Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.
Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
They also have been found to prevent further heart attacks and death after a heart attack. Other uses include the treatment of
(restlessness or inability to sit still), and anxiety.
Some beta blockers reduce the production of aqueous humor in the
eye and therefore are used for reducing pressure in the eye caused by glaucoma.
Are there any differences among beta blockers?
Beta blockers differ in the type of beta receptors they block and, therefore,
Non-selective beta blockers, for example,
propranolol (Inderal), block
β1 and β2 receptors and, therefore, affect the heart, blood vessels, and air
Selective beta blockers, for example,
metoprolol (Lopressor, Toprol XL)
primarily block β1 receptors and, therefore, mostly affect the heart and do not
affect air passages.
Some beta blockers, for example, pindolol (Visken) have intrinsic
sympathomimetic activity (ISA), which means they mimic the effects of
epinephrine and norepinephrine and can cause an increase in blood pressure and
heart rate. Beta blockers with ISA have smaller effects on heart rate than
agents that do not have ISA.
(Normodyne, Trandate) and carvedilol
(Coreg) block beta and alpha-1 receptors.
Blocking alpha receptors adds to the blood vessel dilating effect of
labetalol and carvedilol.
With which drugs do beta blockers interact?
Combining propranolol (Inderal) or pindolol (Visken) with
thioridazine (Mellaril) or
(Thorazine) may result in low blood pressure (hypotension) and abnormal heart
rhythms because the drugs interfere with each others' elimination and result in
increased levels of the drugs.
Dangerous elevations in blood pressure may occur
when clonidine (Catapres) is combined with a beta blocker, or when clonidine or beta blocker is discontinued after their concurrent use. Blood pressure should be closely
monitored after initiation or discontinuation of clonidine or a beta blocker
when they have been used together.
Phenobarbital and similar agents may increase
the breakdown and reduce blood levels of propanolol (Inderal) or metoprolol
(Lopressor, Toprol XL). This may
reduce effectiveness of the beta blocker.
Aspirin and other
antiinflammatory drugs (NSAIDs) (for example,
ibuprofen) may counteract the blood pressure reducing effects of beta
blockers by reducing the effects of prostaglandins. Prostaglandins play a
role in control of blood pressure.