HINTS ON PRESCRIPTION WRITING 51 



the amount or better by writing after it the abbreviation Q.E. 

 (Quantum Kectum). 



General Hints on Prescription Writing. The following hints 

 on prescription writing are taken from SoUmann : " When writing 

 a prescription for a given condition, put down, first, the name of the 

 best remedy. Ask yourself whether there is any other drug which 

 may be employed to aid or usefully modify this. Put this down 

 also. Then consider in which form the medicine should be admin- 

 istered, whether as liquid, powder, salve, etc. This will usually 

 determine which preparation of the ingredient is to be employed. 

 Put this down also. Then ask yourself what may be added to render 

 the mixture agreeable to the patient. When this is written, all the 

 ingredients will be represented. Now look over these carefully and 

 see that there are no incompatibilities and that the constituents are 

 soluble if the mixture is to be a liquid. Write the directions to the 

 dispenser. Assure yourself that the prescription is grammatically 

 correct, (especially the endings). Decide how many days the mix- 

 ture is to be taken and how many doses a day. Decide whether 

 the dose is to be a teaspoonful, tablespoonful, etc. By multiplying 

 the total number of doses with the size of the single dose, ascertain 

 the approximate size of the mixture. Round this off to a convenient 

 figure. See page 9. Multiply the single dose of each ingre- 

 dient by the total number of doses (again reducing the quantities to 

 round numbers unless the constituent is very active). Check the 

 doses. Write the directions to the patient (owner). Consider 

 whether a non-repetature is advisable. Affix your signature, the date, 

 and the name of the patient." 



The following prescription will illustrate the above. 



Single dose No. of doses Amount 



B Tincturae Aconiti in. xv x 8 3 ij 



Spiritus JStheris Nitrosi 5 ss x 8 3 iv 



Liquoris Ammonii Acetatis. . . 3 ss x 8 ^ i'^. 



Aquseq. s ad. 5 ij x 8 5 xvj 



In figuring the above prescription, we see that each dose of the 

 mixture will be slightly more than one ounce. The next handy dose 

 is two ounces. Consequently we decide upon that amount as the 

 dose and add sufiicient water (vehicle) to make eight two ounce doses. 



In dispensing extemporaneous preparations about the same rea- 

 soning is used, except that the ingredients are mixed as you decide 

 upon the remedies, instead of writing the names on paper. Of 

 course, in every day practice the multiplication of single doses is 

 carried out mentally and the product only written down. 



The name of each ingredient is written upon a separate line and 

 all important words are capitalized. The abbreviations and symbols 

 mentioned under weights and measures, page 7, are used for the 



