Antibiotic exposure has long-lasting effects
Because premature infants are vulnerable to infection, most receive antibiotics frequently and often for long periods. Although antibiotic therapy can be lifesaving for these infants, new evidence reveals that it can also promote the development of drug-resistant bacteria in the intestine and disrupt development of normal, healthy intestinal microbial colonies. Additionally, these effects can persist for years.
Researchers analyzed 437 fecal samples collected from 58 infants aged from birth to 21 months. Forty-one infants were born around 2½ months premature; the remainder were born at full term. All the premature infants had been treated with antibiotics in the neonatal ICU. None of the full-term infants had received antibiotics. Among their findings:
- Premature infants who had been heavily treated with antibiotics carried significantly more drug-resistant bacteria in their gut microbiomes at 21 months than those who had received just one course of antibiotics or full-term infants who had not received antibiotics.
- Based on cultures of fecal samples taken 8 to 10 months apart, the drug-resistant strains present in older infants were the same ones that had established themselves earlier.
- All of the infants developed diverse microbiomes by age 21 months, but premature infants who had been heavily treated with antibiotics developed diverse microbiomes more slowly than lightly treated and full-term infants. In addition, heavily treated premature infants had fewer healthy groups of bacteria such as Bifidobacteriaceae, and more unhealthy types such as Proteobacteria.
Study coauthor Barbara Warner, MD, says that these findings have led her and her colleagues to modify their prescribing practices. “We're no longer saying, ‘Let's just start them on antibiotics because it's better to be safe than sorry,’” she says. “Now we know there's a risk of selecting for organisms that can persist and create health risks later in childhood and in life. So we're being much more judicious about initiating antibiotic use, and when we do start babies on antibiotics, we take them off as soon as the bacteria are cleared.”
Sources: Gasparrini AJ, Wang B, Sun X, et al. Persistent metagenomic signatures of early-life hospitalization and antibiotic treatment in the infant gut microbiota and resistome. Nat Microbiol. [e-pub ahead of print Sep. 9, 2019]. Washington University School of Medicine. Use of antibiotics in preemies has lasting, potentially harmful effects. News release. September 9, 2019.
Adjunctive treatment to manage “off” episodes
Classified as an adenosine receptor antagonist, Nourianz (istradefylline) oral tablets have been approved as an adjunctive treatment for use with levodopa/carbidopa in adults with Parkinson disease (PD) experiencing “off” episodes. In PD, off episodes occur when a patient's medication has become less effective, causing an increase in PD signs and symptoms such as tremor and difficulty walking.
The effectiveness of Nourianz was shown in four 12-week placebo-controlled clinical studies that included 1,143 participants being treated with levodopa/carbidopa, the standard therapy for PD. In all four studies, patients treated with Nourianz experienced a statistically significant decrease in daily “off” time compared with patients receiving a placebo. The most common adverse reactions were dyskinesia, dizziness, constipation, nausea, hallucinations, and insomnia.
Monitor patients taking the new drug for dyskinesia or exacerbation of existing dyskinesia. The dosage should be reduced or the drug stopped if the patient experiences hallucinations, psychotic behavior, or impulsive/compulsive behavior. Warn women of childbearing potential that the drug may cause fetal harm and advise them to use contraception during treatment.
Source: US Food and Drug Administration. FDA approves new add-on drug to treat off episodes in adults with Parkinson's disease. News release. August 27, 2019.
Updated guidelines for patients with MS
The American Academy of Neurology has issued an update of its 2002 vaccination guidelines for patients with multiple sclerosis (MS). Recommendations for clinicians include the following:
- Discuss the evidence regarding immunizations in MS with patients and explore patients' opinions, preferences, and questions.
- Recommend that patients with MS follow all local vaccine standards unless specific contraindications are present and weigh local vaccine-preventable disease risks when counseling patients.
- Recommend that patients receive the influenza vaccination annually.
- Counsel patients about infection risks associated with specific immunosuppressive/immunomodulating (ISIM) medications and treatment-specific vaccination guidance according to the prescribing information (PI). Patients with MS should be vaccinated as needed 4 to 6 weeks before initiating ISIM therapy.
- Screen patients for infections according to the PI before initiating ISIM medications and treat patients testing positive for latent infections.
- Recommend against using live-attenuated vaccines in patients with MS receiving ISIM therapies.
- Delay vaccination in patients with MS who are experiencing a relapse.
Source: Farez MF, Correale J, Armstrong MJ, et al. Practice guideline update summary: vaccine-preventable infections and immunization in multiple sclerosis: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology. Neurology. 2019;93(13):584-594.
High doses help certain patients with heart failure
Patients with acute decompensated heart failure who do not respond to loop diuretics such as furosemide may benefit from high doses of the potassium-sparing diuretic spironolactone. In a pilot study of 19 recently hospitalized patients with acute heart failure exacerbations, those who did not respond to standard therapy were given high-dose spironolactone and monitored for urine output and breathing. The usual dose of spironolactone for initiating treatment of heart failure is 25 mg/day. For this study, patients received 100 mg and, at some administrations, even 200 mg. “Most of them had a dramatic increase in their urine output and significant improvement in their shortness of breath,” said lead investigator Shweta Bansal, MD. “We think some patients could avoid needing dialysis if treated in this manner.”
Many patients with heart failure become resistant to loop diuretics, largely because high aldosterone levels stimulate the kidneys to excrete excess potassium and retain sodium. Spironolactone inhibits the action of aldosterone. Bansal and colleagues found that in higher doses, spironolactone safely and effectively relieved fluid overload in this small group of patients who failed to respond to loop diuretics.
Sources: Bansal S, Munoz K, Brune S, Bailey S, Prasad A, Velagapudi C. High-dose spironolactone when patients with acute decompensated heart failure are resistant to loop diuretics: a pilot study. Ann Intern Med. [e-pub ahead of print July 16, 2019]. University of Texas Health Science Center at San Antonio. New treatment option shown for heart failure fluid overload. News release. August 2, 2019.