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Research has found that antibiotics disrupt a person's normal gut microbiome (microbial community), especially because the antibiotics kill both bad (pathogenic) and beneficial bacteria. But what about other medicines? Do they also have an effect?

A recently published study that reviewed the research looked precisely at that topic and found that YES - other medicines (besides antibiotics) also have an effect on (disrupt) the gut microbiome. The different categories of drugs - proton pump inhibitors (PPIs), metformin, nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, statins and antipsychotics - all had different kinds of impacts on the gut microbiome.

The researchers also suggest that other types of commonly prescribed medicines now need to be examined for their impact on the intestinal (gut) microbiome, such as thyroid hormones, contraceptive drugs, and antihypertensive (high blood pressure) drugs. Excerpts from Dr. Paul Enck's article about the study at Gut Microbiota Research and Practice:

A systematic review explores the role of non-antibiotic prescription drugs in gut microbiota dysbiosis

Both diet and medications are among the strongest variables affecting the gut microbiome. When it comes to medications, although antibiotics have been repeatedly shown to affect the human gut microbiome, little is known regarding the impact of non-antibiotic prescription drugs on the gut microbiome.

review, led by Dr. Emmanuel Montassier from the MiHAR Lab at Institut de Recherche en Santé 2, Université de Nantes (Nantes, France), has concluded that some non-antibiotic prescription drugs have a notable impact on the gut microbiome to the same extent as antibiotics ...continue reading "Common Medicines That Disrupt the Normal Gut Microbiome"

Disturbing results from a study looking at data from over 1 million women enrolled in Medicaid before pregnancy from 2000 to 2007. More than four of five (82.5%) pregnant women were prescribed at least one medication, and 42.0% were prescribed a drug that is potentially harmful to the developing fetus.From Medscape:

Prescription Meds Common in Pregnancy; Maybe Too Common

Although most physicians acknowledge the complexity of prescribing drugs to pregnant women, they nonetheless prescribe them frequently. More than four of five (82.5%) pregnant women were prescribed at least one medication, and 42.0% were prescribed a drug that is potentially harmful to the developing fetus, researchers found in a large, population-based study.The study, which details the type and timing of medications prescribed to pregnant Medicaid patients, presents a disturbing pattern, according to Kristin Palmsten, ScD, from the University of California, San Diego, in La Jolla, and colleagues. 

Dr Palmsten and colleagues found that the most commonly dispensed medications are those used to treat infections. They also report that dispensing is more common for younger pregnant women and white women. The researchers examined data for women enrolled in Medicaid before pregnancy (n = 1,106,757), using 2000 to 2007 Medicaid Analytic eXtract data for prospectively collected medication information. The analysis included over-the-counter medications dispensed by a pharmacist, but excluded medications purchased over the counter directly or prescribed during hospitalizations.

The most commonly dispensed medications were nitrofurantoin (21.6%), metronidazole (19.4%), amoxicillin (18.0%), azithromycin (19.9%), and promethazine (13.5%). Other frequently dispensed medications include promethazine cephalexin and codeine with acetaminophen.....The investigators also note that nine of the 20 most commonly dispensed medications are rated as having limited to fair data quality and quantity to inform human teratogenic risk assessments by the Teratogen Information System.

Dr Palmsten and colleagues also found that 42.0% of pregnant women filled a prescription for a former US Food and Drug Administration (FDA) category D or X drug during pregnancy. Category D medications are associated with evidence of human fetal risk based on adverse reaction data. The top five most commonly prescribed category D medications were codeine (11.9%), hydrocodone (10.2%), ibuprofen (4.9%), sulfamethoxazole (4.0%), and hydrocortisone (4.0%). The authors note that some of those agents are considered category B or C drugs, depending on the circumstances of use.

Class X medications have been tested in animals or humans and found to cause fetal abnormalities. The five most commonly prescribed category X drugs were hormonal contraceptives (4.9%), temazepam (0.11%), atorvastatin (0.07%), simvastatin (0.04%), and warfarin (0.04%).

Moreover, the researchers note that many of the most commonly dispensed medications have limited or low-quality data available regarding safety during pregnancy. “Lack of unambiguous safety information may lead to the use of medications with potential to cause adverse pregnancy outcomes, whereas beneficial medications may be avoided,” they write. Many opioids are category N, meaning the FDA has not classified the drug. 

Although the solution to the complex problem of drug use by pregnant women is not clear, the FDA has made a change that is designed to better inform healthcare providers and patients about the risks of drugs. As of June 30, 2015, the FDA has changed the way it labels human prescription medications and biologic preparations for use in pregnancy and lactation. The new labels will include a summary of the risks of the drug during pregnancy.