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Patients undergoing chemotherapy frequently experience a number of side effects in response to the cytotoxic drugs administered during treatment, including nausea and/or vomiting (N/V) , hair loss, fatigue, cognitive dysfunction, anemia, and others. However, there is ample evidence that learning and cognition may play a role in the development of some of these side effects. For example, 20%-30% of patients undergoing chemotherapy continue to experience N/V merely in the setting and presence of chemotherapy equipment even after taking antiemetic medication.Three studies were conducted to better understand the acquisition of a learned, anticipatory nausea (AN) response. Studies 1 and 2 used the classical conditioning principle of overshadowing, in which a powerful stimulus is presented alongside a less salient stimulus during the acquisition phase. This results in a stronger relationship between the salient stimulus and the response, as compared with the less salient stimulus and response.In Study 1, nausea was induced in 50 healthy volunteers through motion sickness in a rotating chair. Subjects were divided into two groups and drank specific beverages prior to the rotation: One group received a different novel-tasting beverage (eg, elderberry, sloe) each day, and the other group drank only water. Nausea-related symptoms were recorded before and after the rotation. Results showed that subjects who drank the novel-tasting beverages reported less AN than those who drank water.Study 2 tested the protocol from Study 1 in cancer patients undergoing chemotherapy. Immediately prior to chemotherapy infusion, one group received a different novel-tasting beverage each day and the other group drank only water. Results again demonstrated that subjects in the group with different novel-tasting beverages experienced less AN than those who drank water.Study 3 researchers investigated whether patients' pretreatment expectations of developing nausea or medication-induced post-chemotherapy nausea (PN) were a better predictor of subsequent AN. Before their first round of chemotherapy (session #1) , subjects were surveyed about their degree of certainty of developing nausea. PN was measured after session #1, and then AN was measured before session #3 (Figure 1) .
Figure 1 AN before session #3
J. T. Hickok, J. A. Roscoe, and G. R. Morrow ©2001 Elsevier; U. Stockhorst, P. Enck, and S. Klosterhalfen ©2007 Baishideng Publishing Group.
-Which of the following is NOT accurate regarding antiemetic medications, which are administered to patients undergoing chemotherapy to treat or prevent N/V?

Question

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Patients undergoing chemotherapy frequently experience a number of side effects in response to the cytotoxic drugs administered during treatment, including nausea and/or vomiting (N/V) , hair loss, fatigue, cognitive dysfunction, anemia, and others. However, there is ample evidence that learning and cognition may play a role in the development of some of these side effects. For example, 20%-30% of patients undergoing chemotherapy continue to experience N/V merely in the setting and presence of chemotherapy equipment even after taking antiemetic medication.Three studies were conducted to better understand the acquisition of a learned, anticipatory nausea (AN) response. Studies 1 and 2 used the classical conditioning principle of overshadowing, in which a powerful stimulus is presented alongside a less salient stimulus during the acquisition phase. This results in a stronger relationship between the salient stimulus and the response, as compared with the less salient stimulus and response.In Study 1, nausea was induced in 50 healthy volunteers through motion sickness in a rotating chair. Subjects were divided into two groups and drank specific beverages prior to the rotation: One group received a different novel-tasting beverage (eg, elderberry, sloe) each day, and the other group drank only water. Nausea-related symptoms were recorded before and after the rotation. Results showed that subjects who drank the novel-tasting beverages reported less AN than those who drank water.Study 2 tested the protocol from Study 1 in cancer patients undergoing chemotherapy. Immediately prior to chemotherapy infusion, one group received a different novel-tasting beverage each day and the other group drank only water. Results again demonstrated that subjects in the group with different novel-tasting beverages experienced less AN than those who drank water.Study 3 researchers investigated whether patients' pretreatment expectations of developing nausea or medication-induced post-chemotherapy nausea (PN) were a better predictor of subsequent AN. Before their first round of chemotherapy (session #1) , subjects were surveyed about their degree of certainty of developing nausea. PN was measured after session #1, and then AN was measured before session #3 (Figure 1) .

Figure 1 AN before session #3
J. T. Hickok, J. A. Roscoe, and G. R. Morrow ©2001 Elsevier; U. Stockhorst, P. Enck, and S. Klosterhalfen ©2007 Baishideng Publishing Group.
-Which of the following is NOT accurate regarding antiemetic medications, which are administered to patients undergoing chemotherapy to treat or prevent N/V?

Quizplus · Accepted Answer

11ecba2d_0d5e_6ef2_a3bf_7bab6b922726_MD0008_00 N/V is an aversive stimulus. Antiemetic medications can be administered while patients are experiencing N/V to treat their N/V, or before chemotherapy to prevent N/V entirely. Either scenario may result in operant conditioning, in which the likelihood of an individual repeating a behavior is influenced by the outcome of that behavior (ie, by reward or punishment). Behavior is increased or maintained by reinforcement; positive reinforcement occurs when a desirable stimulus is applied, encouraging a behavior to happen again. For example, a young child receives a lollipop (desirable stimulus) for good behavior during a medical appointment, which increases the likelihood of future good behavior. In terms of the answer choice that is not accurate regarding antiemetic medications, an antiemetic that prevents a recurrence of N/V is inhibiting an undesirable stimulus, not adding a desirable stimulus; therefore, it is not an example of positive reinforcement. (Choice B) Negative reinforcement occurs when an undesirable stimulus is withdrawn, which encourages a behavior to happen again. For example, taking an antiemetic to treat (remove) current PN (unpleasant stimulus) increases the likelihood of the individual taking the medication in the future, which is negative reinforcement. (Choice C) Escape learning occurs when an individual learns how to terminate a current unpleasant stimulus. For example, an antiemetic that treats current PN may produce escape learning, as the individual learns that taking the medication stops N/V (unpleasant stimulus). (Choice D) Avoidance learning occurs when an individual figures out how to prevent experiencing the unpleasant stimulus in the future. For example, taking an antiemetic before chemotherapy, thereby preventing a recurrence of N/V (unpleasant stimulus), is an example of avoidance learning. Educational objective: In operant conditioning, the outcome of a behavior impacts the likelihood that the behavior will be repeated; behavior increases due to reinforcement, and it decreases due to punishment. Positive reinforcement refers to a desirable stimulus being applied, whereas negative reinforcement is an undesirable stimulus being withdrawn.

Passage Patients Undergoing Chemotherapy Frequently Experience a Number of Side Effects