Agonist:A drug that binds to a receptor of a cell and triggers a response by the cell, mimicking the action of a naturally occurring substance.Antagonist:A chemical that acts within the body to reduce the physiological activity of another chemical substance or hormone.K.Radiation TherapyoRadiation therapy is usually reserved for people who have some tumor remaining after surgery and do not respond to medications. Because radiation leads to a slow lowering of GH and IGF-I levels, these patients often also receive medication to lower hormone levels. The full effect of this therapy may not occur for many years.oThe two types of radiation delivery are conventional and stereotactic. Conventional radiation delivery targets the tumor with external beams but can damage surrounding tissue. The treatment delivers small doses of radiation multiple times over 4 to 6 weeks, giving normal tissue time to heal between treatments.L.Which treatment for acromegaly is most effective?oIf the tumor has not yet invaded surrounding nonpituitary tissues, removal of the pituitary adenoma by an experienced neurosurgeon is usually the first choice. Even if a cure is not possible, surgery may be performed if the patient has symptoms of neurological problems such as loss of peripheral vision or cranial nerve problems. After surgery, hormone
levels are measured to determine whether a cure has been achieved. This determination can take up to 8 weeks because IGF-I lasts a long time in the body's circulation. If cured, a patient must be monitored for a long time for increasing GH levels.M.Points to RememberAcromegaly is a hormonal disorder that results from too much growth hormone (GH) in the body.In most people with acromegaly, a benign tumor of the pituitary gland produces excess GH.Common features of acromegaly include abnormal growth of the hands and feet; bone growth in the face that leads to a protruding lower jaw and brow and an enlarged nasal bone; joint aches; thick, coarse, oily skin; and enlarged lips, nose, and tongue.Acromegaly can cause sleep apnea, fatigue and weakness, headaches, impaired vision, menstrual abnormalities in women, and erectile dysfunction in men.Acromegaly is diagnosed through a blood test. Magnetic resonance imaging (MRI) of the pituitary is then used to locate and detect the size of the tumor causing GH overproduction.The first line of treatment is usually surgical removal of the tumor. Medication or radiation may be used instead of or in addition to surgery.
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- Spring '14
- Nursing, Headaches, Nasal bone, Somatostatin, Pituitary adenoma