Dabigatran with mechanical heart valves?

This week, the RE-ALIGN study was published in the New England Journal of Medicine, examining the use of dabigatran in patients undergoing a mechanical valve replacement or who underwent one at least three months earlier.  This study was a dose-finding study for dabigatran primarily looking at plasma trough concentrations in patients receiving 150-300 mg po bid depending on renal function (Yes, higher than doses used for atrial fibrillation).  The pharmacokinetic model used in the RE-LY study (the >18,000 patient study resulting in approval of dabigatran) was used to target certain trough concentrations and dabigatran titration was performed at prespecified intervals. 

Egg allergy and the 2013 Influenza vaccine

Let’s start with a patient case.  A 55 year old female patient is seen in clinic that has recently been diagnosed with COPD.  After suffering from influenza last year, she is now seeking the influenza vaccine.  Upon further questioning, the patient confirms she is allergic to eggs.  When she eats eggs, she develops hives but no other symptoms.  What can we tell her?

Foreign medication brand names

Let’s start with a patient case.  An elderly patient has recently arrived from Italy and you are performing the medication reconciliation from their home medication list.  Their medication list includes Flomax which may frequently be continued without hesitation.  In this example, however, Flomax is NOT the brand name for tamsulosin in Italy but rather the identical name for a different medication. 

Interpreting serum phenytoin concentrations

Let’s start with a patient case.  Patient is an 80 year old female hospitalized for pneumonia with sepsis who during this admission experienced a seizure likely secondary to imipenem/cilastatin.  She has since been on phenytoin for one week and is currently extremely confused, pulling out IV lines, and striking out at the staff.  Serum total phenytoin concentration = 16.4 mg/L.  Her SCr = 2.3 (acutely elevated) and albumin = 1.8 g/dL.  At first glance this phenytoin concentration appears therapeutic (10-20 mg/L).  What is the issue with interpreting this lab?

Tips for prescribing insulin therapy and diabetes supplies

There are many different insulin preparations and supplies available in order to create individualized regimens for patients.  Here are some tips and a checklist to help avoid getting future calls from pharmacies.

Interaction between linezolid (Zyvox®) and SSRIs

Linezolid is an oxazolidinone antibiotic (see more about its mechanism here) that is active against many gram-positive organisms including those that are resistant to multiple other agents such as methicillin-resistant staphylococci, penicillin-resistant streptococci, and vancomycin-resistant enterococci.  Linezolid is also a weak, reversible, inhibitor of monoamine oxidase (MAO), predominantly MAO-A, which is responsible for the metabolism of neurotransmitters such as serotonin, in the brain.  This effect has led to an increased risk of serotonin syndrome in patients taking other medications that increase serotonergic tone.  SSRIs fall in this category as they increase synaptic serotonin concentrations by preventing transport into the presynaptic neuron.  They are commonly prescribed for numerous psychiatric conditions. Due to the high prevalence of both depressive disorders and nosocomial infections in patients with chronic medical illnesses, this medication combination may be encountered in the hospital setting.  Though case reports are few, deaths have been reported due to serotonin syndrome and a Food and Drug Administration Safety Alert was issued in 2011 specifically warning about the linezolid-SSRI interaction.