Premenstrual Disorders

homology : A similarity attributable to a com- mon origin. analogy : A resem- blance to some char- acteristics between things that are other- wise unlike.

nephrine transmitters, it was less effective. Treating neurotransmit- ters that did not need to be treated caused unnecessary side effects. The more parts of the body altered by a medication, the greater the number of side effects. Some of imipramine’s side effects—sweating, heart palpita- tions, dry mouth, blurry vision, and difficulty in urinating—were caused by the body reacting as if it was in an emergency situation. Just as if a ti- ger was stalking it in the jungle, the patient’s body was ready to run or to fight at any time. The need for a drug with fewer side effects was still apparent.

hypertension : High blood pressure.

When drugs are discovered that have a desired effect but have some problem side effects as well, researchers continue their search for a better alternative by creating similar chemicals. This type of research is called homology , because the researchers use the fun- damental structure of the original chemical but try to change some part of the formula. Because this is the easiest route toward a de- sired goal, much research starts here. New drugs may also be developed using analogy . In this case, researchers look for substances that will function similarly. In other words, if they have an antidepressant that affects the brain by in- fluencing the levels of available serotonin, they look for other sub- stance structures that will do the same thing. Like the first antidepressants, monoamine oxidase inhibitors (MAOIs) worked well when treating depression. Although research­ ers have proven that these drugs inhibit monoamine oxidase that works in the neurons of the brain, exactly how the drugs work is not known. If the patient has hypertension , MAOIs need to be used with much caution. This meant that the drug’s use was limited for many patients. Research continued for yet another alternative.

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History of Zoloft and Prozac