Guanabenz (Systemic)

Brand Names : Wytensin

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For guanabenz, the following should be considered:

Allergies - Tell your doctor if you have ever had any unusual or allergic reaction to guanabenz. Also tell your health care professional if you are allergic to any other substance, such as foods, preservatives, or dyes.

Pregnancy - Guanabenz has not been studied in pregnant women. However, studies in rats have shown that guanabenz given in doses 9 to 10 times the maximum human dose caused a decrease in fertility. In addition, 3 to 6 times the maximum human dose caused birth defects (in the skeleton) in mice, and 6 to 9 times the maximum human dose caused death of the fetus in rats. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding - It is not known whether guanabenz passes into the breast milk. However, this medicine has not been reported to cause problems in nursing babies.

Children - Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of guanabenz in children with use in other age groups.

Older adults - Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of guanabenz in the elderly with use in other age groups. However, dizziness, faintness, or drowsiness may be more likely to occur in the elderly, who are usually more sensitive to the effects of guanabenz.

Other medicines - Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking guanabenz, it is especially important that your health care professional know if you are taking any of the following:

• Beta-blockers (acebutolol [e.g., Sectral], atenolol [e.g., Tenormin], betaxolol [Kerlone], bisoprolol [e.g., Zebeta], carteolol [e.g., Cartrol], labetalol [e.g., Normodyne], metoprolol [e.g., Lopressor], nadolol [e.g., Corgard], oxprenolol [e.g., Trasicor], penbutolol [e.g., Levatol], pindolol [e.g., Visken], propranolol [e.g., Inderal], sotalol [e.g., Sotacor], timolol [e.g., Blocadren]) - Effects on blood pressure may be increased. Also, the risk of unwanted effects when guanabenz treatment is stopped suddenly may be increased

Other medical problems - The presence of other medical problems may affect the use of guanabenz. Make sure you tell your doctor if you have any other medical problems, especially:

• Heart or blood vessel disease - Lowering blood pressure may make some conditions worse

• Kidney disease or
• Liver disease - Effects of guanabenz may be increased because of slower removal of guanabenz from the body