tions. Rules for termittent, marsh miasmata, which he sees to be a debiPrescrip litated state of the system. This he learns is to be removed by tonics; and of those the bark of the cinchona officinalis is justly celebrated in the cure of intermittents. This then he would immediately prescribe; but that experience has shewn it to be better to begin the administration of this medicine as soon as possible after a paroxysm. We shall suppose, however, that the last paroxysm took place the day before he saw the patient, and consequently may be expected to return the next day. He finds also that the patient is costive, a circumstance which must be removed according to the third indication. Now, attending to the second indication, he knows that this is generally best fulfilled by the exhibition of an emetic at the commencement of the cold fit, and of an opiate at the commencement of the hot fit; but the costiveness of the patient contraindicating the use of opium, he must endeavour to find for it a substitute which has not a tendency to excite or increase constipation. He will perhaps prescribe as follows: Example of B. Vini ipecacuanha, unc. 1. prescription. 38 39 Arrangement of formule. 40 Tartritis antimonii (Edin.) unc. . M. fiat haustus. tions. in the prescription, this being considered as the guide by Rules for which the compounder is to direct his operations. Sup- Prescrip pose we were to prescribe a medicine containing castor oil, distilled water, mucilage of gum arabic, syrup of rhubarb, and tincture of senna. In the preparation of this medicine the apothecary will first rub together the oil and mucilage; he will then add the syrup, and perhaps the tincture, and lastly the water. In this order then it would be best to express the formula. See Kirby's Tables, formula 54. In this manner the neatness of the medicine is insured, and the preparation of it rendered more easy and expeditious. It is very usual for prescribers to begin with the article that is to be most abundant in the medicine, as the water, and so gradually descend to that of least quantity; and particular care is generally taken to place in succession those ingredients that are employed in equal quantities, with the sign (aa singulorum, of each) after the last. This seems rather a puerile method, and is commonly inconsistent with the practice of composition. There are other reasons for arranging the ingredients in the order of composition. In some cases a very volatile substance forms a part of the medicine, as æther, or ammonia; and it is proper that this should be the last Signetur. The emetic to be taken just as the next ingredient in the composition of the medicine, that as cold fit is coming on. B. Pulveris Rhei Palmati, gr. 25. Submuriatis Hydrargyri, gr. 3. Succi Spissati Hyoscyami, gr. 4. Syrupi q. s. Fiat bolus. little as possible of it may be dissipated. It is proper, therefore, that it should stand last in the formula (see Kirby's Tables, formulæ 126, 129, and 130.). There is a formula given in the Pharmacopoeia Chirurgica for an embrocation, to be composed of 2 drams of tincture of camphor (camphorated spirit), I dr. water of acetawater. We are told that the mixture of these ingredients is to take place in the order in which they are set down, otherwise the camphor will be separated *. Signetur. To be taken just as the next hot fit is ted litharge (Goulard's extract) and a pound of distilled coming on. B. Pulveris Cinchona officinalis, scr. 2. Croti Elutheria, gr. 10. M. f. pulvis. Signetur. One to be taken in a little wine and water as soon as the hot fit is gone off, and repeated every two hours till the expected return of the next cold fit. The analysis of this prescription will afford us some useful practical observations. 1. It will be observed that the formulæ are arranged in the order in which the medicines are to be exhibited, a circumstance to which it is always proper to attend, when the prescription is to contain more than one formula or circumstance to be directed by the practitioner. Thus when any thing is required immediately, as bleeding, the application of leeches, or of a blister, this should form the first clause in the prescription, in the following manner. Mittatur sanguis è brachio STATIM ad unc. 12.; or, Applicentur quamprimum temporibus hirudines sex; or, Applicetur statim emplastrum vesicatorium capite raso. Arrange- 2. The ingredients directed in each formula should be ment of in- arranged in the order in which they are to be mixed by gredients. the compounder. This may be thought a matter of slight importance, but it is more deserving of notice than is generally supposed. For the most part, indeed, in whatever order the practitioner may arrange the ingredients in his formula, a skilful apothecary will combine them in that order which experience has shewn him to be the most convenient; but it is surely much neater that the order of preparation should be preserved Pharm P. 159. We have already mentioned (N° 3) the names of Chr 5th edit. the several parts of which a compound medicine be may formed, as the basis, the adjuvant, the corrector, and constituent; and have explained the reasons for the addition of the three latter. There are some rules respecting these, which it will be proper to consider in this place. 41 3. The basis should always be single, unless some Rules for manifest advantage is expected to arise from the em- the basis; ployment of two or more remedies of the same kind. The reason of this rule is sufficiently obvious, as the effect of a single remedy is much more easily determined and proportioned than that of two or more employed together. The advantages of simplicity in prescription will be considered presently. 4. If more than one basis be employed, they should be of the same nature, or such as produce the same effects. This needs no illustration. 42 5. With respect to the adjuvant, we shall remark on-for the adly that one use generally assigned to it, viz. that of fa-juvant; cilitating the solution of the basis in the stomach, appears equivocal. It is not uncommon to order resinous drugs to be made up into pills with soap, which is considered by many as acting in the way of promoting so lution. Soap is often a good constituent, but we do not think it can produce the effect above alluded to. 43 6. The use of the corrector requires a little more dis- for the corcussion. One of the first intentions of the corrector isrector. to diminish the too violent action of the principal remedy, or to prevent its exerting an action in an improper part of the body. Thus, mucilage may be added to colocynth, tions. Rules for colocynth, (bitter apple), or given after it, to blunt Prescrip- or lessen the acrimony which this substance is commonly found to possess. So again, mercury is often combined with opium, when it is required to introduce a considerable quantity of the former into the system, or to speak more properly, to acquire the full benefit of its accumulated stimulus. This can scarcely be effected, if it be allowed to run off by the bowels. Camphor is often given after the application of a blister, to obviate the strangury which frequently attends the external application of cantharides. In some cases the cinchona bark produces sickness or purging, and here the addition of a few drops of tincture of opium to each dose is pro 44 Abuse of Cinctures. per. 7. Another use of the corrector is to obviate or disguise the unpleasant taste or odour of the principal remedy. Thus, the emetic in our prescription is ordered to be prepared of the wine of ipecacuanha instead of the powder, as the wine that forms the solvent of that remedy disguises its unpleasant taste. The articles usually employed as correctors of flavour, are syrups and tinctures of various kinds, essential aromatic oils, &c. and the use of these has been often much abused. The addition of a large quantity of sugar, in some cases, especially in dyspepsia or indigestion, seldom fails of increasing the symptoms of the disease, as in a debilitated state of the stomach it quickly passes into a state of fermentation, and produces flatulence, pain, and anorexia or loss of appetite, the very symptoms which we are to remove. It is a common practice to add syrup to several of the neutral salts, as sulphate of soda, sulphate of iron, &c. with a view to improve their flavour; but we apprehend that whoever has tasted the nauseous mixture will scarcely agree with the prescriber that he has gain ed his point. 8. The abuse of alcohol in the form of tinctures has been sometimes carried to a great, and, we think, a culpable excess. This has arisen sometimes from the desire of the patient to have his medicines made strong and good, and not unfrequently, perhaps, from mercenary views in the practitioner, to induce the patient to swallow a greater quantity of medicine, because it is rendered agreeable to his palate. We have no doubt that many well-meaning practitioners order a considerable dose of tincture from a mistaken complaisance to their patients, without apprehending any ill consequences from it; but in fact, the intemperate use of these tinctures is injurious to the stomach, and has, we believe, not unfrequently drawn some of the most sober persons into a habit of dram-drinking. The propensity to the use of cordials, which is now become so prevalent, has probably arisen from this source. The quantity of alcohol ordered by some prescribers is truly astonishing. A book lately came into our hands, which is called a translation of elegant medical prescriptions for various disorders by the late Dr Hugh Smith. For the accuracy of the translation we cannot vouch, not having seen the original; but if it be accurate, the spirituous cinna mon water (spirit of cinnamon), seems to have been a very favourite article in Dr Smith's catalogue of medicines, as it is no unusual thing to see an ounce, or ounce of it ordered in a single draught, or four ounces in an eight-ounce mixture. Did not this occur so frequently in the prescriptions of Dr Smith, we should suppose it to be some blunder of the translator or transcriber, VOL. XVII. Part I. t in mistaking the character denoting dram for the symbolical character signifying ounce. 9. A third use of the corrector is to render the medicine more agreeable to the stomach. Thus, sulphate of soda is to many persons very nauseous, and is not unfrequently rejected by vomiting; but the addition of a small quantity of lemon juice, or of supertartrate of potash, is found to correct this unpleasant quality. The bark of cinchona does not agree with some stomachs, without the addition of an aromatic; the cascarilla or dered in the above powders, affords a useful addition, with the view of rendering it more agreeable to the stomach. Rules for Prescriptions. 45 46 The unpleasant odour of a medicine is more difficult to correct than its flavour. In internal medicines this is usually best effected by regulating the form in which they are exhibited; as, in prescribing the sulphurate of potash, it is better to order it in the form of a powder to be sweetened with sugar, to be swallowed dry (see Kirby's Tables, formula 68), than by way of draught or mixture. The odour of external medicines is best corrected by the essential oils and perfumes. Thus, in using sulphur for cutaneous diseases, it is usual to add a quantity of essence of bergamot or oil of lavender, which, though they do not entirely destroy the odour of the sulphur, have a considerable effect in disguising it. 10. In ordering a corrector, the practitioner should Quantity be aware that it is not the quantity of the basis, but its of a remedy quality that he is to correct. If a dose of digitalis or plated. of squill makes the patient sick, we should not think of giving opium or effervescing draughts to prevent this effect, but we should lessen the quantity of the medicine at its next exhibition. We have been rather minute on the subject of the corrector, as we conceive that much will depend on the adroit management of this part of a formula, in showing the neatness and address of the prescriber. By a proper use of correctors he can often regulate the action of a medicine, and considerably relieve the feelings of his patient. 47 to be regu 48 stituent. 11. The constituent employed in a formula will of Remarks course vary with the form of the medicine. In the on the conmore solid compositions, as boluses, pills, and electua-* ries, it is generally syrup, conserve, confection or extract. In liquid medicines, it is either simple water, or some watery liquid, as decoctions, infusions, or water distilled from some aromatic plant. It is proper to remark, that the prescriber should consider whether a constituent ordered as such, be necessary, for it often happens, that the extracts or pilular masses kept in the shops, are already of a proper consistence for making into pills. It is obvious that the constituent, if it be not simple water, should have similar qualities with the other parts of the medicine, unless when it contains in it the corrector. 49 written at 12. In the prescription which we have given as an Names of example, the names of the articles are written at length. ingredients We do not, however, approve of this being generally need not be done in practice. To an apothecary's apprentice it can length. answer no other end than to exercise his latinity, and' display the erudition of the prescriber. In fact, it may even tend to mislead him; for as the names of the articles kept in his master's shop, are always painted on the labels, or drawers, in an abbreviated form, the words at full length are not better understood by the S s compounder, tions. Rules for compounder, and indeed they are often more intelligible Prescrip in the concise form in which he is accustomed to see them. Add to this, that the writing of the words at fall length may occasionally betray the practitioner into an unguarded mistake, which may call in question his grammatical accuracy. In Fox's Formule Selecta, calomelas perpetually occurs as the genitive instead of calomelanos; and in a work on midwifery, published by Dr Pugh of Chelmsford, grammatical errors both in the names and in the directions are to be detected passim. The only advantage that writing at length seems to possess, is that it teaches a beginner to read a prescription, which by the way is often at first no easy 50 matter. But practice soon renders this familiar. Symbolical characters to be avoided. 51 Rules for the doses of medicines. 13. The quantities of the ingredients in the above prescription are not expressed in the usual symbols, but we have employed the contracted forms of the words uncia and drachma, and the common Arabian figures, as recommended in the preface to Dr Kirby's Tables, The directions also are written in English. The reasons assigned in the work above referred to, are as follow. "The characters 3 and 3 are so similar, that they may easily be written for each other, and that they have sometimes been so written cannot be denied. The consequence is obvions; a stroke of the pen too much may kill the patient, and a stroke too little may produce a medicine of little or no efficacy. Strange! that physicians should have been so misled by an affectation of mystery or concealment, (for to what else can be attributed the use of these hieroglyphics)? as to place the safety of their patients at the mercy of a lapsus pennæ! Unc. and dr. can never be written for each other, and we see no good reason why these abbreviations should not be employed for uncia and drachma, as well as gr. and gtt. for granum and gutta. Dr Spens, in his elegant edition of the Pharmacopoeia Nosocomii Edinbur gensis, has employed these contracted words, but has retained the Roman numerals. "The use of the Arabian figures appears calculated to insure both perspicuity and dispatch. They are more easily written, occupy less room in a prescription, and (by their familiarity) remove all possibility of mis take. "As to the directions, they should always be written in the vernacular language. In a prescription, perspicuity is always our first object; it is not here that we are called upon to display our learning and classical elegance; and whoever considers that these are properties not always to be met with in the shop of an apothecary or a druggist, will readily wave them, in order to insure the perfect understanding of his prescriptions. It does not indeed require any great knowledge of Latin to translate the directions which usually occur in prescriptions; but as there are cases in which a long and rather complex direction is employed, we should leave nothing to the contingency of the learning or ignorance of the compounder, but by writing the directions ourselves in the received language of the country, put it out of his power to injure our reputation, or endanger the safety of the patient." The doses of medicines must, in a great measure, be determined by experience; but after having thus ascer tained the medium dose proper for an adult under ordinary circumstances, and of an ordinary constitution, there are certain general considerations, according to 52 14. The circumstances of the disease to be attended to Doses regu are its nature, seat, period, and degree of violence.lated by There are several diseases that require Herculean reme- the disease. dies, and these in very large doses. It is well known that maniacs require much greater doses to produce the same effect than most other patients. If we are to administer an emetic to a person in this situation, it would be of no use to prescribe 2 or 3 grains of tartrate of antimony and potash, or a scruple of ipecacuanha, the usual doses in ordinary cases. Less than 6 grs. of the former will scarcely excite vomiting, and it is sometimes necessary to order 10 or 15 grs. If we wish to procure sleep to these wretched beings, a few grains of opium are a trifle. Dr Darwin mentions two cases of insanity, in one of which 2 scruples of solid opium were administered, and four hours after, a third scruple; while in the other, a furious maniac was rendered calm and rational in the space of a few hours by a dose of 400 drops of tincture of opium. Again, the more violent the disease, the larger doses are generally required for its removal; but, on the other hand, the later the period or stages of several diseases, as fever, consumption, and similar affections attended with great debility, the less is the quantity required to produce the same effect; or rather the less able will the patient be to bear the usual doses. When the vital powers are much diminished, a large dose may be attended with very serious consequences. Thus, in cases of suspended animation by drowning, where the vital energy is nearly exhausted, if, when the powers of life are just returning, we were to oblige the patient to swallow a quantity of brandy, or even a glass of pure wine, we should probably smother the glimmering spark. Again, in cases of torpor from cold, if we expose the frozen limb to a sudden considerable heat, a gangrene ensues; whereas, had we in the former case given a little wine and water, and in the latter applied a moderate gradually increasing warmth, attended with gentle friction, we should probably have restored the patient, and preserved the limb. 53 ture and 15. The powers, form, and intention of the medicine. By the na must be considered. The more active remedies must be administered with greater caution than such as are of intention of inferior efficacy. Thus, if we are to exhibit the corrosive the medimuriate of mercury, the oxide of arsenic, the nitrate of cines. silver, or other powerful and dangerous remedies, we must begin with a quantity rather below than above the medium dose, and gradually increase it according to the effect produced. On the other hand, however, we must not descend to doses that are trifling and inert. It is as ridiculous to prescribe a scruple of cinchona twice or thrice a day, to restore vigour to a debilitated system, as it would be improper to order half an ounce of rhubarb for an ordinary cathartic. A prudent practitioner will avoid both extremes of timidity and rashness, and tions. Rules for will auither risk the safety of his patient by an excessive Prescrip dose, nor give him lingering suspense and pain, for want of the due application of the proper remedies. Much will depend on the form in which the medicine is to be exhibited. Thus, if we are to employ externally, or by way of blister, such medicines as are usually given by the mouth, it is necessary to order them in much larger quantity. The usual dose of tincture of opium is 25 or 30 drops; but if this is to be applied by friction, from 2 drams to half an ounce will sometimes be required for one application; and in a glyster it is usual to prescribe a dram or two. The tincture of cantharides, whether given internally, or applied by friction to the surface, is a powerful remedy; but in the former case, 20 or 30 drops are sufficient, while in the latter a dram or two is usually employed. Similar remarks might be made with respect to the use of mercury, and many other remedies. The intention with which the medicine is administered must also be taken into consideration, as there are many substances that produce different effects, according to the quantity employed. Thus, tartrate of antimony and potash may be given as an emetic, a diaphoretic, an expectorant, or a cathartic, according to the magnitude or repetition of the dose. Two or three grains given at once, or a grain every 15 minutes, usually excite vomiting; but from gr. to I gr. given every 5 or 6 hours, generally keeps up a constant nausea without vomiting, and thus, by sympathy, the medicine acts as a diaphoretic or antispasmodic. The medicine given in the dose of a third of a grain twice or thrice a-day is a good expectorant; and in the dose of gr. every two or three hours, usually operates by the bowels. It is well known that the effect of opium varies considerably, according to the dose and the interval at which it is administered. If we wish to promote sleep, or relieve pain, we give what is called a full dose, that is, a grain or two. It thus acts as a narcotic, and an antispasmodic or a diaphoretic. Given in small repeated doses, it acts as a general stimulus, promotes absorption, and an 54 of the patient. 16. We must regulate our doses according to the age, Age, &c. sex, constitution, and habits of the patient. It is evident that various ages must require various proportions; but experience shews that the required doses are not directly proportional to the ages, as might à priori be expected, and as the mathematical physicians in the beginning of the 18th century believed (B). Experience has enabled us to construct a table, in which may be shewn the doses proportioned to various ages, adjusted from a certain medium dose for an adult: such a table is the following. (B) At the time when Newton had by his discoveries rendered the study of mathematics as fashionable as it is useful, medicine partook of the general bias, and several physicians of ingenuity and erudition attempted to reduce its theory and practice under the dominion of their favourite science. Among these Dr Strother read and published a course of lectures on the rationale of medicines, which he entitles Prelectiones Physico-mathicæ et Medicopractica. In his 21st lecture he treats of the doses of medicine, and after discussing in a very philosophical manner the general mode of regulating these according to the size and shape of the particles of medicines, and their momentum as determined by their celerity multiplied by their quantity of matter, he proceeds to point out how we are to proportion the doses to various ages. He has the following question: If a person of 30 years of age takes 60 grains of any medicine, how much must a child of 5 years of age take? This question he of course resolves by the rule of proportion in the following manner. 55 Table. In order to render this generally applicable to every case, he calls in the aid of algebra, and substituting symbols for the above numbers we have the greater age given Then rat: · (~+ =). $82 Ru'es for tions. tion. 56 The above table may serve as a general guide to the Prescrip- young practitioner. The second column shows the aliquot parts of the medium dose for an adult, that are adapted to different ages from seven weeks to 100 years, Explana- supposing this medium dose to be 1; and the third column gives the absolute quantities in grains, &c. taking the medium dose at 1 dr. This table, however, will by no means apply in all cases. Thus, the dose of opium adjusted from this table, for a child of five years old, is gr. and that of submuriate of mercury or calomel, I gr.; but in cases of phrenitis hydrocephalica (water in the head), we may administer half a grain of the former, and three or four of the latter. Females in general require less doses than males; and persons of a robust and vigorous constitution, such as country labourers, the more active mechanics, servants, and those of the melancholic and phlegmatic temperaments, will, all other things being equal, require larger doses than persons of an opposite description. 57 Climate. 58 Idiosyncracy. The climate also seems to have some influence in this respect. In America and the West Indies we are informed that much larger doses of submuriate of mercury are given than are usually prescribed in Britain. In cases where we would give three or four grains, they would order 10 or 15. We are told, too, that in some parts of India, in order to excite vomiting in a native, it is sometimes necessary to give 20 scruples of ipecacuanha. The Germans, and especially, according to Gaubius, the inhabitants of Saxony and Westphalia, require much larger doses than the inhabitants of any other country in Europe. Peculiarities of constitution, commonly called idiosyncrasies, require attention on the part of the prescriber. It is therefore proper to inquire whether any circumstance of this kind occurs in any individual, especially when called for the first time. The habits of the patient must also be regarded, as in general medicines lose some of their effect by being often repeated, and therefore require to have their dose increased. Thus, persons who are accustomed to the use of opium, will derive no benefit from the ordinary doses of that medicine, but when labouring under a complaint that requires the exhibition of opium, they must take a quantity somewhat larger than that to which they tions. are habituated. It is well known what quantities of Rules for tion. 59 17. Perspicuity is essentially necessary in writing a Perspicuity, prescription, and every thing which can in any degree a principal diminish it ought to be carefully avoided. Many of the considera observations already made have been directed to this point; and we have yet one or two remarks to complete this part of our subject. A prescriber should be very careful not to introduce into his prescription articles which are obsolete, or which are no longer contained in our pharmacopoeias, unless he is certain that the apothecary who is to prepare the medicine keeps such articles beside him; and even then, as it is most likely that they have been long prepared, and have lost much of their efficacy, he cannot depend on their answering the end he proposes. Thus, few would now think of prescribing the confectio paulina, the theriaca Andromachi, or the aqua alexiteria simplex, or many other compounds, which have given place to more simple and convenient forms. 60 cines to be 18. The same cautions will apply, though perhaps Obsolete with some limitations, to those medicines which are or uncom rarely met with, or have been newly introduced into mon mediour Pharmacopoeias. Before we venture to prescribe an ordered article of this description, we should ascertain whether with canor not it is to be procured in or near the place where tion. the patient resides, or, where possible, we should give timely notice to the apothecary to provide himself with some of it. Many unpleasant circumstances may arise from not attending to this caution, especially where the patient is apprised that he is about to take a new remedy which has been found very beneficial in cases similar to his own. For instance, the Rus Toxicodendron has lately been much extolled in the cure of palsy. Suppose a physician in a provincial town, at a great distance from the capital, were to prescribe this medicine. The apothecary has none of it, nay, perhaps, has never ver heard of the medicine, and it must be procured from the capital. This occasions a delay for several days, and in the mean time the paralytic person is impatient to try the effect of the new remedy, and probably refuses to take any other. When the medicine arrives, the (c) Before dismissing the subject of the Doses of Medicine, we must notice an improvement lately proposed, and which appears likely to be adopted by the London College in the intended new edition of their Pharmacopœia, we mean that of abolishing the usual method of measuring small doses or quantities of liquids by drops. There can be no doubt that in many cases this method of dropping liquids is liable to great uncertainty; the size of the drops, and of course the quantity of liquid which they contain, varying greatly according to the nature of the liquid, the size and form of the neck of the phial from which they are let fall, and even the state of the atmosphere. The dram, by measure, of distilled water, will afford only 60 drops from an ordinary two ounce phial with a neck of the usual diameter; whereas the same bulk of proof spirit may be divided into 120 drops, and some tinctures will afford many more. Considering this uncertainty, it is proposed to abolish the very name of drops (gutt.) in prescriptions, and to employ the small graduated measures of Lane, in which the dram is divided into 60 equal parts, which may be called grains. Thus, instead of ordering gutt. 30 of tinct. opii, we shall order gr. 15. (ƒiƒteen grains) or 4 of a dram, allowing for the difference between water and spirit. This will certainly be an improvement where moderate doses are to be prescribed, but when the dose does not exceed two or three drops, as in some of the essential oils, arseniate of potash, &c. so much would be lost in the measure that the dose would be rendered very uncertain. On the whole, we would recommend that in all cases the medicine shall be so diluted that the dose shall not be less than half a dram, and spoons might be made for family use that should contain that quantity, as an ordinary tea-spoon now contains a dram. |