1. Prescription and Drug Prescription Writing.
Department of Pharmacology & Toxicology
Medical University – Sofia
Dr Rumen Nikolov, PhD
Introduction to Pharmacology.
Prescription and Drug Prescription Writing.

2. Etymologically, pharmacology is the science of drugs (Greek pharmakon, medicine or drug; and logos, study)  
Pharmacology is a branch of medicine which deals with drugs.
Pharmacology can be defined as the study of the selective biologic activity of drugs in living matter.

3. A drug is a chemical substance that affects processes in living organism and
used for treatment, prophylaxis (prevention) or diagnosis of the diseases.
Classification of drugs:
OTC (Over-the-counter) drugs - drugs that do not require a prescription.
Prescription drugs - prescription drugs generally have a greater potential for adverse effects than OTC drugs, require monitoring for interactions with other medications, should only be used for a restricted time period.

4. Sources of drugs
Natural – plants, microorganisms, animals, minerals.
Synthetic
Semi-synthetic
Biosynthetic

5. Natural drugs
Plants
e.g. Morphine from Poppy capsules.
Atropine from Belladonna roots.
Digoxine from Digitalis leafs.
Quinine from Cinchona bark.
Hypericin and hyperforin from Hypericum herb.
Flavone glycosides and terpenoids from Gingko leafs.
Castor oil from Castor seeds.

6. Papaver somniferum
(Opium Poppy)
morphine
codeine

7. Atropa Belladonna
(Deadly nightshade)
Atropine

8. Digitalis lanata
Digitalis purpurea

9. Cinchona tree
Quinine

10. Hypericum perforatum
(St. John’s wort)
Esbericum caps.
Remotiv tab.

11. Ricinus communis
(Castor been)

12. Ginkgo biloba (maidenhair tree)
Flavonoids
Diterpene lactones

13. Natural drugs
Microorganisms
e.g. Penicillin from Penicillium notatum.
Streptomycin from Streptomyces griseus.
Gentamicin from Micromonospora purpurea.
Vancomycin from Streptococcus orientalis.
Minerals
e.g. Calcium, Magnesium, Aluminium salts.
Liquid paraffin from petroleum.

14. Natural drugs
Animals
e.g. Thyroxine from porcine or bovine thyroid gland.
Heparin from porcine gut or bovine lung.
Insulin from porcine or bovine pancreas.
Omega-3 fatty acids from
fish oil (Omacor).

15. Synthetic drugs (60-65%)
- They are prepared by chemical synthesis.
Sulfonamides – e.g. Sulfamethoxazole, Sulfadioxine
Fluoroquinolones – e.g. Ciprofloxacin, Levofloxacin, Moxifloxacin
Salicylates – e.g. Acetylsalicylic acid
Barbiturates – e.g. Phenobarbital
Benzodiazepines – e.g. Diazepam, Bromazepam, Lorazepam
Acetaminophen (Paracetamol)
Isoniazid

16. Semi-synthetic drugs
They are prepared by chemical modification of natural drugs.
Ampicillin from Penicillin G
Dihydroergotamine from Ergotamine
Dehydroemetine from Emetine

17. Biosynthetic drugs
These drugs are prepared by cloning of human DNA into bacteria like E. coli. Technique is called Recombinant DNA technology or Genetic engineering.
Human insulins
Human Growth Hormones (Somatropin)
Human Interferons (alpha and beta)
Human tissue plasminogen activator (Alteplase, Reteplase)
Human Erythropoietin (Eprex)

18. Gene therapy
- It is the introduction of functional genetic material DNA into target cells top replace
or supplement defective genes. It imparts new function to cells.
Cancers
Alzheimer’s disease
Parkinson’s disease
Diabetes mellitus
Arterial Hypertension
Cystic fibrosis
Multiple sclerosis
Muscular dystrophy

19. Pharmacopoeia
An official book published by authorized institution in a country containing
description of commonly used drugs with their sources, properties, uses, doses,
purity and potency.
Drugs contained in pharmacopoeia are official drugs.
European pharmacopoeia (E.P.)
British pharmacopoeia (B.P.)
United States pharmacopoeia (U.S.P.)
Indian pharmacopoeia (I.P.)

21. Chemical name which is LONG, COMPLEX AND NOT USED CURRENTLY
Drug nomenclature
Chemical name which is LONG, COMPLEX AND NOT USED CURRENTLY
Nonproprietary name (some times called ”generic name”) – given by WHO
official names (in pharmacopoeias)
approved names (not yet in pharmacopoeias)
Proprietary name (trade or brand name) - given by the manufacturer
e.g.
Nonproprietary name: Omeprazole
Brand names: Losec (AstraZeneca), Sopral (Sopharma), Probitor (Sandoz), Omeprazid (Nobel Pharma),
Ulcoprol (Actavis), Helicid (Zentiva)

22. 1,3 dimethylxanthine
Nonproprietary name : Theophylline
Тrade name: Novphyllin

23. Prescription
The prescription is a written order from
a doctor to a chemist including instructions for dispensing or preparing medicines to a certain patient.
It is require that the prescriptions in
Bulgaria should be in Latin.
The prescription order may be issued by physicians or other licensed medical practitioners and dentists.

24. Type of prescription forms
White Prescription form
Yellow Prescription form
Green Prescription form
Prescription form №5

25. Doctors use a white
prescription form to prescribed drugs without abuse potential.

26. Doctors use a yellow
form to prescribed drugs with high abuse potential
such as opioids (e.g.
morphine, methadone, fentanyl, pethidine).

27. Doctors use a green form to prescribed drugs with low abuse potential than opioids such as benzodiazepines (e.g. Diazepam), and barbiturates (e.g. Phenobarbital)

28. Doctors use a prescription
form №5 to prescribed drugs,
which are fully or partially
paid by the National Health
Insurance Fund.

29. Structure of the prescription
The prescription consists of seven parts including
1. Inscriptio
2. Praepositio
3. Praescriptio
4. Subscriptio
5. Signatura
6. Nomen medici
7. Nomen aegroti

30. Inscriptio
This part consists identification data such as name of the doctor, master degree of the doctor, address, and the date.
e.g.
Dr. I. Ivanov, dermatologist
“Alexandrovska” Hospital
Sofia,

31. Praepositio
This part includes message to the pharmacist which express with Rp. or Rp/, an abbreviation for Latin word Recipe (Take thou).
Rp. or Rp/
Doctor must write new Rp. for each new prescription

32. Praescriptio
Rp/……… …
Name
(Genetivus case)
Dose

33. The strength of the drug should be written in
metric units.
1,0
0,1
0,01
0,001
0,0001
1 g
100 mg
10 mg
1 mg

34. Subscriptio
This part is intended direction to the pharmacist. Doctor writes the number of the drug packing and the drug dosage form.
e.g.
Da scatulam №2 in tabulettis
or short form
D. scat. №2 in tab. or
Da tales doses №20 in tabulettis
D. t. d. №20 in tab.

35. Signa. Take one tablet 3 times daily. or short form
Signatura (Label)
This part is intended direction to the patient. It provides instructions for the manner of the use of the prescribed drug (how the drug should be taken by the patient).
e.g.
Signa. Take one tablet 3 times daily.
or short form
S. Take one tablet 3 times daily.

36. Nomen medici
Signature and seal of the doctor may be put at the marked place in the prescription blank or after the last prescribed drug.
Nomen aegroti
This part of the prescription includes name, home address, and age of the patient.

37. Symbols and abbreviations used in the prescription
 symbol for divided one prescription from next prescribed drugs
e.g.
Rp/ Paracetamoli 500 mg
D. sat. № 1 in tab.
S. Take 1 tablet 3 times daily. #
Rp/ Amoxicillini 1 g
S. Take 1 tablet every 8 h.

38. Symbols and abbreviations used in the
prescription
aa (ana partes aequales) is used to
expressing substances in equal quantities
ad is used to expressing add to get the
whole weight (volume) of the solution or
“up to”
q.s. (quantum satis) means sufficient
quantity.
M.D.S. means Mix, give and label.
M.f. (Misce fiat) means Mix to obtain.
Verte! is used when doctor writes on the back of the prescription blank.