1. Rational prescribing & prescription writing
Lab 19
Rational prescribing & prescription writing

2. Written prescription: is the prescriber's order to prepare or dispense a specific treatment- usually medication- for a specific patient.

3. Drug: Any substance or product that is used or intended to be used to modify or explore physiological systems or pathological states for the benefit of the recipient. They are used in 3 principle ways 1- curative as primary therapy. e.g. bacterial infection 2- suppressive of disease e.g. hypertension 3- preventive e.g. malaria

4. Names of drugs: 1- full chemical name
2- non proprietary name ( official or approved name) used in pharmacopoeias ( generic name e.g. barbiturates) .Advantages: clarity, economy& convenience
3- proprietary name or names that are commercial property of a pharmaceutical companies ( trade name) Advantages: quality esp. bioavailability

5. Elements of prescription
The elementary requirements of a prescription are that it should state what is to be given to whom and by whom. How much, how often ,by What route and sometimes for how long. 1-name of prescriber, address & office telephone number. 2- date on which the prescription written. 3- patient ś name, age, and address. 4- superscription- R ( Recipe) take thou. 5- inscription- the name and dose of the drug or drugs. The traditional prescription comprises: A- basis. The principle drug gives the prescription its chief action. B- adjuvant. A drug that aids or increases the action of the principle ingredient. C-corrective. Modifies or corrects undesirable effects of the basis or adjuvant. D- vehicle. Agent used as the solvent in the solution, to increase the bulk, or to dilute the mixture.

6. 6- subscription: directions to the pharmacist
6- subscription: directions to the pharmacist. Mix, make a solution, dispense. e.g. dispense 10 tab or 200 ml, make a solution, mix and make 10 caps. 7- transcription: instructions for the patient to be written on the container by the pharmacist. Label, mark. e.g. 1 tablespoonful 3 times daily, 1 cap twice daily. 8- signature. 9- refill, child proof container, warning.

7. Conversions between metric system & apothecary system. 1 grain (gr)= 0
Conversions between metric system & apothecary system. 1 grain (gr)= g ≈ 60 mg 15 gr ≈ 1g 1 ounce (oz)= 30 ml 1 teaspoonful= 5ml 1 tablespoonful= 15 ml 1 minim= 1 drop 20 drops= 1ml 2.2 pounds (1b)= 1Kg. 20%= 20 g/ dl

8. Abbreviations: ac before meals supp suppository
Aq water susp suspension
bid twice a day tab tablet
Cap capsule tid three times a day
g gram Tr tincture
gr grain prn when needed
h hour qs sufficient quantity
IA intraarterial stat at once
IM intramuscular µg microgram IV intravenous
OTC over the counter
Pc after meal
Po by mouth
PR per rectum
qid four times a day
Sc subcutaneous

9. Acute bronchitis
اسم الطبيب العنوان رقم الهاتف اسم المريض التاريخ العمر R 1- tetracycline 250 mg dispense 20 cap label : take one capsule four times daily. 2- paracetamol 500 mg dispense 15 tab label take one tablet three times daily signatures

10. Fungal infection
R benzoic acid 3.6g salicylic acid 1.8 g petrolatum to make 60 g make an ointment label apply a thin film to the affected part night & morning.

11. Painful myositis
Rx Aspirin 0.3 g Amobarbital 0.05g make 20 such doses & place in 20 cap label كبسوله واحده 3 مرات يوميا

12. Renal colic
Rx pot. citrate 2g sod. bicarb 2g conc. Infusion of buchu 2ml syrup of orange 4ml chloroform water up to 30 ml Mix and prepare 480 ml ملعقة طعام 3 مرات يوميا label