Triprolidine geometrical isomers

An example of a drug with a geometrical isomer is the antidepressant zimeldine (Fig. 2.2). The lack of free rotation about the double bond ensures that the stereochemistry of this drug and and its isomer is different. Zimeldine is the only drug used. Other drugs which could also have geometric isomers of this type include amitriptyline and triprolidine. 

S AR of Triprolidine. It has been established that the pharmacoligic activity solely resides in the geometric isomer wherein the pyrrolidinomethyl moiety is present as trans-to the corresponding 2-pyridyl functional moiety as given below ... 

Figure 2.14 Diethylstilbestrol and triprolidine and their geometrical isomers.

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