After the development of a holistic science, how to administer it to the patients so that this science can be beneficiary at its most utility was a question. Master Hahnemann developed lucid guidelines regarding how to administer medicines in which dose and in what potency.
KEYWORDS :- posology, susceptibility, potentisation, dilutions.
The term, posology originates from the greek terms ‘posos’ and ‘logos’. Poso, means how much, i.e. the science or doctrine of doses. Logos means discourses or study.
Posology is the doctrine of doses of medicine. According to homoeopathy, a dose is the particular preparation of medicine used, the quantity form of preparation and the administration of the medicine.  Basically, a homoeopathic dose includes potency, quantity, form and number of administration of medicine.
In homoeopathy, it bears some speciality. Small doses and homoeopathy are commonly regarded as synonymus terms. It is almost an accepted fact that the subject of doses is a very important one. The essential factors are:
- Doses and the related subject of potentisation.
All are inter-mingled with each other. The subject of doses can be examined from two sides:
- Doses in relation to pharmacy.
- The doctrine of doses in relation to homoeopathic philosophy (i.e. Organon of Medicine and The Chronic Diseases). [3, 4, 5]
VIEWPOINT OF MASTER HAHNEMANN AND HIS CONTRIBUTIONS :-
Samuel Hahnemann (1755-1843) was a physician of the 18th century medicine. Spinoza, Neuton, Harvey and Leuwenhoek’s best work of 17th century gave a deep source of original inspiration and some attempts to reveal the marvels of nature to many people of the day. Though there was certain advancement in the medical profession, yet on the question ‘life’ there were controversies amongst the physicians and theologians.
George Ernst Stahl (1660-1734) tried to reconcile the view of both the parties by his theory, Anima. To him, the soul and body were closely blended and the source of vital movement was the soul or anima. Latter on Joseph Barthez (1734-1806) proclaimed his idea of vital principle. Still later John Brown (1735-88), who was closely associated with Cullen, classified all diseases as sthenic or asthenic and advocated large and heroic stimulating drugs. Hahnemann being a physician of the best training of that day, followed in his early career, the footsteps of his predecessors.
Even after, Hahnemann saw the fruitful effects and light of law of cure, he continued to use massive doses. In 1786, one of Hahnemann’s earliest works namely, “On the Nature and Treatment of Venereal Disease”, long before he had any notion of a general therapeutic rule for employment of remedies in diseases, long before his peculiar pharmaceutical process of potentisation, he advocated giving enormous and repeated doses of Mercury. For Lues Venerea he gave one grain of soluble Mercury and for severe syphilis not more than total eight grains. To him, large doses were—half a grain, of one, two, three grains of mercury and for common employment quarter, third, half, three-quarters, and one grain.
In 1796, that is to say six years after his experiment with Cinchona bark, which led to the discovery of homoeopathic law, it was found that he was prescribing Arnica root in powder for dysentery. For children of four years of age he gave at first 4 grains daily, then 7, 8 and 9 grains daily, for children of six to seven years, he started with 6 grains, gradually increasing the dose to 12 to 14 grains, for a child of 9 months the doses was first 2 grains which was later increased to 6 grains. Three grains of Veratrum album every morning for 4 weeks was the dose he prescribed and with which he cured a case severe spasmodic asthma. [6,7, 8]
In 1797 (Lesser Writings, p. 353) he prescribed Veratrum album for a colic in doses of 4 grains once a day. From an another essay (Ibid, p. 369) that his doses were—Ipecacuanha—5 grains, Nux vomica 4 grain, twice a day, Cinchona bark-in dram doses. But in his essay “On the Cure and Prevention of Scarlet Fever” published in 1801 which had referred to his method of treatment of the year 1799 where we have the first indication of the “infinitesimal posology” which is now looked upon as an essential part of the homoeopathic system. [8, 9,11]
For the cure of the first stage of scarlet fever, the dose of Belladonna prescribed was only the 432,000th part of a grain of the extract, a quantity intermediate between our 2nd and 3rd dilutions. For prophylactic purposes, the preparation of Belladonna used was thus made: A grain of the powdered extract was mixed up in a mortar with one hundred drops of distilled water, three hundred drops of diluted alcohol were then added, and the whole well shaken up in a bottle. One drop of this strong solution was added to three hundred drops of diluted alcohol and shaken for a minute, and of this one drop was added to two hundred drops of alcohol, and this again shaken for a minute.
Each drop of this last solution, which is the prophylactic preparation contains accordingly the twenty-four millionth part of a grain of extract of Belladonna; accordingly, twenty four drops of it are equal to one drop of the 3rd dilutions of the so-called centesimal scale.
Thus gradually Hahnemann diminished the quantity of doses in a method known as potentisation and came to the conclusion that doses must be smallest as possible.
In an essay “The Spirit of Homoeopathic Doctrine,” first published in 1813, he stated that the smallest dose is sufficient and that a greater one not necessary because the spiritual power of the medicinal dose not in this instance accomplish its object by means of quantity but by quality or dynamic fitness and a larger dose does not cure the disease better but leaves behind it a complex medicinal disease. In 1814, he recommended Bryonia alba and Rhus toxicodendron in 12th dilutions for an epidemic of typhus. In 1819, on the treatment of suicidal mania the doses of gold were 6x. In 1821, for the treatment of purpura miliaris he recommended Aconitum napellus in 24th dilution. [12,13]
Thus between the year 1825 to 1827 we find a revolutionary change on Hahnemann’s posology. In the 4th volume of Materia Medica Pura published in 1826, Thuja occidentalis, Spigelia anthelmia and Staphysagria where directed to be used in 30th dilution. Hahnemann after his promulgation of psora theory fixed upon the 30th dilution of the centesimal scale as the appropriate dilution for every remedy and one globule, no bigger than a poppy seed imbibed with this dilution as the most appropriate dose. [14, 15]
His object in selecting such a minute dose was partly founded on his notion that the smallest quantity of the medicine was more than a match for the disease, and partly, as he tells us in the fourth edition of the Organon of Medicine, to diminish the action of the medicine as much as possible and at length it convinced him that these very minute doses were the most appropriate and at the same time he denies the utility of large doses and stated that he never had obtained the curative effect of the medicine until he arrived at this diminution of the dose. In the last years of his life he again allowed himself a greater range of dose, chiefly by extending the scale of dilution upward as high as 60th, 150th and even 300th dilution but also downward to the 24th and occasionally much lower. 
So, in homoeopathy, for healing purpose no medicine nor remedy is administered in a physiological or massive dose.
GUIDELINES OF MASTER HAHNEMANN REGARDING SELECTION OF DOSES:
A well selected remedy may fail utterly if the selection of the doses is not proper. It is very important as even a carefully selected remedy may fail if the potency is not correct. Master Hahnemann suggested the factors for selection of doses. Factors responsible for the selection of potency are:
• The susceptibility.
• The seat of the disease.
• The nature and intensity of the disease.
• Stage and duration of the disease.
• Previous treatment. [17, 18]
- SUSCEPTIBILITY OF THE PATIENT
It is a very important guide for the selection of a potency. Generally, more the susceptibility, lesser is the medicinal quantity, hence higher the potency. Factors determining the susceptibility are:
Susceptibility is maximum in a child and it decreases gradually as age progresses to youth and then at an increased pace till death, as it has to fight the catabolism of advancing age. It is nil in a dead person.
- Temperament and constitution
According to Dr Stuart Close give high potencies to:
– Sensitive individuals having a nervous, sanguine or choleric temperament.
– Intellectual persons who are quick to act and react.
– Zealous and impulsive persons.
According to Dr Stuart Close give low potency in repeated doses:
– Sluggish, coarse fibered individuals having gross habits.
– Torpid, phlegmatic persons who are slow to act and dull to comprehend.
– Persons possessing great muscular power which requires a power stimulus to excite them.
According to Dr E. Wright, medium potencies are best suited to:
– Oversensitive patients, who prove any medicine given to them. They, hence require medium low potencies.
– Idiosyncratic patients. In extreme cases of idiosyncracy, medium potencies are preferred.
c. Habit and environment
Give high potencies to:
– Those having an intellectual occupation.
– Persons who suffer from bad effect of excitement from imagination and emotions.
– Those who have sedentary occupations.
– Persons who sleep long or lead an effeminate life.
Give lower potencies to:
– Those having occupation which involves a lot of physical labour and being outdoors.
– Those who eat coarse food.
– Adapted to persons who get little sleep.
– Those who are connected to or are continually exposed to liquor and tobacco trade.
– People associated with drugs, perfumes and chemicals.
– Those who are idiotic, imbecile, and deaf and dumb.
Inter terminal cases where gross pathological conditions are present material doses or low potency drugs should be given. A dynamic medicine will not act here.
- THE SEAT OF THE DISEASE :-
Depending on the organ affected, the potency of the medicine is determined, i.e. the more important the organ and greater the organic pathology, the more material will be the dose.
- THE NATURE AND INTENSITY OF THE DISEASE :-
• Functional diseases with subjective symptoms respond well to high potencies, whereas organic conditions respond to lower potencies better. • In acute disease, the susceptibility is generally high as they are temporary in nature and do not involve much organic changes.
• In an acute paroxysm of chronic disease, medium or low potencies are preferable.
• Chronic diseases:
– With no organic change: It is safe to begin with the 200th potency, unless it is precarious because of the nature of the remedy and the depth of the miasm.
– With organic change: Lower potencies preferable.
- STAGE AND DURATION OF THE DISEASE :-
• In incurable chronic diseases, lower and medium potencies are preferable.
• In terminal stages of chronic diseases, very high potencies are preferred.
- PREVIOUS TREATMENT :-
Higher potencies are used in cases where there is a history of an increased intake of many crude drugs (allopathic or homoeopathic). The question of how much quantity of drug is required, may be said that it is the inverse ratio of the similarity. It may be said in other words— the finer, more peculiar and more characteristic symptoms or the remedy appear in a case, the higher the degree of susceptibility and the higher the potency and the decisive amount is always a minimum and an infinitesimal. 
The homoeopathic cure is obtained without any other suffering or drug symptoms by minimum dose. Homoeopaths prefer small doses because when a similar homoeopathic drug is administered in a disease, little or no resistance is encountered (i.e. no organic resistance). The homoeopathic drug acts in a manner similar to the action of disease producing cause itself. The homoeopathic dose is made so small that it does not produce any pathogenetic symptoms or severe aggravation of the already existing symptoms. The homoeopathic drug is given singly and also in small doses, because its action will be complete and unmodified by other drugs.
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ABOUT THE AUTHOR :-
Dr Vaidehi Bhatt, MD (Hom),
Department of homoeopathic pharmacy,
Rajkot Homoeopathic medical college,
Parul University, Rajkot.