The Effects of Drugs on Mood - Essay Example

Psychopharmacology is the study of the effects of drugs on mood, sensation, consciousness, or other psychological or behavioral functions (Association for Better Living and Education International, 2003). Many psychoactive drugs affect the psyche or personality of a person by affecting his brain chemistry. Drugs like Zoloft, Vioxx, Celebrex, Viagra, Prozac, and Paxil all fall into this category.

     Vioxx, a Cox-2 inhibitor primarily meant for pain relief in Osteoarthritis and other types of pain, was withdrawn by its maker Merck last year after studies proved that Vioxx doubled the risk of heart attack or stroke in patients taking the medicine to prevent colon polyps that cause cancer. COX-2 inhibitors block the action of an enzyme used throughout the body to make a large and diverse family of compounds called prostanoids that are involved in regulating myriad physiological actions, including inflammation, blood clotting, and protection of the stomach lining from the destructive effects of digestive acids (Brown, 2004). Congress is questioning why the FDA didn't force Merck to study Vioxx's heart risk sooner. Merck is facing hundreds of lawsuits and potentially billions of dollars in damages from Vioxx. Pfizer, the maker of Celebrex, which is a rival of Vioxx, has not yet pulled the popular painkiller off the market, although Celebrex also increases cardiovascular diseases. Celebrex, approved by the Food and Drug Administration in 1998 for arthritis pain, has been prescribed to 27 million Americans and is the world's most widely prescribed arthritis drug (“Pfizer cites”, 2005).

     Zoloft, Prozac, and Paxil, known as selective serotonin reuptake inhibitors or SSRIs, are antidepressants and act by enhancing the signals in nerves that transmit messages with serotonin, a neurotransmitter. Neurotransmitters, which are chemicals that are used to relay and modulate electrical signals between a neuron and another cell, are removed from the synaptic cleft by a process called reuptake. These drugs act on the neurotransmitter serotonin within the cell by delaying the reuptake process, thereby increasing the serotonergic effect.

     The common side effects of these drugs include nausea, diarrhea, headache, anxiety, insomnia, sexual dysfunction, and reduced motivation. The regulators at the Food and Drug Administration ordered that all antidepressant drugs carry a prominent ‘black box’ warning to alert doctors that the medications increase the risk of suicidal thoughts and behavior among children and adolescents. According to a study conducted by the FDA, children taking antidepressants have a 4 percent risk of suicidal thoughts and behavior, compared with a 2 percent risk among children getting placebos. Although Prozac is effective in treating children's depression,  the black box warning suggests that the drug might increase suicidal thoughts among some children and teenagers while simultaneously relieving depression (Vedantam, 2004).

     Pfizer’s Viagra (Sildenafil citrate), which is a selective inhibitor of cGMP-specific phosphodiesterase type 5 (PDE5), is a popular erectile dysfunction prescription medication and has various side effects like heart attack, blood clots, irregular heart rhythm, stroke, chest pain, blood pressure changes, and sudden death. The molecular structure of sildenafil is similar to that of cGMP and acts as a competitive binding agent of cGMP in the corpus cavernosum, resulting in better erections. Viagra use has been linked to over 40 reports of a condition called NAION (non-arteritic ischemic optic neuropathy), which can lead to loss of vision and blindness (“Viagra Deaths”, n.d.). The FDA has ordered updated labeling for Viagra, Cialis, and Levitra after it was criticized for not taking sufficient action to warn healthcare professionals and consumers of the risk of loss of vision among Viagra users.

Importance of Psychopharmacology in Psychology

There is an increasing need for an up-to-date understanding of medications and their use in patients who suffer from both medical and psychiatric disorders. Read More