Navigation Links
2 drugs protect hearing better than 1
Date:2/23/2011

Whether on a battlefield, in a factory or at a rock concert, noise-induced hearing loss is one of the most common hazards people face.

Researchers at Washington University School of Medicine in St. Louis have identified a low-dose, two-drug cocktail that reduces hearing loss in mice when given before they are exposed to loud noise. The drugs, already FDA-approved for other conditions, also treat hearing loss after noise exposure.

While both drugs are known to protect hearing on their own, this is the first study to test the two in combination.

"We found they have synergy," says Jianxin Bao, PhD, research associate professor of otolaryngology at the School of Medicine. "Two drugs at lower dosages can block more signaling pathways than one alone, improving results while reducing side effects. We got the idea from cancer and HIV studies that use multiple drugs at lower dosages."

Bao presented the work Feb. 21 in Baltimore at a meeting of the Association for Research in Otolaryngology.

In earlier work, Bao's group found that anticonvulsant drugs for treating epilepsy helped protect hearing in mice after exposure to loud noise. And other groups had determined that glucocorticoids, anti-inflammatory drugs often used to treat allergies and asthma, were also protective.

The reasons these drugs reduce noise-induced hearing loss are not well understood. But anticonvulsants are known to block calcium channels in nerve cells, and Bao's group speculates that the drug helps protect neuronal connections between hair cells and auditory neurons.

For this work, Bao and colleagues chose two drugs from the anti-epilepsy family and two from the glucocorticoid family.

"We picked drugs that have fewer side effects and that can be chronically used," says Bao, also associate professor of audiology and communication sciences.

To test each drug's ability to prevent hearing loss, they gave various doses to mice two hours before exposing them to noise. To test treatment, they administered the drugs to different groups of mice 24 hours after noise exposure.

Three of the four drugs showed increasing protection with higher doses. And two of the drugs in combination, the anticonvulsant zonisamide and the glucocorticoid methylprednisolone, showed comparable hearing protection at much lower doses than when administered alone.

While the drugs do not prevent all hearing loss following sustained exposure to noise at 110 decibels, or about the sound of a chain saw, they can significantly reduce the loss by about 10 to 30 decibels.

In other words, a mouse with normal hearing might be able to hear a sound at 30 decibels. After exposure to loud noise, that mouse might only hear sounds that reach 50 decibels. But if that mouse were treated, it might be able to hear sounds at 40 decibels. In humans, protecting 5 or 10 decibels makes a difference in being able to hear everyday speech.

Bao says their next step is to test the drugs in animals that model human hearing more closely.


'/>"/>

Contact: Julia Evangelou Strait
straitj@wustl.edu
314-286-0141
Washington University School of Medicine
Source:Eurekalert

Related medicine news :

1. The private sale of drugs in public hospitals
2. Social Anxiety and Panic - Alternative Treatment to Drugs and Therapy
3. Adapting to clogged airways makes common pathogen resist powerful drugs
4. Diabetes Drugs Avandia, Actos Tied to Fractures in Women
5. Drugs That Shift Cells Energy Find New Purpose
6. FDA Tightens Controls on Anemia Drugs
7. FDA Issues Warning on Key Asthma Drugs
8. Two Tulsa Pharmacies Penalized for Missing Prescription Drugs
9. Tests to Measure Safety of Anti-Clotting Drugs of Limited Value
10. Notch-blocking drugs kill brain cancer stem cells, yet multiple therapies may be needed
11. Scans Might Monitor Success of Alzheimers Drugs
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/28/2017)... ... 2017 , ... Award-winning medical group Allied Anesthesia today announced ... chair for Orange County health care system CalOptima Friday. CalOptima announced its election ... Mark Refowitz’s term, which runs through June 30 of this year, until another ...
(Date:3/28/2017)... ... March 28, 2017 , ... In its ... Success website has recently developed and published an informational resource that addresses frequently ... based on common inquiries the site’s team of third party administrator (TPA) contributors ...
(Date:3/28/2017)... CA (PRWEB) , ... March 28, 2017 , ... ... Carson Liu of SkyLex Advanced Surgical, Inc. is thrilled to offer the recently ... balloon procedure, and this procedure adds to SkyLex Advanced Surgical’s already comprehensive ...
(Date:3/28/2017)... ... , ... Oily skin is a common and unwelcomed occurrence in people of all ages, genders ... offer to the discussion of dealing with excess skin oil. “Oily skin is a challenge ... that can help remove the oily shine while keeping the skin fresh and clean,” says ...
(Date:3/27/2017)... ... 27, 2017 , ... New patients who have sleep apnea in ... or without a referral. Sleep apnea is often left untreated because patients are not ... and chronic snoring. , Dr. Braasch seeks to raise awareness of sleep apnea ...
Breaking Medicine News(10 mins):
(Date:3/27/2017)... , March 27, 2017  Sanderling Ventures, portfolio ... Ethicon, a division of Johnson & Johnson. Torax manufactures ... the treatment of gastro-esophageal reflux disease (GERD). The ... (MSA) technology and the procedure is currently available ... Torax Medical was founded by Sanderling Ventures, ...
(Date:3/27/2017)... FinancialBuzz.com News Commentary  ... According to a new report by Arcview Market Research, the ... 34 percent to $6.7 billion and can be expected to grow at ... five years, from $6.7 billion in 2016, to $22.6 billion in 2021. ... to purchase cannabis without a doctor,s recommendation. Voters in California ...
(Date:3/27/2017)... 2017 The staggering cost of cancer treatment ... access to the latest treatment options against cancer. Even ... patients have inadequate or no health insurance and are ... Access to modern cancer treatment is almost non-existent for ... The mission statements of pharmaceutical and biotech companies ...
Breaking Medicine Technology: