| name: | Guanethidine |
| also known as: | Ismelin; Reserpine (Rauwolfia alkaloid); Adrenergic Antagonist |
| also see: | Alpha Blockers; Beta Blockers; Diuretics; Vasodilators; Ace Inhibitors; Ace II Inhibitors; High Blood Pressure |
| description: | Guanethidine is not an alpha or beta stimulator. He does however block the release of norepinephrine at sympathetic nerve endings which in effect, is the same as an alpha or beta stimulator. It is primarily used in the treatment of high blood pressure. Reserpine works slightly differently then guanethidine. Reserpine blocks the transport of norepinephrine. It is rarely used in the treatment of high blood pressure. The nervous system is comprised of the central nervous system, brain and spinal cord, and the peripheral nervous system, motor and autonomic. The motor system, also called somatic nervous system, moves skeletal muscle. The autonomic system is further divided into the sympathetic nervous system and parasympathetic nervous system. The sympathetic nervous system is the "flight or fight" system. The parasympathetic nervous system is the "rest and digest" system. The sympathetic nervous system is triggered by chemicals variously called: catecholamines, adrenergic agonists, or sympathomimetics. Within this system are four types of receptors, alpha 1, alpha 2, beta 1, and beta 2 and each receptor type effects a certain part of the body. Some catecholamines trigger all four receptors while others are more selective in their action. Knowing this, certain sympathomimetics can be used as drugs to treat a particular problem. Alpha 1 receptors are involved with vasoconstriction, decrease intestinal motility, bladder sphincter contraction, ejaculation, uterine contraction, and pupil dilation. Alpha 2 receptors primarily work to inhibit further alpha 1 action as a negative feedback loop. Beta 1 receptors work primarily to stimulate the heart to contract more forcibly. Beta 2 receptors work on the heart to contract, too, and also work to relax lung smooth muscle leading to lung airway dilation (bronchodilation), uterus relaxation and bladder relaxation. |
| signs & symptoms: | Side effects of guanethidine include drop in blood pressure when standing up and sexual dysfunction. High blood pressure can be divided into three stages: Stage 1 - Mild: Systolic BP 140-159 and/or Diastolic BP 90-99 Stage 2 - Moderate: Systolic BP 160-180 and/or Diastolic BP 100-110 Stage 3 - Severe: Systolic BP > 180 and/or Diastolic BP > 110 |
| treatment: | Usually given orally. |
skynetMD suggests the following:
| if: | If you have questions, problems, or concerns regarding any medication |
| go to: | Go to the phone and ask your pharmacist or your doctor, or go to the doctor. |
Last updated 1/4/2005