Low blood pressure drug midodrine may be recalled in US

Midodrine, widely use drug treat low blood pressure or hypotension, may be recalled from the US market due to some concerns over the drug’s safety.

Currently, midodrine is marked in US by Shire Plc under the brand name ProAmatine. Generic versions of midodrine is also being sold by several companies including Impax Laboratories, Mylan Pharmaceuticals Inc and Novartis unit Sandoz.

The withdrawal of midodrine is proposed by US FDA experts as Shire Plc because the company failed to conduct post-approval studies on the hypotension drug.

Midodrine was approved in 1996 by US FDA to treat orthostatic hypotension, a type of low blood pressure.

According to US FDA, as many as 100,000 U.S. patients used brand or generic forms of the drug in 2009.

What is low blood pressure?

Low blood pressure (hypotension), where blood pressure is so low. Low pressure causes symptoms or signs due to the low flow of blood through the arteries and veins. When the flow of blood is too low to deliver enough oxygen and nutrients to vital organs such as the brain, heart, and kidney, the organs do not function normally and may be permanently damaged.

Low blood pressure is defined primarily by signs and symptoms of low blood flow and not by a specific blood pressure number. People may have a blood pressure of 90/50 with no symptoms of low blood pressure and therefore do not have low blood pressure.

But people who normally have high blood pressure may develop symptoms of low blood pressure if their blood pressure drops to 100/60.

Blood pressure is the force exerted by circulating blood on the walls of blood vessels. Blood pressure is generated by the heart pumping blood into the arteries.

An individual’s blood pressure is expressed as systolic/diastolic blood pressure. The normal renge is 120/80.The top number or systolic blood pressure (the top number) represents the pressure in the arteries as the muscle of the heart contracts and pumps blood into them. The diastolic blood pressure (the bottom number) represents the pressure in the arteries as the muscle of the heart relaxes after it contracts. Blood pressure always is higher when the heart is pumping (squeezing) than when it is relaxing.

Systolic blood pressure for most healthy adults falls between 90 and 120 millimeters of mercury (mm Hg). Normal diastolic blood pressure falls between 60 and 80 mm Hg. Current guidelines define normal blood pressure as lower than 120/80. Blood pressures over 130/80 are considered high.