Aspirin for primary prevention of cardiovascular disease and predicting risk of first cardiovascular event

The benefit of aspirin in reducing cardiovascular (CV) events or mortality in those patients with known CV disease (secondary prevention) is well established.  However, the benefit of aspirin in those without CV disease (primary prevention) is less clear.  Various organizations have differing opinions and recommendations regarding who, if anyone, should receive aspirin in this capacity, and their recommendations are summarized further below.  To go straight to the current recommendations, skip down to 'Current Recommendations'.

Changes to FDA Pregnancy and Lactation Labeling

On December 3, 2014, the FDA issued a new rule revising the current regulations pertaining to the pregnancy, labor and delivery, and nursing mother sections of the prescribing information for prescription drugs and biologic products. Initiation of this amendment was prompted by the FDA’s goal to provide women and their healthcare providers with sufficient information when deciding which medications to prescribe in pregnant and breastfeeding patients.

^{Why the change?}

Recent data indicate that about 90% of pregnant women take at least one medication and 70% take one or more prescription drugs, potentially putting the fetus at high risk for drug-induced developmental abnormalities. Many pregnant women may also be on medications to control chronic disease states such as hypertension or to manage acute conditions developed during pregnancy such as gestational diabetes.  It is also necessary to consider that about half of all pregnancies are unexpected, leading to unintended drug exposure.

Heparin-induced hyperkalemia

Heparin and low molecular weight heparins (LMWH) are some of the many medications that have been identified to cause hyperkalemia.  When looking for more information about this in the prescribing information, Lexicomp, and Micromedex, there is a paucity of information.  

The prescribing information does not mention potassium at all, merely stating that suppression of aldosterone synthesis has been reported, whereas the other sources give rates from <1% to 8%.  The following will discuss the typical time course and extent of changes in potassium identified in some studies, the proposed mechanism for these effects, and risk factors.

Use of sodium polystyrene sulfonate for hyperkalemia

Let's start with a patient case.  A 58 year old male is sent to the hospital from his PMD for hyperkalemia.  He has a past medical history of diabetes mellitus type 2, hypertension, osteoarthritis, and obesity for which he is taking sitagliptin 100 mg daily, lisinopril 20 mg daily, atorvastatin 80 mg daily, and aspirin 81 mg daily.  Pertinent findings on arrival to the emergency department are SCr = 1.2 mg/dL (at his baseline), K+ = 5.9 mEq/L (previously 4.2), blood pressure = 152/96 mm Hg, Hb A1c = 10.8%, and a normal EKG.  Upon further questioning about his medication and supplement use, he admits to occasional ibuprofen and oxycodone use this past month for his osteoarthritis and is newly using Morton's Salt Substitute (as he's trying to avoid salt because of his uncontrolled hypertension).  What is the role of sodium polystyrene sulfonate (SPS) in this situation?

Risk of peripheral neuropathy with fluoroquinolones

Last year, the FDA issued a drug safety communication, warning about the risk of nerve damage from fluoroquinolone antibiotics.  You can read last year's post about the warning and other information on fluoroquinolones here: Serious peripheral neuropathy and fluoroquinolones.  

The questionable role of digoxin in atrial fibrillation

Let's start with a patient case.  An elderly patient is admitted to the hospital with complaints of intermittent shortness of breath and a fluttering feeling in his chest.  He has a past medical history of hypertension, atrial fibrillation, and heart failure (EF 6 months ago = 30%).  He is currently taking ramipril 10 mg daily, metoprolol succinate 50 mg daily, and warfarin 6 mg M/W/F and 3 mg the rest of the week.  Other findings include a BP of 106/56 mm Hg, a creatinine clearnace of 40 mL/minute, an INR of 1.28, and atrial fibrillation with a heart rate in the 80s but a rapid ventricular response intermittently into the 120s bpm.  What should be recommended at this time to control this patient's atrial fibrillation and what is the role of digoxin, if any?