LEC - 3 - Sources of Drugs Flashcards
The origins from which drugs are derived, including natural sources (plants, animals, microorganisms, and minerals), semi-synthetic, synthetic, and recombinant DNA technology.
Sources of Drugs
Natural Sources of Drugs:
Plants
Leaves
Flowers
Fruits
Seeds
Bark
Animals
Minerals
The oldest source of drugs, used empirically. Drugs are derived from leaves, seeds, flowers, roots, bark, etc.
Plants
Disadvantages for plants:
plant identification
climatic and social conditions
season of collection
storage conditions
Standardization
purity of active ingredients.
Examples of Medicinal Leaves:
Digitalis purpurea
Eucalyptus
Tobacco
Atropa belladonna
Source of digitoxin and digoxin (cardiac glycosides).
Digitalis purpurea:
Source of eucalyptus oil (used in cough syrups).
Eucalyptus:
Source of nicotine.
Tobacco:
Source of atropine.
Atropa belladonna:
Examples of Medicinal Flowers:
Poppy (Papaver somniferum)
Vinca rosea
Rose
Source of morphine (opioid).
Poppy (Papaver somniferum):
Source of vincristine and vinblastine (anti-neoplastic drugs).
Vinca rosea:
Source of rose water (used as a tonic).
Rose:
anti-neoplastic drugs
vincristine and vinblastine
Examples of Medicinal Fruits:
Senna pod
Calabar beans
Source of anthracene (purgative used for constipation).
Senna pod:
Source of physostigmine (cholinomimetic agent used in treating glaucoma and anticholinergic toxicity).
Calabar beans:
purgative used for constipation
anthracene
cholinomimetic agent used in treating glaucoma and anticholinergic toxicity
physostigmine
Examples of Medicinal Seeds:
Nux vomica
Castor oil seed
Source of strychnine (CNS stimulant).
Nux vomica
Source of castor oil.
Castor oil seed
CNS stimulant
strychnine
Examples of Medicinal Roots
Ipecacuanha
Rauwolfia serpentina
Source of emetine (used to induce vomiting and has amoebicidal properties).
Ipecacuanha
Source of reserpine (hypotensive agent used for hypertension
Rauwolfia serpentina
used to induce vomiting and has amoebicidal properties).
emetine
hypotensive agent used for hypertension
reserpine
Examples of Medicinal Bark:
Cinchona
Atropa belladonna
Hyoscyamus niger
Source of quinine and quinidine (antimalarial and antiarrhythmic drugs).
Cinchona
Source of atropine (anticholinergic).
Atropa belladonna
Source of hyoscine (anticholinergic).
Hyoscyamus niger
anticholinergics
atropine
hyoscine
Medicines derived from animals
gonadotropins
heparin
insulin
thyroid extract
Medicines derived from microorganisms
penicillin
streptomycin
tetracycline
chloramphenicol
erythromycin
Medicines derived from minerals
iron
calcium
magnesium
aluminum
sodium
potassium
sulfur
lithium
for treating iron deficiency anemia
iron
for syphilis
mercurial salts
as a supplement
zinc
as an antiseptic
iodine
for rheumatoid arthritis
gold salts
for antiseptic properties
fluorine
for anti-dandruff shampoos.
selenium
Drugs where the nucleus from a natural source is retained, but the chemical structure is altered. These are often complex, expensive, and derived from impure natural compounds
Semi-Synthetic Drugs
Examples of Semi-Synthetic Drugs
semi-synthetic human insulin from pork insulin, 6-aminopenicillanic acid from fungus
Drugs synthesized in pharmaceutical laboratories from organic, inorganic, or both types of compounds
Synthetic Drugs
Examples of Synthetic Drugs
chloroform
ether
nitrous oxide
chloral hydrate
antipyretics
sulphonamides
antihistamines
anticonvulsants
anti-anxiety drugs
A process involving gene cloning, where DNA is cleaved by enzyme restriction endonucleases, and the desired gene is coupled to rapidly replicating DNA (viral, bacterial, or plasmid).
Recombinant DNA Technology
Examples of Recombinant DNA Technology
human insulin
growth hormone
tissue plasminogen activator
vaccines
interferon
erythropoietin
interleukins
granulocyte-colony stimulating factor.
Advantages of Recombinant DNA Technology
Large quantities of drugs can be produced in pure form with less antigenicity.
Disadvantages of Recombinant DNA Technology
Requires a well-equipped laboratory, highly trained staff, and is a complex and complicated technique.