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. 

Capsaicin for osteoarthritis

Let’s begin with a patient case.  An elderly patient is being treated with acetaminophen 650 mg po q6hr prn osteoarthritis pain of the hands.  She takes all four doses on most days and does not feel this relieves her symptoms adequately.  She has multiple comorbidities and is looking for some therapy with improved efficacy.  She wants to know if Capzasin® over-the-counter would be a good choice.

Dosing colchicine in acute gouty arthritis

Let’s start with a patient case.  An elderly patient with multiple comorbidities is being treated in the hospital for heart failure when he develops an acute gouty attack.  His past medical history, among other things, includes CKD (Stage 4).  Should colchicine be used in this patient and if so, what dose would be indicated?

The American College of Rheumatology guidelines for the treatment of acute gout consider colchicine, NSAIDs, and corticosteroids all first line monotherapy (Evidence A) for moderate severity pain in 1-2 joints.  A combination of these is appropriate to consider in severe pain (Evidence C).  Since all have the same grade evidence for first line therapy, agent selection should be based on prior response, comorbidities, and patient preference while also considering each agent’s drug interactions. 

Vitamin K administration – Routes comparison

Let’s start with a patient case.  A patient is admitted to the hospital with a CHF exacerbation.  They are taking warfarin for atrial fibrillation and their coagulation panel reveals an INR of 8.  What are our options for administering vitamin K and some of the nuances for each route of administration?

Scenarios similar to this are common occurrences in the internal medicine setting as heart failure is an independent risk factor for overanticoagulation.  The decision whether or not to use vitamin K should be based on several factors which will not be addressed now.

Vitamin K can be administered by the oral, intravenous, intramuscular, or subcutaneous routes.  Vitamin K is a fat-soluble vitamin of which there are two types; one we find in green vegetables (and lots of other foods) and the other is synthesized by intestinal bacteria.  The vitamin K that we give for therapeutic use is the former, phytonadione.¹