Guanabenz is a generic drug used to treat high blood pressure in adults and children over the age of 12. It relaxes blood vessels to allow blood to flow more easily and slows the heart rate. Guanabenz cannot cure high blood pressure, but might keep it under control to reduce the risk of a heart attack or stroke. It works on neurotransmitters in the brain to block certain chemicals that cause hypertension.
When the heart pumps blood, it creates pressure on artery walls. If the pressure goes too high, damage could occur. Two aspects of blood pressure are measured and related to each other. Systolic pressure represents the upper number of a blood pressure reading when the heart pumps. Diastolic, the lower number, measures the resting heart rate between each contraction. Normal blood pressure should read 120 or less for systolic over 80 or under for diastolic.
Guanabenz might be prescribed when the systolic number ranges above 120. Systolic readings between 140 and 159 define stage one high blood pressure, and over 160 means the patient might have stage two hypertension. Diastolic pressure for stage one disease ranges between 90 and 99, and over 100 in stage two disorders. High blood pressure might be present when only the upper or the lower number measures above normal.
When a patient begins taking this drug, it should not be stopped suddenly, because a sudden rise in blood pressure might occur. Abrupt cessation of the drug might also produce withdrawal symptoms, such as confusion, nervousness, and headache. If side effects become troublesome, the patient should check with a doctor before missing doses of guanabenz or discontinuing its use.
Most side effects are minor, with dizziness the main problem reported, which is more common in the elderly. Patients might feel lightheaded, especially when they rise from a sitting position too quickly. These effects might become worse on hot days or after exercise. The drug might also cause dry eyes and mouth, nausea, and loss of interest in sex or the inability to engage in sexual intercourse.
If dizziness causes fainting, a doctor’s advice should be sought. Serious side effects of guanabenz also might cause the heart to beat faster or slower than normal and swelling around the feet. Signs of an allergic reaction to the drug include trouble breathing, a rash, or swelling in the face or mouth. Some patients need to urinate more frequently while taking this medication.
Doctors typically tell patients with high blood pressure to make lifestyle changes along with drug therapy. A low-fat, low-salt diet with little red meat might help control hypertension. Exercise and reducing weight might also help, along with giving up smoking. Stress is linked to hikes in blood pressure, and relaxation techniques might help control anxiety.