WHEN STUART CLOSE MENTIONS ABOUT BOENNINGHAUSEN'S OBSERVATIONS ( addendum Dr. Nash in his Materia Medica and Allen keynotes reference)
Deficient reaction or diminished susceptibility may exist in a case or appear during treatment and constitute a condition requiring special treatment. This is especially true in the treatment of chronic diseases, where improvement ceases and well selected remedies do not seem to act. Under such circumstances it may sometimes be necessary to give a due of what is called an "intercurrent remedy." Bœnninghausen mentions as appropriate in such cases: Carbo veg., Lauroc., Mosch., Op., Sulph. To these may be added the typical nosodes: Medorr., Psor., Pyrog., Tuberc., Syphil.,. and also Thuja. The choice of any particular one of these remedies must be governed by the history and symptoms.
Addendum :
Dr. Nash
The fact that Opium is capable of banishing pain, or, rather, I should say, rendering the organism incapable of sensing pain, is one of the chief indications for its use in homœopathic therapeutics. There is not only complete absence from pain, but as complete unsusceptibility to general drug action. You know that we are told that when the seemingly indicated remedy does not act give Sulphur. Now it may be that Opium is a better remedy to give, if all there is of the case is that there seems to be no vital reaction. Sulphur would be likely to be the best remedy if the lack of reaction were due to some psoric taint; but even here all the symptoms must be taken into account. Laurocerasus is another remedy to arouse reaction when it seems to depend upon excessively low vitality. Psorinum may succeed in psoric obstructions to vital reactions when Sulphur fails. There is nothing to be more condemned in homœopathic prescribing than routinism.
Dr.HC Allen mentions Valeriana also bring in such conditions
Something morefrom Dr.Nash
Capsicum, lack of reaction in persons of lax fibre."
Opium, in patients where there is no pain; stupidity and drowsiness.
Valerian and Ambra in nervous affections, well chosen remedies fail.
Carbo vegetabilis, collapse, coldness of knees, breath; perfect indifference.
Sulphur and Psorinum, where Psora complicates and hinders reaction.
Each one of these remedies may he called for in defective reaction, and there may be many more, and in each case, as with all remedies elsewhere, symptoms must decide whichone.