Does a husband's divorce take effect if he swears to divorce in a text message while under the influence of Captagon, intending to intimidate rather than divorce?

As long as the message was for the purpose of threatening, not for enacting divorce, his divorce has not occurred. This is because writing a divorce is a metaphorical expression (kinayah) by which divorce does not occur unless there is an intention to enact it. Taking drugs is a heinous evil and a grave major sin, and the husband must hasten to repent.