In ecology, commensalism is a class of relationship between two organisms where one organism benefits without affecting the other. It compares with mutualism, in which both organisms benefit, amensalism, where one is harmed while the other is unaffected, and parasitism, where one benefits while the other is harmed.n ecology, commensalism is a class of relationship between two organisms where one organism benefits without affecting the other. It compares with mutualism, in which both organisms benefit, amensalism, where one is harmed while the other is unaffected, and parasitism, where one benefits while the other is harmed.
Drug interactions also may occur when two drugs that have similar (additive) effects or opposite (canceling) effects on the body are administered together. For example, there may be major sedation when two drugs that have sedation as side effects are given, for example, narcotics and antihistamines.
Incompatibility is an undesirable reaction that occurs between the drug and the solution, container or another drug. The two types of incompatibilities associated with intravenous administration are physical and chemical [1].efinition of interactions A drug interaction describes the alteration of a drug effect due to the influence of another substance (i.e. drug, chemical substance, nutrition) resulting in a solution that is no longer optimal for the patient after the substances are mixed 2.