Interpreting minimum inhibitory concentrations

Several previous discussions have dealt with the concept of the minimum inhibitory concentration (MIC) such as extended-infusion piperacillin/tazobactam (Zosyn) and vancomycin dosing in hemodialysis.  Though this concept was learned at some point, questions occasionally arise as to what these numbers represent and what to make of them when they show up on a culture and sensitivity result.  This post will discuss the MIC and hopefully address some common misconceptions.  For the take home points, skip down to the bullets at the end.

About becoming a clinical pharmacist

In this post we'll discuss some of the basic questions about clinical pharmacists including the steps in becoming a pharmacist, resident, and clinical pharmacist and what competencies a clinical pharmacist should have.  I'll also mention some statistics to give objectivity to the process.

4 T's - Determining the probability of HIT

An earlier post discussed how to bridge argatroban to warfarin in patients with HIT but didn't cover how to determine the likelihood of HIT when it is suspected.  This post will cover the 4 T's that are used to quantify this probability and guide clinical decision-making.

Risk of serotonin toxicity with procarbazine

A question recently came up regarding the risk of serotonin toxicity from a drug interaction between procarbazine and a number of different serotonergic agents.  When checking for an interaction between procarbazine and medications like sertraline, duloxetine, nortriptyline, and tramadol on resources such as Lexicomp and Micromedex, the interactions are listed inconsistently, from no interaction to contraindicated, with varying degrees of evidence, from theoretical to established.

Doxycycline food and OTC interactions

Since it's the time of year again when Lyme disease is a concern for patients in many parts of the United States, I thought it would be good to discuss one issue concerning doxycycline.  Doxycycline is a preferred oral agent for Lyme disease and many of its complications.  It is recommended for a variety of situations when Lyme disease is suspected or confirmed such as1:

• Single dose prophylaxis after tick bite
• Erythema migrans
• Cranial nerve palsy
• Carditis
• Lyme arthritis
• Acrodermatitis chronica atrophicans
• Co-infection with human granulocytic anaplasmosis

When ordering or verifying the typical adult dose of 100 mg orally twice daily, an alert may pop up for an interaction with several drugs including iron, calcium, magnesium, aluminum, or bismuth subsalicylate.  The proposed mechanism for this interaction is chelation in the gastrointestinal tract, compounded by the enterohepatic circulation of doxycycline.  Let's look at some of the data regarding these interactions.

Update on niacin - Results from the HPS2-THRIVE study

In a previous blog post, niacin for dyslipidemia, we discussed the concerns regarding niacin's lack of improvement of clinically meaningful endpoints in addition to some of its adverse effects and how to deal with them.  Recently, final results of the HPS2-THRIVE study have been published.  Here are a few highlights of the results of this study.