First of all, it would be necessary to differentiate what is understood today by euthanasia and assisted suicide. euthanasia (from Latin euthanasia , and this from Greek εὐθανασία «Sweet death») is to cause the death of a terminally ill patient, to avoid his agony. It can occur with or without the consent of the patient, the latter as in the case of people in a coma in which a close relative decides. On the other hand, in assisted suicide a person is provided with the necessary means, including advice on lethal doses, but it is the patient himself who voluntarily ends his life. And what happened in Ancient Rome?
In Rome, suicide was not considered a crime or a sin against the gods, and, in certain situations, it was considered justifiable and pragmatic, as in the case of prominent figures to avoid public execution and preserve their dignity -remember the suicides of Cleopatra, Marco Antonio, Cato the Younger or Seneca-. However, suicide was explicitly prohibited for slaves, legionnaires and those accused of a crime punishable by death. The slaves, being the "property" of their masters, had no decision-making capacity and, moreover, their death was an injury to the interests of the masters. The soldiers who committed suicide were proclaimed traitors or deserters and all their property was confiscated in favor of the Republic or the Emperor of the day. In the case of the defendants, it was also an economic issue, since if they committed suicide before trial, no legal action could be taken to confiscate their property. Logically, faced with a foreseeable death sentence, the defendant preferred to take his own life and, at least, his family was not left with nothing. Until Emperor Domitian came along and decreed that if they killed themselves before the trial they would also lose all their property.
And what about the rest of the citizens of Rome? Well, according to what the historian Tito Livio tells us in «Ab urbe condita libri » and the Roman writer Valerio Máximo in «Factorum et dictorum memorabilium», if someone wanted to voluntarily end his life, he had to ask the Senate for permission, explaining his reasons. His case and his motivations were studied, and if it was considered that he was amply justified, it was authorized and even poison was provided free of charge. In case of not being sufficiently motivated, it was about giving solutions and convincing the suicide. If he proceeded without the pertinent authorization, he was buried in a common grave without honors and lost all the properties.
Sources:The Vintage News, Ancient Origins