Prescription and Drug prescription Writing

1. 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

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6. 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.

7. Papaver somniferum
(Opium Poppy)
morphine
codeine

8. Atropa Belladonna
(Deadly nightshade)
Atropine

9. Digitalis lanata Digitalis purpurea

10. Cinchona tree
Quinine

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

12. Ricinus communis
(Castor been)

13. Ginkgo biloba (maidenhair tree)
Flavonoids
Diterpene lactones

14. 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.

15. 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).

16. 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

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

18. 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)

19. 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

20. 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.)

22. 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)

23. 1,3 dimethylxanthine
Nonproprietary name: Theophylline
Тrade name: Novphyllin

24. 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.

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

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

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

28. 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)

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

30. 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

31. 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, 16.09.2010

32. 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

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

34. 1,0
0,1
0,01
0,001
0,0001
1 g
100 mg
10 mg
1 mg
100 µg
The strength of the drug should be written in
metric units.

35. 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
or short form
D. t. d. №20 in tab.

36. 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.

37. 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.

38. 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
D. sat. № 1 in tab.
S. Take 1 tablet every 8 h.

39. 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.