Answer:
Synergistic drug interaction.
Explanation:
The drug can be taken alone or in combination with the other drugs depending on the severity of the disease or the drug interaction. The drug interaction can be harmful or beneficial.
Synergistic drug interaction may be defined as the drug interaction in which the overall effect of the drug increase in presence of the other drug. Nilatall has no effect but when taken together with somatall increase the overall effect of somatall.
Thus, the answer is synergistic drug interaction.