Which of these statements best describes the synergistic interaction effect?
a. an interaction where two or more medicines taken together have no effect on one another
b. an interaction between two or more medicines that increases their effectiveness
c. an interaction where two or more medicines taken together produce an unexpected result
d. an interaction between two or more medicines that decreases their effectiveness

B is perhaps the best answer of the suggestions. A synergistic interaction is where the result of two or more medicines taken together is greater than the impact that would have happened if the medicines had been separately at the same dosage. This can potentially increase the effectiveness, although it can have negative results as well as positive. The result could also be unexpected, so C could also be a correct answer.