Answer: Synergistic interactions occur when the combined effect of two drugs is greater than the sum of each drug's individual activity (Cokol et al., 2011; Kalan and Wright, 2011). A beneficial synergistic effect occurs when two different types of antibiotics that work in very different ways are combined, such as penicillin G and an aminoglycoside antibiotic. Potentiation is an interaction in which the effect of only one of the two drugs is increased.In toxicology, synergism refers to the effect caused when exposure to two or more chemicals at one time results in health effects that are greater than the sum of the effects of the individual chemicals.