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?

Role for polyethylene glycol in treating hepatic encephalopathy?

Hepatic encephalopathy is a frequent and debilitating complication of liver disease.  The mainstay of treatment, lactulose, has been used since the 1960s, even without a strong evidence-base for efficacy.  Currently, in the AASLD guidelines for hepatic encephalopathy, updated in 2014, lactulose is recommended as first line therapy for the treatment of episodic overt hepatic encephalopathy (Grade II-1,B,1 which means controlled trials without randomization, moderate evidence strength, strong recommendation)1.  It's notable that there is a cost appeal of lactulose compared to alternative or add-on therapies such as rifaximin and this is considered in their recommendation.