HIV and ID Observations

We do a post-graduate course each year called “ID in Primary Care,” and it’s a great way for us to find out what people in outpatient primary care practice are thinking about from the ID perspective.

I told the participants this year I’d post some of their most interesting questions on this site, with the hope that if we didn’t know the answer, perhaps some of you out there would.

Here’s a half-dozen from today:

1. Since we need to use trimethoprim-sulfa for MRSA now, should we stop using it for UTIs?
   A: The rate of MRSA-resistance to TMP-SMX among community isolates in the USA remains fairly low. It seems unlikely that the short course we use for UTIs would change this much. In my experience, most of the patients I’ve cared for who have a TMP-SMX-resistant MRSA have been receiving it chronically, usually for prevention of PCP.
2. Are there established risk factors for tendonitis on quinolones?
   A:  Older age, obesity, gout, and receipt of corticosteroids are reported risk factors for tendon disorders in this study; age and steroid use also came up in this one. Anecdotally, I’ve seen it in people younger than 60 and not on steroids, so clearly it can happen to anyone, risk factors aside.
3. Should we use clindamycin empirically for treatment of MRSA?
   A:  Aside from the obvious recommendation for I and D as critical to treatment of extensive soft tissue infection due to MRSA, we really have very little data on the optimal outpatient antibiotic to use for MRSA — or whether they are needed at all.  That said, rates of resistance to clindamycin (either complete resistance or D-test positive resistance) are higher than to TMP-SMX or doxycycline. So personally I prefer not using clindamycin unless necessary, a view further reinforced by the elevated C diff risk with that drug.
4. Should the zoster vaccine be given to someone who’s already had zoster?
   A:  The short answer is yes — based on both guidelines and the fact that these are the most motivated patients to get the vaccine. But we should remember that the pivotal clinical trial establishing the efficacy of the vaccine excluded people with prior zoster, so it’s not known if it adds additional protection to the “auto-immunization” of an actual bout of shingles.
5. Any commonly used drugs for UTIs interfere with oral contraceptives?
   A: Nope. But watch out for rifampin, which interacts with practically everything under the sun.
6. If someone has been coughing for more than a year (!), with no fevers and a negative chest X-ray, should they still be worked up for pertussis?
   A: Though pertussis in adults is famous for causing prolonged cough, it’s hard to imagine that after 12 months making this diagnosis — even if you could — would 1) lead to a treatment that has any effect or, 2) prompt an intervention that reduces contagiousness. So I’ll go out on a limb and say forget about it.

 Another batch coming soon.