Statins Can Save Your Eyes

May 10, 2013

By Medical Discovery News

Today, 2.7 million Americans over the age of 40 are suffering from an eye disease that slowly robs them of their sight. And about half of them don’t even know they have it, despite the fact that a comprehensive eye exam will easily detect it. While there is still no cure for glaucoma, a new study shows that statins, one of the most commonly used class of drugs, might actually prevent it.

Glaucoma usually occurs when the pressure of the fluid in the eye slowly increases, eventually damaging the optic nerve. The optic nerve is actually a bundle of nerves that carries information from the eye’s retina to the brain, where images are interpreted. The fluid in the eye, called the aqueous humor, circulates around inside the eye. This fluid provides nourishment to parts of the eye that do not have blood vessels and maintains the appropriate pressure inside the eye, both of which are keys to normal vision. A small amount of the fluid is produced every day while an equal amount flows out. With glaucoma, the fluid does not leave the eye as it should, gradually increasing the pressure on the eye as fluid accumulates.

A nationwide study by the University of Michigan School of Medicine found that statins like Lipitor and Zocor can lower the risk of developing glaucoma. The largest study ever done on this topic followed 300,000 people aged 60 and over who were diagnosed with hyperlipidemia, or high levels of unhealthy fats called lipids. In taking statins continuously for two years, the subjects reduced their risk of developing the most common kind of glaucoma by almost 10 percent.

The most common type of glaucoma, called primary open-angle glaucoma, is caused by not enough of the fluid draining. Other types of glaucoma can be caused by the iris blocking the eye’s fluid from draining, inheriting genes for the disease, injury to the eye, tumors, or even steroids. Treatment for glaucoma depends on the type of glaucoma, its severity, and its response to treatment. Medicated eye drops can either increase the drainage of the fluid or reduce its production. Several types of surgery and laser treatments can improve the fluid drainage. Medical marijuana can reduce pressure on the eye, but only for a short time and is not a recommended treatment. 

For the millions of the people already taking statins, the study revealed a surprising added benefit. Leaders of the study do not yet know why statins have this effect, but think it may be due to the drug increasing blood flow to the optic nerve and retinal nerve cells and pushing out extra fluid, alleviating pressure in the eye.

Annual eye exams are a good addition to a yearly physical, especially for those most at risk for glaucoma: blacks, Hispanics, seniors, those with diabetes, and those with a family history. The damage caused by glaucoma is irreversible, so prevention and early detection are currently the best way to combat the disease.

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Grapefruit Juice – A Dangerous Mix

March 22, 2013

By Medical Discovery News

Millions of Americans sit down every morning with a cup of coffee, milk, or juice and take their daily medications. The problem? Depending on what’s in that cup, they may be putting themselves at risk for serious side effects or even death.

It’s not the coffee or the milk – it’s the juice, specifically grapefruit juice. A recent study in the “Canadian Medical Association Journal” identified 85 drugs that interact with grapefruit juice, of which 43 can cause serious problems. Many of these drugs are commonly prescribed for important medical conditions: Lipitor for lowering cholesterol, Nifediac for lowering blood pressure, Xanax for treating depression, oxycodone for pain relief, and even Viagra. 

When drugs are taken orally, they move through the stomach to the small intestine, where the majority of absorption to the bloodstream occurs. Once in the bloodstream, the drug begins to take effect and start working.

Then, the body starts to inactivate and break down drugs, first in the intestine and continuing in the liver, in order to be removed from the body. A superfamily of enzymes called cytochrome P450 is responsible for this. An important member of this enzyme family is CYP3A4, which processes about half the drugs in use today, including acetaminophen, codeine, diazepam, and erythromycin.

However, in addition to grapefruits, Seville oranges, tangelos, limes, and pomelos can also disrupt this process. They all contain furanocoumarins, which reduce the amount of CYP3A4 in the intestine. Without enough of this enzyme to start inactivating and breaking down the drug, more of it enters the bloodstream instead.

Too much of a drug in circulation can be toxic, causing damage to the liver and kidneys, gastrointestinal tract bleeding, respiratory failure, bone marrow suppression, and even death. For example, levels of the blood pressure medication filodipine in the blood are five times higher when it is taken with grapefruit juice instead of water.

Ironically, while it can be toxic when taken with some drugs, grapefruit can dampen the effect of others. For example, it reduces the absorption of the allergy medication Allegra, making it less effective. This may be because it blocks the specific proteins that transport Allegra cross the membranes of the gastrointestinal tract.

The influence of a single glass of grapefruit juice on a drug’s metabolism can last for up to 24 hours. And if someone drinks grapefruit juice more than once a day, the effect is amplified. However, since reactions differ among individuals, some people don’t react at all. Those on prescription medications should ask their doctor or pharmacist how to properly take them. To see a list of the 85 medications that interact with grapefruit, visit http://www.medicaldiscoverynews.com.

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