Article Cite This: J. Chem. Educ. XXXX, XXX, XXX−XXX
pubs.acs.org/jchemeduc
Molecule of the Month: Relating Organic Chemistry Principles to Drug Action Paul C. Trippier* Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, Texas 79106, United States ABSTRACT: A molecule of the month extra credit assignment was introduced to a didactic introductory pharmacology and medicinal chemistry course for first-year pharmacy students. The structure of a clinically approved drug molecule was presented to students each month of the course after the first month. Students would answer questions pertaining to the name of the drug, its mechanism of action, specific aspects of its chemistry, and the indication(s) it is used in. Mean and median course scores were compared between classes of students who undertook molecule of the month questions and classes that did not. Extra credit earned from molecule of the month questions could not be applied to failing scores. Students overwhelmingly participated (85− 96%) in answering molecule of the month questions. Students who had the molecule of the month questions available performed significantly better than those that did not. The number of students receiving a final course score >91% increased more than 3fold, and no students attained a failing score (85% over the five modular exams, presentation, and participation, they are able to skip the final, achieving their averaged grade at this part of the course. The final exam is comprehensive over the whole course. Due to the modular design of the course all students are tested on all of the material taught. The molecule of the month (MOM) activity was introduced as an optional extra credit homework assignment administered through the Tophat software program. The MOM activity was assigned a nominal proportion of the course grade (maximum 3%) to encourage student participation. Each month, excluding B
DOI: 10.1021/acs.jchemed.8b00120 J. Chem. Educ. XXXX, XXX, XXX−XXX
Journal of Chemical Education
Article
and two classes who did participate were compared (Table 3). Differences between the classes were minimal with each class
course grades were compared between two control classes who did not have the MOM activity and two classes that did have access to MOM, over a four-year period. Deidentified composite PCAT scores were obtained as the mean for each class to determine variations in student ability. In addition, questions from the MOM activity were recreated for inclusion in the comprehensive final examination with suitable modification to the drug structure and question asked.
Table 3. Overall Course Grades, Participation in MOM, and Composite PCAT Parameter
■
Mean grade, % Mean grade MOM, % Class size Range Median grade, % Median grade MOM, % Number of fails Mean composite PCAT
RESULTS Students in the two classes that had access to the MOM activity (classes 3 and 4) participated in large numbers, with up to 96% of the students answering individual questions (Table 1), although interestingly some students did not answer all of the questions in a given month. Average participation for the two classes in each MOM was 90%, 87%, 92%, 92%, 96%, and 85%. In general, the correctness for pharmacology-based questions was greater than that for specific chemistry-based questions (compare mode of action (97%) to pharmaceutical salt (87%) in Table 1) mirroring the trend observed from modular exams. It is worth noting that the lower correctness for naming the MOM in Table 1 was due to students not including “hydrochloride” in the name. The online software allowed tracking of when students answered the MOM questions. One month was selected at random as a representative sample of student answering trends (Table 2). These data show a large proportion of the class
a
Within 24 h Within 7 days Within 14 days Within 21 days Within last 48 h of month Within last 24 h of month a
Number of Students
Incorrect Answers
Percentage of Class
20 4 26 14 25
1 1 5 1 11
12.7 2.5 16.5 8.9 15.9
35
9
22.3
Class 2 (No MOM)
Class 3 (MOM)
Class 4 (MOM)
83 N/Aa
81 N/Aa
86 84
88 87
153 70−96 83 N/A
163 50−96 81 N/A
174 72−100 86 85
157 71−100 89 89
0 72.2
8 70.7
0 76.1
0 70.2
Not applicable.
attending lectures scheduled at 11:30 a.m. and no known difference in age of students composing the classes. The course team comprised the same faculty, teaching the same material, for each of the four classes to minimize variables such as standards of teaching, strictness of grading, or differing teaching styles. The mean percentage grade of classes 1 and 2 was 83% and 81%, respectively (Table 3). When students participated in the MOM activity (classes 3 and 4), their mean percentage grade increased to 86% and 88%, respectively. When the MOM grade is removed from this calculation, the two classes had means of 84% and 87%, respectively. The median grade of classes which participated in the MOM activity (with MOM extra credit included) increased from 83% and 81% in classes 1 and 2, respectively, to 86% and 89% in classes 3 and 4, respectively. When MOM extra credit is removed, the median grades for classes 3 and 4 were 85% and 89%, showing a clear trend in increased grade that is not solely related to the extra credit available from the MOM activity. The impact of the MOM activity on course grades resulted in a higher range, with more students achieving 100%. Similar grade frequency distribution (including MOM extra credit for class 3 and 4) is seen between classes 2, 3, and 4 (Figure 1). Encouragingly, no students failed the course when they participated in the MOM activity. A list of deidentified composite PCAT scores, to protect student confidentiality, for each class was obtained by the investigator and a mean calculated. When the composite PCAT scores of each class are compared, all are within six points. While class 3 had the highest composite PCAT score of 76.1 and all students passed the course, a comparison can be made between class 2 (composite PCAT of 70.7) and class 4 (composite PCAT of 70.2). While class 2 with a slightly higher composite PCAT score but no MOM activity had eight students fail the course, an overall mean grade of 81% and a median grade of 81%, class 4 with a slightly lower composite PCAT score but access to the MOM activity had no students fail, an increased mean grade of 87% (MOM extra credit removed) and a median grade of 89%. Analysis of the grade ranges achieved by students in classes 2−4 (Table 4) clearly shows a greater number of students achieved higher scores in the PDA course when they had access to the MOM activity, suggesting a greater knowledge and understanding of the material taught. In class 2, who did not
Table 2. Student Answering Trendsa Time to Answer
Class 1 (No MOM)
Data are representative of one question in one MOM activity.
(38.2%) answered in the last 2 days of the month, possibly when reminded of the deadline by faculty or classmates. Of those students answering the MOM questions in the last 2 days of the month, more were likely to answer incorrectly than those answering early in the month. A third of students answering in the last 2 days were incorrect, compared with just 12% incorrect of students who answered in the first 3 weeks. Students did not get immediate feedback on their answer so as to prevent one student from sharing the correct answer with the rest of the class, or a portion of the class. Feedback was presented at the end of the month when all answers had been marked. Feedback was via answer sheet and the explanation posted onto the e-learning system and, in the case of very poor performance by the class, in class discussion. When students were presented with a similar question in the exam, based on a different molecule, performance increased. In the example of assigning the stereochemistry of a clinical drug molecule, student performance increased from 40% correct to 68% correct. Overall course grades (modular exams, presentations, participation, final exam (if sat), and MOM) between two classes (1 and 2) who did not participate in the MOM activity C
DOI: 10.1021/acs.jchemed.8b00120 J. Chem. Educ. XXXX, XXX, XXX−XXX
Journal of Chemical Education
Article
Figure 1. Grade distribution frequency of classes 2, 3 and 4.
knowledge of medicinal chemistry and apply these principles to clinical relevance. This provides an excellent opportunity to evaluate student knowledge outside of an exam setting. The MOM questions can be specifically designed to target areas of known difficulty (salts, stereochemistry, etc.) in the integrated PDA course. In the representative MOM activity presented in Table 1, of particular value was the nature of the responses for the effect of forming the pharmaceutical salt on physicochemical properties. While 87% of the students answered correctly, the open format nature of the question revealed that several of the students arrived at this answer through incorrect reasoning, showing that the class as a whole had an unclear understanding of the effects of organic and inorganic salts on lipophilicity. This allows faculty to return to this subject in the lectures to clarify the material. Setting exam questions that evaluate the students understanding of the same content, but applied to a different drug molecule, allows further determination of not just the students’ comprehension of the material but also their ability to apply the concept to a range of drug molecules, thus assessing knowledge at a higher Bloom’s taxonomy level. The topic of stereochemistry is well-suited for this analysis as assigning a stereocenter cannot simply be memorized; students must understand the Cahn−Ingold−Prelog priority rules. When comparison is made between the MOM activity answers and the modular exam answers, 40% of students assigned the stereochemistry of a drug molecule correctly in the MOM activity. As the students were required to state the reasoning behind their answers rather than just R or S, analysis of their application of knowledge was possible. The student’s answers clearly showed that many students were having difficulty determining functional group priorities and remembering clockwise versus anticlockwise assignment of stereochemistry. This topic was reiterated to the class as a whole with further examples. When the students were tested on this concept in the modular exam, the number of students answering correctly increased to 68% when a different drug molecule was the subject of the question. When class 2 (no MOM activity) encountered a similar question in an exam setting, only 48% of students answered correctly, which would indicate many of the students guessing at the answer. The increase in correct answer between class 2 (no MOM) to class 4 (MOM), 48% to 68%, was found to be statistically significant (p < 0.05) on the basis of commonly available normal distribution tables. Comparison of student performance in the PDA course and the effect of the MOM activity shows a clear increase in mean percentage grade by 3−6 points when students participate in the MOM, but when the extra MOM grade is removed from the overall course grade (Table 3). Class 2, without access to
Table 4. Number of Students Scoring in Grade Ranges of Classes 2−4 MOM Course Grade, %
No MOM Class 2
Class 3
Class 4b
a
8 35 35 35 34 16
0 12 39 36 34 53
0 8 26 21 39 63
85% while in classes 3 and 4, who did have access to the MOM activity, 87 and 102 students, respectively, achieved grades >85%. Similarly, the number of students scoring
