Drugs are obtained from various sources:
Plants contain biologically active substances and are the oldest source of drugs. Medicinal plants have been used for centuries in traditional systems of medicine across the world, including opium, belladonna, ephedra, cinchona, curare, foxglove, sarpagandha, and qinghaosu. Plant-derived active ingredients fall into several categories, including:
a. Alkaloids: alkaline nitrogenous bases that are potent and the most important category of vegetable-origin drugs. Examples include morphine, atropine, ephedrine, nicotine, ergotamine, reserpine, quinine, and vincristine.
b. Glycosides: compounds consisting of a heterocyclic nonsugar moiety linked to a sugar moiety through an ether linkage. Cardiac glycosides (digoxin, ouabain) and anthraquinone glycosides (active principle of senna and similar plant purgatives) are the best-known glycosidic drugs.
c. Oils: viscous, inflammable liquids that can be fixed (nonvolatile) or essential (volatile). Fixed oils are triglycerides of higher fatty acids used mostly for food and as emollients. Essential oils are aromatic terpene hydrocarbons used as flavoring agents, carminatives, counterirritants, and astringents.
Animal parts have been used as cures since ancient times, but it was not until the late 19th and early 20th centuries that the exploration of the activity of organ extracts led to the introduction of animal products into medicine. Examples include adrenaline, thyroxine, insulin, liver extract (vit. B12), antisera, and vaccines.
Most antibiotics come from fungi, actinomycetes, and bacteria, such as penicillin, gentamicin, tetracycline, erythromycin, polymyxin B, and actinomycin D. Enzymes such as diastase from a fungus and streptokinase from streptococci also have a microbial source.
A few minerals, such as iron salts, calcium salts, lithium carbonate, magnesium/aluminum hydroxide, and iodine, are used as medicinal substances.
Synthetic drugs are the largest source of medicines, producing drugs with purity and uniformity. Synthetic drugs can be manufactured in any quantity as per need, unlike drugs from natural sources, whose availability may be limited. Synthetic drugs include diverse congeners of naturally obtained drugs and entirely synthetic families of drugs, such as benzodiazepines, thiazides, benzimidazoles, and fluoroquinolones.
Peptides and proteins are now produced by recombinant DNA technology, such as human growth hormone, human insulin, alteplase, and interferon. Monoclonal antibodies and gene therapies are also being developed using biotechnology.
Disclaimer: This article is for informational purposes only and should not be taken as medical advice. Always consult with a healthcare professional before making any decisions related to medication or treatment.