HIV/AIDS Discussions and Pearls

Standard

Topics reviewed today:

Which medications to start and how to pick one from the other?

Nucleoside/Nucleotide RTIs: Abacavir (300 mg po BID or 600 mg po once daily), Didanosine, Emtricitabine (200 mg po once a day), Lamivudine (150 mg po BID or 300 mg po once daily), Stavudine, Tenofovir (300 mg once daily), Zidovudine

Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs)

Efavirenz (Dose: 600 mg daily), Etravirine, Nevirapine, Rilpivirine

Multi-class combination drugs: Efavirenz/Emtricitabine/tenofovir (600/200/300 mg tablet)

Protease Inhibitors: The 3 main ones that are used:
Darunavir 600 mg + 100 mg ritonavir BID or 800/100 mg QD for naive subjects
Atazanavir 400 mg QD or 300 mg with 100 mg ritonavir QD
Lopinavir/ritonavir (Kaletra) 400/100 mg BID or 800/200 mg QD (has good CNS penetration)
Kaletra + Phenytoin drug interaction: Usually phenytoin is switched to Levetriacetam (normal dose: 500 mg BID or 1000mg BID) . If not possible, frequency of Kaletra usually has to be increased from 2 tabs BID to 3 tabs BID due to enzyme induction effect of phenytoin and monitor using therapeutic drug monitoring to adjust the dose of phenytoin.

Picking between Truvada and Kivexa
Tenofovir: can lead to renal failure, osteoporosis (Choose based on renal function and bone mass density)
Some evidence that it is more effective if viral load is high
Tenofovir and Lamivudine (brand name Heptovir): Also works against Hepatitis B, patient could be HIV -ve and still be on Tenofovir

Cryptosporidosis: protozoa infects small bowel mucosa, immunosuppressed persons, the large bowel and extra-intestinal sites. Person-to-person transmission is common, especially among MSM. Most commonly presents with acute or subacute onset of profuse, nonbloody, watery diarrhea, accompanied often by nausea, vomiting and lower abdominal cramping.
Interesting fact: HIV-infected persons should avoid eating raw oysters because cryptosporidial oocysts can survive in oysters taken from certain commercial oyster beds.

Abacavir: Check for HLAB5701 hypersensitivity
Efavirenz: CNS side effects

Risk factors for PCP: CD4% <14%, previous episode of PCP, oral thrush, recurrent bacterial pneumonia, unintentional weight loss, higher plasma HIV RNA
Treatment dose for Septra: 1 DS tab PO TID or TMP-SMX (15-20 mg TMP and 75-100 SMX)/kg/day IV administered q6h or q8h
duration of treatment: 21 days
duration of primary prophylaxis: continue for adult and adolescent patients whose CD4+ count has increased from 200 cells/microL for >3 months as a result of ART. for secondary prophylaxis it can extend up to 6 months

Make sure you provide seamless care to your patient
Once treatment is finished, they should go home on a prescription for prophylaxis for Septra (1 DS tab daily or 1 SS tab daily) or 1 DS tab 3 times/week

An Immune reconstitution syndrome (IRIS) has been associated with initiation of ART in the presence of underlying OIs.
IRIS is characterized by fever and worsening of OI manifestations in the initial weeks after ART. An ART associated rapid-onset immune reconstitution against the OI pathogen is thought to be the mechanism of IRIS.
Three main OIs: PCP, MAC and cytomegalovirus retinitis

Therapy for cryptococcal meningitis: amphotericin B 0.7 mg per kg per day IV for a minimum of 2 weeks with or without flucytosine 100 mg per kg per day in 4 divided doses followed by fluconazole 400 mg per day for 8 weeks or until CSF cultures are negative

Toxoplasmosis gondii Encephalitis: Seroprevalence varies
Greatest risk among patients with CD4+ count less than 50 cells per microliter.
Primary infection occurs after eating undercooked meat containing tissue cysts or ingestion of oocytes that have been shed in cat feces and have sporulated in the environment. No transmission of the organism occurs by person-to-person contact.

Most common clinical presentation: headache, confusion, motor weakness and fever
Physical examination might show neurological abnormalities. If there is no treatment it can progress to seizures, stupor and coma. CT scan or MRI of the brain will typically show multiple contrast-enhance lesions often with associated with edema but can manifest as single lesions as well.

About rajwantminhas

I just finished my pharmacy degree at UBC. I am excited to be part of Lower Mainland Pharmacy Services. My goal is to get exposed to different kinds of disease states, medications and become better at applying my knowledge. Patient interaction is another aspect that I am going to strive to get better at. I am looking forward to this intense year and learning tonnes!

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