new drugs on the sick

Is it licit to experiment with new drugs on the sick

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I have a friend who is sick with AIDS. The doctors who see him offered to try a treatment, which doesn’t yet have many guarantees, and they don’t know all the side effects. Is it licit for him to be open to this? Thank you for your perspective.


In order to respond to your consultation we should recall the general principles on the delicate topic of experimentation on human beings.

  1. What is clinical experimentation?

By clinical experimentation we mean the collection of those acts that are done on man in order to verify the validity of each new medical act, either with a preventative, diagnostic, or curative aim, or with the goal of acquiring physiopathological knowledge. Therefore, one can distinguish two fundamental categories: therapeutic experimentation and scientific investigation. What could justify this type of investigation?[1]

First of all, let us call upon the interest of medical science. To attempt to enhance science is not a moral problem as long as it does not harm the rights of the other and does not violate any moral rule of absolute value (otherwise, even though one intends and pursues rightly the increase of knowledge, this method would not be morally admissible).

It can also be argued that it is in the interest of the patient to discover new methods to cure his or her disease. This also has limits since the patient is not the absolute master of himself, neither of his body nor of this spirit. He cannot, therefore, freely dispose of himself as he pleases. He possess the right of “use,” limited by the natural purpose of the faculties and strengths of his human nature. The patient does not have, therefore, the right to compromise his physical or psychological integrity through experiences or medical research when these interventions entail in and of themselves or as a consequence of them: destructions, mutilations, injuries, or serious dangers. Additionally, we should observe the hierarchy of values, in so far as the rules of ethics demand it (for example, man cannot permit medical acts that, undoubtedly, suppress  heavy defects or physical or mental illnesses, but pose at the same time a permanent abolition or considerable and lasting decrease in liberty).

 Finally, let us call upon the interest of the community. But also this has its limits: “Man,” says Pius XII, “in his personal being, is not subordinate, in the final analysis, to the utility of society, but on the contrary, the community is for man.”

  1. Conditions for licit experimentation

Taking into account these limits we can establish certain conditions for the licitity of clinical experimentation, that is to say, on man[2]:

1st- First of all, seriousness is required: the research and experimentation should have serious objectives. It should exclude, therefore, experimentation motivated by simple curiosity, with prospects of therapeutic application. It is clear that we cannot consent to exposing someone to dangers or risks to life for inconsistent motives.

2nd- Next, experimentation on humans should be preceded by experimentation on beings inferior to man, unless this will prove impossible. Pius XII says, “It is an obvious law that the application of new methods to a living man should be preceded by research on a cadaver or a study model or by experimentation on an animal,” whenever this process does not prove impossible, insufficient, or practically unfeasible.

3rd- We should have the consent of the patient: because the doctor does not have a greater right than the one given by the patient. It is necessary to distinguish distinct cases of patients[3]:

  1. Experimentation on the sick.

When we try experimentation with a therapeutic aim (with a drug that has received a guarantee of safety in the laboratory experimentation, obtaining the license to use it on man, even though its use on man has not yet been validated definitively in the same way) the doctor can use it even without further specific consent, basing this on the consent given in the moment in which the patient has entrusted  themselves to that hospital or to that specific doctor.

With an experimental aim. If, on the other hand, it is not applied principally for the good of the patient but in order to validate the drug in itself or for the benefit of the researcher, then it should be preceded by safety experiments, licenses to use it on man, and with the informed consent of the patient.

On the other hand, when the use of a drug or method not yet validated (definitively by experimentation) represents the last chance for an extreme attempt to save the life of a patient, the experimental nature coincides with the therapeutic because the drug represents the only possible therapy. The consent can be assumed implicitly and tacitly granted in the general will of the patient and of the relatives when they want everything possible to be done to save the life of the patient. Thus, for example, what Pasteur did to use the rabies vaccine on a non-recoverable boy.

b) Persons incapable of consent (such as the disabled, mentally ill, terminally ill, and also children and legal minors): the inviolability of life and indispensability of their lives and bodies does not change. They cannot be objects of the research and experimentations that require informed consent. For them only therapeutic experimentation is licit, as we have pointed out in the previous point.

c) Voluntary healthy persons. It would be valid to apply the principle of social solidarity, but with precise conditions: 1st– with the free, informed, and explicit consent of the volunteer; 2nd– the risk to which the volunteer is exposed cannot and should not surpass the threshold of their life and substantial integrity; 3rd– respecting the law of proportionality between the risks and the benefits (experiments for the sake of simple curiosity are excluded); 4th– the expert should retain the ability to stop the experiment at any moment, be it if the volunteer withdraws consent or if unforeseen risks arise; 5th– any degrading or immoral circumstance, and all dishonest intentions, with or without the consent of the subject on whom the research is done, should be excluded.

d) On the researcher themselves. The same principles are valid as for those for research on healthy volunteers. It should be added as a condition that the presence of another person is provided for in order to attend to any unforeseen risk.

e) On prisoners. The boundaries for their life and substantial integrity remain in place. They can be offered, in exchange for volunteering in the experiment, benefits on their sentences, but always and only when they are well informed and without any type of deception.

f) On human embryos and fetuses: “Research and experimentation on human embryos and fetuses is subject to the applicable ethical norms for children already born and for each human subject. In particular, research, that is, the observation of a certain phenomenon during pregnancy, can be permitted only when there is moral certitude that it will not cause harm to either the life or integrity of the child who is to be born, nor to the mother; and with the condition that the parents have agreed to give their consent.

Experimentation, on the other hand, is acceptable only if the objectives are clearly therapeutic due to a lack of other possible treatments. No purpose, however noble in itself (such as the anticipation of some scientific benefit, for other human beings or for society), may in any way justify experimentation on living human embryos or fetuses, viable or not, inside of the mother’s womb or outside of it. Informed consent, normally required for clinical experimentation on an adult, cannot be given by the parents, who don’t have the right to dispose of neither of the physical integrity nor of the life of the child who is to be born. Moreover, experimentation on embryos or fetuses always involves a risk (and the majority of the time an expectation) of harm to their physical integrity or directly of their death. To use a human embryo or a fetus as an object or instrument of experimentation represents an offense contrary to the dignity of human beings.”[4]

Fr. Miguel A. Fuentes, IVE


Pius XII, Discurso al Primer Congreso Internacional de Histopatología del sistema nervioso (14/09/1952); in: Pío XII y las ciencias médicas, op. cit., 125 ss.

 Ciccone, Lino, Salute e malattia, Ares, Milano 1986, 270-319.

[1] Pius XII, Discurso a 1º Congreso Internacional de Histopatología del sistema nervioso, in: Pío XII…, pp. 125 ss.

[2] Cf. Ciccone, Salute e malattiaop. cit., pp. 298ss.

[3] Cf. Sgreccia, Manuale di Bioetica, Vita e Pensiero, Milano 1991, op. cit., I, p. 415ss.

[4] Pontifical Council for Healthcare Workers, Carta a los Agentes de Salud, n. 82; cf. Donum vitaeEvangelium vitae, n. 63.

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