Niacin for dyslipidemia

Niacin is one of our options for managing cholesterol in patients with dyslipidemia.  The benefits of high doses of niacin are well established in reducing triglycerides by 20-50%, reducing LDL by 10-25%, and increasing HDL by 10-30%.  What is not well established, however, are the clinically beneficial endpoints of niacin. 

Use of dexamethasone for vasogenic edema

Vasogenic edema is a result of a disruption of the blood brain barrier that is frequently related to tumors.  The edema can lead to increased intracranial pressure in addition to tissue shifts and brain displacement.  Injury can occur not only from this mechanical shift but also from decreased perfusion that is associated with elevated intracranial pressure.

Dexamethasone is a potent, long-acting glucocorticoid which has no inherent mineralocorticoid activity.  Glucocorticoids have a number of mechanisms for how they reduce inflammation in the body including reduction in lymphocytes, monocytes, basophils, and eosinophils (neutrophils decrease at the site of inflammation but increase in the blood); suppression of the arachadonic acid cascade by inhibiting phospholipase A2 which reduces prostaglandins and leukotrienes; inhibition of other antigen presenting cells; vasoconstriction and decreased capillary permeability; and at large doses, reduced production of antibodies.

Does enteric coating aspirin change efficacy or adverse effects?

Bleeding risk with anticoagulant and antiplatelet medications is something that we struggle with on a regular basis.  Should we fully anticoagulate a patient with atrial fibrillation who is falling?  Should we continue the aspirin and clopidogrel even though it’s X number of months since their stents? 

New drug of abuse comes to America – Enter krokodil

Reports developed in the media last month identifying suspected cases of ‘krokodil’ use in Utah, Arizona, and Illinois.  While the drug’s presence has not officially been confirmed there is a significant health concern when considering this new drug’s properties and what the results of its use are.

Azithromycin and cardiovascular risk

Since 2012, the FDA has made two statements regarding the safety of azithromycin related to cardiovascular risk.  These warnings were largely in response to an observational cohort study that found a small absolute increase in cardiovascular deaths in patients receiving azithromycin versus those receiving amoxicillin or no antibiotic in a Tennessee Medicaid population¹.  This excess risk varied based on patients’ baseline cardiovascular risk and was found to be highest in the highest decile of cardiovascular risk.  While a warning from the FDA does seem concerning, it is important to examine some of the details of the data.

• Of the 347,795 azithromycin prescriptions in the study cohort, there were 29 cardiovascular deaths (absolute risk = 0.008%)
• Of the 1,391,180 matched controls, there were 41 cardiovascular deaths (absolute risk = 0.003%)
• These above cardiovascular deaths occurred during the five day treatment course, whereas the analysis that also included the following five days had no difference in death from any cause
• 4,082 prescriptions would have to be used in patients at the highest cardiovascular risk decile to cause one additional cardiovascular death

Serious peripheral neuropathy and fluoroquinolones

This week’s pharmacy pearl describes a recent alert from the FDA that you might have heard about regarding fluoroquinolones.  Fluoroquinolones are a diverse group of antibiotics used to treat various types of infections including pulmonary, genitourinary, skin, gastrointestinal, and bone infections. 

A recent warning from the FDA announced the potential for all systemic (IV or po) fluoroquinolones to cause serious peripheral neuropathy.  While peripheral neuropathy has been a known side effect of fluoroquinolones for nearly a decade, the FDA felt that the nature of this reaction was not sufficiently described.   They state that a large review has shown a continued association between fluoroquinolones and “disabling” peripheral neuropathy.  Peripheral neuropathy may occur rapidly, within a few days, and has persisted for longer than a year, even when the medication was discontinued.  No risk factors were identified, including age and duration of therapy.  The specific incidence or prevalence was not listed and it is likely underreported since the review was done through the FDA’s Adverse Events Reporting System.  Events occurred with all systemic drugs in this class.

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. 

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