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Alpha Blockers
July 16, 2009 | Leave a Comment
Type of Drug
Alpha Blockers
Brand Names
Generic Ingredient. Alfuzosin Uroxatral
Generic Ingredient: Terazosin Hydrochloride Hytrin
Prescribed For
High blood pressure (terazosin) and benign prostatic hyperplasia (BPH) (alfuzosin and terazosin).
General Information
Alpha blockers block nerve endings known as alpha, receptors. They reduce blood pressure by dilating (widening) and reducing pressure within the blood vessels. The maximum blood-pressurelowering effect of terazosin is seen between 2 and 6 hours after taking a single dose. Terazosin’s effect lasts for 24 hours.
In BPH, alpha blockers work by relaxing smooth muscles in the prostate and neck of the bladder. This effect is produced by blockage of alpha, receptors in the affected muscles. Despite the fact that terazosin alleviates the urinary symptoms of BPH, the drug’s long-term effect on complications of BPH or the need for urinary surgery is not known. Alpha blockers are broken down in the liver.
Cautions and Warnings
Do not take alpha blockers if you are allergic or sensitive to any of their ingredients.
Alpha blockers may cause dizziness and fainting, especially after the first few doses. This is known as the “first-dose effect” and may be minimized by limiting the first dose to 1 mg at bedtime. The first-dose effect occurs in about 1 % of people and may recur if the drug is stopped for a few days and then restarted.
Do not take alfuzosin if you have moderate to severe liver disease since this can drastically increase blood concentrations of the drug.
Alpha blockers should be taken with caution if you have kidney disease, since blood concentrations may be increased by 50%.
Do not take these medicines if you are already taking an alphablocker for either high blood pressure or prostate problems.
Terazosin may slightly reduce cholesterol levels and improve the high-density lipoprotein (HDL) to low-density lipoprotein (LDL) ratio, a positive step for people with blood-cholesterol problems.
Terazosin may reduce the counts of red and white blood cells.
People taking terazosin may experience a weight gain of about 2 lbs.
Possible Side Effects
Alfuzosin
✓ Most common: dizziness, fatigue, upper respiratory infection, and headache.
✓ Less common: pain, abdominal pain, upset stomach, constipation, nausea, impotence, bronchitis, sinusitis, sore throat, low blood pressure, dizziness, and fainting.
✓ Rare: rash, rapid heartbeat, chest pain, and painful and persistent erection. Contact your doctor if you experience any side effect not listed above.
Terazosin
✓ Most common: dizziness, weakness, and headache.
✓ Rare: depression, reduced sex drive or abnormal sexual function (including painful and persistent erection), fluid retention, and weight gain. Contact your doctor if you experience any side effect not listed above.
Drug Interactions
• When taken with other blood-pressure-lowering drugs, terazosin severely reduces blood pressure.
• Verapamil may increase blood levels of terazosin.
• Antifungal drugs such as itraconazole and ketoconazole and protease inhibitors interfere with the breakdown of alfuzosin in the liver, raising the amount of drug in the blood.
• Alfuzosin moderately increases the amount of diltiazem in the blood.
• Alpha blockers should not be taken with ritonavir.
Food Interactions
Alfuzosin should be taken with food.
Usual Dose
Alfuzosin: one 10-mg tablet taken after the same meal every day. Do not crush or chew the tablets.
Terazosin: starting dosage-1 mg at bedtime. Dosage may be increased in increments of 1-5 mg to a total of 20 mg a day. Dosages of 10 mg a day are generally needed to control the symptoms of BPH.
Overdosage
Symptoms may include drowsiness, poor reflexes, and very low blood pressure. Take the victim to a hospital emergency room. ALWAYS bring the prescription bottle or container.
Special Information
Take alpha blockers exactly as they are prescribed and do not stop taking it unless directed to do so by your doctor. Avoid over-the-counter drugs that contain stimulants because they may increase your blood pressure.
Alpha blockers may cause dizziness, headache, and drowsiness, especially 2-6 hours after taking your first dose, though these effects may persist after the first few doses. Wait 12-24 hours after taking the first dose before driving, operating machinery, or performing any other task that requires intense concentration. You may take alpha blockers at bedtime to minimize this problem.
Some people undergoing eye surgery who take alpha blockers can experience an unusual effect called “floppy iris syndrome.” Make sure to tell your eye surgeon if you are taking or have ever been treated with an alpha blocker. There is no benefit to stopping alpha-blocker treatment before cataract surgery.
Prostate cancer and BPH may have similar symptoms. Talk to your doctor about ruling out prostate cancer before beginning treatment for BPH.
Call your doctor if you develop severe dizziness, heart palpitations, or any bothersome or persistent side effect.
If you forget a dose, take it as soon as you remember. If it is almost time for your next dose, skip the forgotten dose and continue with your regular schedule. Do not take a double dose.
Special Populations
Pregnancy/Breast-feeding: Alfuzosin is not indicated for use in women. Large dosages of terazosin damage the fetus in animal studies. When alpha blockers are considered crucial by your doctor, their potential benefits must be carefully weighed against their risks.
It is not known if terazosin passes into breast milk. Nursing mothers who must take this drug should use infant formula.
Seniors: Seniors may be more sensitive to the effects of terazosin.