Writing A Drug Prescription

 A prescription should be

     *  A precise

      * Accurate

      * Clear

      * Readable set of instructions

      * Sufficient for a nurse to administer a drug accurately in hospital

      * Or for a pharmacist to provide a patient with both the correct drug

       *The instructions on how to take it.  

 Writing drug doses

  • Quantities of 1 gram or more should be written in grams. For example, write 2 g.
  • Quantities less than 1 gram but more than 1 milligram should be written in milligrams. For example, write 100 mg, not 0.1 g.
  • Quantities less than 1 milligram should be written in micrograms or nanograms as appropriate. Do not abbreviate micrograms or nanograms. For example, write 100 micrograms, not 0.1 mg, 100 μg, 100 mcg or 100 ug.
  • If a decimal point cannot be avoided for values less than 1, write a zero before it. For example, write 0.5 mL, not .5 mL.
  • For liquid medicines given orally the dose should be stated as the number of milligrams in either 5 mL or 10 mL of solution.

    Prescribing controlled drugs


 Because of the problems of drug addiction and misuse of drugs, in the UK drugs likely to be abused are the subject of the Misuse of Drugs Act (1971), the Misuse of Drugs (Notification of and Supply to Addicts) Regulations (1973) and the Misuse of Drugs Regulations (1985). Doctors in other countries should make themselves familiar with local regulations.


 Some abbreviations that are used in prescribing Other abbreviations should be avoided and instructions should be written in plain English whenever possible.

 Information to be given on a prescription outside hospital

v  The date

v  The patient’s name, initials and address

v  The age

v  The name of the drug, preferably in capitals (use generic names when possible)

v  The formulation to be prescribed

v  The strength of the formulation

v  The dose

v  The frequency of administration

v  The route of administration

v  The doctor’s name, address and signature

 How to write a prescription for a controlled drug


 ü  Complete the prescription in handwriting in ink

ü  Sign and date it

ü  Include your address

ü  Include the name and address of the patient

ü  State the form and strength (if appropriate) of the drug

ü  State the total quantity of the drug or the number of dose units to be dispensed in both words and figures

ü  State the exact size of each dose in both words and figures



 The purpose of drug therapy is to cure or ameliorate disease or to alleviate symptoms. However, all drugs have adverse effects and before a drug is prescribed clinicians need to weigh the potential benefit of therapy against the potential for doing harm. A good prescriber:

  • prescribes only when necessary, having carefully assessed the balance of benefit and harm
  • chooses medicines that are appropriate for the disease and the patient
  • chooses a dosage regimen that is appropriate to the disease and the patient
  • continues therapy for an appropriate time and alters doses when necessary.