Thursday, December 15, 2011

Second Week at the AIDS Clinic

Second week is almost over - it's been interesting.  This week he started his inpatient rounds at the hospital, so we've been going to the hospital in the mornings and rounding on whichever of his patients happen to be hospitalized or cases that require his consultation.  Had a case of mesenteric venous thrombosis, which apparently is pretty uncommon so they have been doing a full coagulation disorder work up - protein C, protein S, antithrombin III, antiphospholipid antibodies, the works.  More and more data have been coming out suggesting that HIV infection in itself produces a hypercoagulable state, and thus people are more likely to suffer a thrombosis or a stroke simply because they are HIV positive.  It is not precisely known why, but they are looking into it.  

There have been a few altered mental status patients as well, and one who has a recurrence of toxoplasmosis in addition to esophageal candidiasis and other things.  Been seeing lots of patients with lipodystrophy, or abnormal lipid deposition due to the HIV medications.  A lot of the medications cause fat deposition on the abdomen and the neck, and sucks fat away from the arms, legs, buttocks, and cheeks, so they can end up with a very odd body habitus.  A lot of them come in for problems unrelated to the HIV, such as poorly controlled diabetes, or joint pain.  The doctor I am shadowing spends 45 minutes or more with most of his patients because he goes through a list of 20 issues, some of them pretty minor.  He is definitely very comprehensive - takes his time, makes sure to ask about every aspect of the patient's life.  Being a primary care physician for so many patients as well as a specialist looks quite challenging - especially since they don't have medical records so he still does a lot of writing up of charts and has to go to the hospital to sign for things.  

On Wednesday morning I got to attend HIV grand rounds at San Francisco General Hospital - the doctor I am shadowing as well as a UCSF HIV pathology researcher/lecturer and the Kaiser Permanente HIV management physician were on a panel to discuss some interesting cases and do some Q&A.  It was good that I had had a lot of discussions with the doctor about HIV before the panel, because otherwise some things would have been harder to follow.  At the end of this rotation I will definitely know all the combination therapies, as well as which drugs are NRTIs, NNRTIs, and PIs.  It's gotten easier already.  

Two things I have learned about on this rotation are HIV strain reversion to wild type, and protease inhibitor "boosting".  Because patients go on and off drug regimens when they gain and lose insurance, they can develop resistant strains of HIV - however, some of these mutations that develop decrease the fitness of the virus (similar to sickle cell increasing resistance to malaria but decreasing overall fitness/survival in humans).  Anyhow, while there are drugs exerting selection pressure, the mutants can survive and overpopulate the wild type, but when the drugs are discontinued the mutants die off and the wild type becomes the dominant strain.  Sometimes the mutant type is no longer replicating so genotype tests will not show any resistance patterns.  However, because HIV is a drug that integrates and hides in host cell DNA, those resistant mutants are usually still hiding somewhere in a cell in the body and can emerge again if you re-start therapy with the drug that selected for them in the first place.  This can make treatment a challenge.  As far as protease boosting, we were taught a list of 'protease inhibitors.'  One of the protease inhibitors is ritonavir, which I thought was like the other protease inhibitors, but turns out that it is not particularly effective at suppressing the virus, but acts to improve the effectiveness of the other protease inhibitors such as darunavir or fosamprenavir.  So that was useful to know - I was wondering why I kept seeing 3 drug regimens that had four drugs listed (including ritonavir, which they don't count as one of the 3 drugs).

Anyhow, one more day tomorrow - just hospital rounds in the morning - and then a 3 day weekend!

Wednesday, December 7, 2011

First Week at the AIDS clinic

This week I started shadowing an HIV physician at the AIDS Clinic in the city - the first day I tried driving and quickly discovered it would be a nightmare and is impossible to do for a decent price on a regular basis.  I figured out the BART schedule and the next day I came in that way - I have about a 15-20 minute brisk walk to the hospital, so that gives me a little exercise - I may start packing a change of shoes though in my backpack, don't exactly want to be walking several blocks in semi-heels or boots that are more fashionable than functional.  

As for the actual rotation - again pretty chill.  Most days I don't need to get there until pretty late in the day - 10-ish.  Some days even later - this Thursday I don't need to be there til 1:45pm.  We also get off relatively early.  And I get one day a week completely free, and Fridays he doesn't have patients in the afternoon.  The patients are mostly homosexual men with HIV - they are surprisingly compliant with their regimens - I haven't yet heard him give a lecture about how they need to be better about taking their medicines.

Yesterday I got to accompany him to a nearby hospital pharmacy where we met with a drug rep and my preceptor spoke about a new single dose multi-drug pharmaceutical that was FDA approved recently.  He says he looks at his main role as a health educator, and doesn't try to push one drug over others, that he doesn't speak for companies that wish him to be more heavy-handed in his talks.  At any rate, I got to learn a lot about Complera, and it's predecessor Atripla.  

Here's some of the medico-pharmacologic stuff that you may not be interested in but I will talk about nonetheless.  One of the major challenges with HIV treatment is that there are a ton of drugs, a lot of them have weird side effects, and a lot of the drugs have to be taken at various times of the day, making for a complicated regimen for patients.  Before Complera, there was only one single-dose multiple drug combination pill that could be used in patients with HIV.  Single day dosing is pretty rare in a lot of medications, and combination pills can be extremely useful.  The disadvantage with combination pills is that the dosages are fixed, so you cannot increase the level of drug A in combination ABC, you have to stick with the set dosages of A, B, and C.

Anyhow, a standard regimen for an HIV patient is two nucleoside reverse transcriptase inhibitor (NRTI)  class drugs, plus either a non-nucleoside reverse transcriptase inhibitor (NNRTI) class drug or a protease inhibitor (PI) class drug.  Atripla contained two NRTIs and one NNRTI (Efavirenz).  Efavirenz has a fair amount of side effects.  Anyhow, they came up with a new combination drug Complera, which is the same two NRTIs as in Atripla, but has Rilpivrine in place of Efavirenz - they are both NNRTIs.  Physicians also often add a protease inhibitor (plus a booster drug to increase it's effectiveness).  It was neat hearing about the differences between them, the restrictions.  We also got a free lunch, though apparently there's a new policy that pharmaceutical reps cannot provide catering to their events - another attempt to prevent there from being any "buttering up" to encourage use of the drugs.  I understand but if you are presenting during lunch time, it would be advantageous to provide a lunch...  

We also had a patient who decided he wanted to stop all his antibiotics that were treating him for Mycobacterium avium complex (a different species from Mycobacterium tuberculosis, which causes tuberculosis, and all species of Mycobacteria are notoriously hard to treat).  His reasoning: He has been getting magnetic therapy.  I immediately thought of the Penn and Teller episode about magnetic and other kind of hand-waving snake oil type new age medical treatments that masquerade as medical treatments but really just are, like the title of their show, bullshit.  I don't particularly object to gullible or desperate people trying alternative treatments, but I do object when these unproven, possibly dangerous, treatments are used in place of evidence-based medicine that WILL work!  Hopefully that guy won't have a recurrence of his infection, which may by this time be resistant to the antibiotics he was being treated with before...