus to host cell Given IV Very expensive
What is HAART
Highly active antiretroviral therapy
2 nucleoside transcriptase inhibitors and either
- non nucleoside transcriptase inhibitor
Or
- protease inhibitor
Or
- integrase inhibitor
When are fusion inhibitors used
When the patient has been on HAART but have not responded to it (viral load has not been reduced)
When is HIV untransmissable
When the viral load has been undetectable for 6 months
97% of patients diagnosed with HIV are virally suppressed
What is molnupiravir
Pro drug
Ribonucleoside analogue increases the number of mutations in viral RNA
Prevents replication - lethal mutagenesis
Anti coronavirus medication (first oral)
50% reduction in hospital admission
30% reduction in severe complications (for unvaccinated patients)
For patients with at least 1 risk factor
What is remdesivir
Nucleotide prodrug of an adenosine analogue
An inhibitor of the viral RNA-dependent, RNA polymerase
IV
For hospitalised patients
What is HIV
A virus spread through certain body fluids that attacks the immune system
Life long condition
Highly stigmatised
Disproportionately affects vulnerable groups
Very treatable
Pathology of HIV
HIV infects lymphocytes with CD4 receptors
HIV binds to the CD4 receptor and enters cell
Uses enzymes to make copies of itself
CD4 cell destroyed in process
Decline in CD4 cells leads to immunosuppression
Describe the primary / acute infection of HIV
Within 7-21 days HIV becomes detectable in the blood stream- acute HIV symptoms due to extremely high levels of viraemia may occur within weeks to few months of infection
- main target CD4 T helper cells - can fall considerably at this time
- fever, rash, lymphadenopathy, meningitis, rarely opportunistic infections
- by 6 months CD4 recovers to a level as viral load falls to a set point
What are the stages of HIV infection
1) seroconversion: flu like illness shortly after infection. Viral load high, no anti HIV antibodies
2) asymptomatic: stable infection, no symptoms, lasts for years. Viral load low, anti HIV antibodies, stable CD4
3) symptomatic: signs of damaged immune system, infections, tiredness, weight loss, diarrhoea, cancers etc. any viral load, low CD4
What opportunistic infections are common at a CD4 count of >500
Persistent generalised lymphadenopathy
Candidal vaginitis
What opportunistic infections are common at a CD4 count of 200-500
Bacterial pneumonia
Pulmonary TB
Herpes zoster
Oral candidiasis
What opportunistic infections are common at a CD4 count of <200
Pneumocystis jiroveci pneumonia
Miliary / extrapulmonary TB
What opportunistic infections are common at a CD4 count of <100
Candida oesophagitis
Penicillinosis
Toxoplasmosis
Cryptococcosis
What opportunistic infections are common at a CD4 count of <50
Mycobacterium avium complex
Disseminated cytomegalovirus
Side effects of anti HIV medications
GI upset: nausea, diarrhoea Rashes and allergies Renal toxicity Liver toxicity Reduced bone mineral density Lipodystrophy and weight gain Increased cardiovascular risk / blood pressure / lipids / blood sugars Peripheral neuropathy
Drug interactions in anti HIV drugs
Very common with antiretrovirals Induction or inhibition of liver metabolism Gastric pH changing absorption Divalent cations reducing absorption Additive side effects Blocking renal excretion
Why is adherence so important in HIV patients
Need high levels of drugs in the blood all the time to stop virus multiplying
Taking tablets correctly all the time
- no missed doses
- no late doses
- follow food restrictions
Management of the HIV patient
Biannual visit once established on treatment and undetectable
Viral load, clinical chemistry, haematology, lipids, HbA1c, sexual health screening
Height, weight, BP, waist circumferece
Discuss adherence, mood, partners, bone risks, contraception, vaccination
Describe mother to baby transmission of HIV
Can occur:
- in utero (rare)
- at delivery (15-25%)
- breastfeeding (5-20%)
If no intervention at all and mother not on ART, rate of transmission is about 25% up to 45%
In the UK currently fewer than 5 babies per year are diagnosed with HIV
Prevention of HIV transmission during pregnancy
Pregnant women on an effective regimen should continue it
Newly diagnosed pregnant women start triple therapy asap with a resistance test
How is an infant with a HIV infected mother treated
Undetectable viral load x 2 in mother and on ART >10 weeks - 14 days of zidovudine monotherapy
- extend to 4 weeks if undetectable but other criteria is not filled
If mother >50 copies, unknown or adherence uncertain: start neonatal PEP within 4 hours with combination
Women in UK advised to formula feed
What is the Paul bunnell test
Tests for infectious mononucleosis which is caused by the Epstein barr virus (member of the herpes family)
What is the HIV p24 antigen
Present during the short period between HIV infection and seroconversion (when you have just been infected)
Thought of as not a very useful test as doesn’t give us much information as can usually tell the rough period of time of infection depending on the symptoms
How should you prepare for breaking bad news to a patient
Signpost / warn them you are about to break bad news Private room Allow time for questions Allow time for silence Patient doesn’t want it flowered Don’t give results with a friend or relative in the room Time Optimistic outlook
What are peer educators
People with HIV that have gone through training to offer support to people with newly diagnosed HIV
What does CD4 count indicate
T cells
What immunisations should someone with HIV be offered
Influenza each yea r
Hep B testing and immunisation as appropriate
Pneumococcal vaccination
Annual cervical smear recommended
Due to immune system becoming suppressed
Why would someone with HIV be given a bone mineral density scan using DXA
As HIV infection and some HIV medications increase the risk of osteoporosis
DXA is a dual energy X-ray used to measure bone mineral density with spectral imaging
What is atripla
600mg efavirenz
200mg emtrictiabine
300mg tenofovir disoproxil
What are the actions of the 3 drugs in atripla
Efavirenz: inhibits the activity of viral RNA directed DNA polymerase
Emtricitiabine: chain termination and ceases vira DNA synthesis
Tenofovir disoproxil fumarate: inhibits HIV-1 reverse transcriptase
Disadvantages of atripla
As it is 3 drugs in one it poses the issue of multiple drug reactions and side effects
Also adherence as if levels drop too low there is a risk of drug resistance
How to counsel a patient taking atripla
Take on an empty stomach, preferably at bedtime as helps to make the side effects less bothersome
Take the tablets at the same time every day
Can cause dizziness, trouble sleeping, drowsiness, unusual dreams and trouble concentrating
Avoid grapefruit juice as it can interfere with how the body deals with the drug
Side effects should start 1-2 days after starting the medication and usually go away within 2-4 weeks
Body fat may redistribute
Can cause bone problems and joint stiffness
Clinical monitoring during therapy with atripla
Creatinine clearance
Serum phosphate
After 2-4 weeks of treatment, after 3 months of treatment and every 3-6 months thereafter
How can atripla affect pregnancy
Can interfere with the contraceptive pill and stop it from being effective
Reinforce importance of condoms
What advice should you give to someone with HIV regarding pregnancy
Can conceive and have a normal pregnancy
Usual to use some form of self insemination to not infect partner
If viral load is low, expect a normal pregnnacy and uninflected baby
Not able to breastfeed
May have to have a ceserean
Baby will be put on 2 weeks of antivirals when born
Why should you avoid St. John’s wort with atripla
Can interact with efavirenz and decrease its concentration Severely
Moderately interacts with tenofovir by decreasing its exposure
