Prevention of postherpetic neuralgia

An elderly patient is admitted to the internal medicine service with a diagnosis of herpes zoster infection in the typical dermatomal distribution.  The patient’s rash is currently not very painful (2/10) but she is concerned about long-lasting pain as her friend had pain from zoster that lasted for months.  What can we use to prevent the development of postherpetic neuralgia?

Postherpetic neuralgia is a common complication of herpes zoster infection and can be challenging to treat.  Drugs approved by the FDA to treat postherpetic neuralgia include pregabalin (Lyrica), gabapentin (Neurontin), and capsaicin patch (high-concentration patch - Qutenza).  Other medications that have been shown in randomized controlled trials to also reduce pain from postherpetic neuralgia include topical lidocaine, tricyclic antidepressants (eg. nortriptyline), opioids, and tramadol¹. 

No medication has been approved for the prevention of postherpetic neuralgia but here is the data on several agents that have been studied:

Is levalbuterol (Xopenex) more effective than albuterol?

The choice between levalbuterol and albuterol continues to be an area of contention for outpatients, in the emergency department, and those admitted into the hospital. Here is a brief explanation of the difference between the two products.

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.