1. A number of drugs have been used for centuries, either as remedies or in religious ceremonies. Describe how three of these drugs were used by ancient civilization and how they are used today. Include in your answer the improvements made on these drugs.
From the ancient history, drugs have been widely used and the physicians acted as religious leaders due to their phenomenal skills to cure the ill. In the Chinese society, Ma Huang has been publically used for coughs, influence and fevers. In the modern era, this drug is renowned as ephedrine and has been questioned for its side-effects resulting even death.
Ephedrine became a highly popular and effective treatment for asthma. From mainstream medicine, ephedrine moved into the twilight zone of street drugs and nutritional supplements.
Ephedra and ephedrine products are now banned in many countries, as they are a major source for the production of the addictive compound methamphetamine. Compared from the previous era, Ma Huang can now be obtained in nonprescription forms. Capsules containing ma huang can now be achieved in a hydrochloride or sulfate salt form.
Moreover, current researchers have agree to the fact that the stem of ma huang is much safer for medical purposes than its alkaloid extracts compare to using the entire plant in the ancient Chinese history.
In the ancient Greek times, opium has been used and it has been generally used for pain relief as it contains morphine. Morphine is valuable due to its effect to relieve anxiety for usage on patients prior to operation. In order to enhance its ability, morphine could be converted to heroin. However, the risk of drug abuse and its dependence is much higher compare to morphine which isolates heroin in the field of pharmacology.
Additionally, opium also contained codeine which is one of the key elements for Tylenol. In Spain, Persia and Mesopotamia period, Colchicum has been used for gout. In the current society, the chemical colchicine is extracted from colchicum and still is a predominant drug for treating gout. Compared from the previous years, the public are able to access different types of drugs from a local store. One of the main issues from the colchicum is the unknown reaction of dosing different types of drugs at a single time which creates adverse effects for the patient.
2. Describe the concept of selective toxicity. Use the sulfonamides as an example. Selective toxicity is the ability of a chemical to kill a microorganism without harming its host. Penicillin is a bacterium with rigid cell walls to protect its high internal pressure. It is closely related to a chemical component that is needed to form new bacterial cell walls, known as D-alanyl-D-alanine. Therefore, it can prevent new bacterial cell wall formation, so as a result the cells are formed without cell walls. These are called protoplasts, which can readily burst.
However, cell walls do not exist within human cells. Therefore, it is not affected by penicillin, meaning it is selectively toxic to bacteria. Co-trimexazole is an agent with two components, sulfamethoxazole (a member of the sulfonamide group) and trimethoprim.
These two components are needed to produce a constant synergic antibacterial affect. These two components are contributed in the mechanism of action (metabolic pathway) needed for normal bacterial growth. Tetrahydrofolic acid needs to be formed for normal growth, since it is essential for DNA and protein synthesis.
Sulfamethoxazole (a member of the sulfonamide group) competitively inhibits para-aminobenzoic incorporation into dihydrofolic acid. This means that sulfamethoxazole is selectively toxic because by inhibiting the para-aminobenzoic incorporation, it destroys the microorganism without harming its host. This means that sulfonamides are selectively toxic.
3. Describe the four mechanisms (types) of adverse drug reactions. There are four core mechanisms of adverse drug reactions, extension of therapeutic effect, effect that are unrelated to its main symptom, Idiosyncrasy and finally drug allergy.
Over dose is one of the most crucial issues to concern for physicians. For example, in usage of benzdiazephine, overdose will result in over-sedation. Overdose of anticoagulant will inevitably lead to bleeding which is normally used for preventing clot formation. “All substances are poisons. There is none which is not a poison. The right dose differentiates a poison and a remedy. ” The equilibrium of its dose is the key of avoiding overdose adverse effect. Many of drugs used have side-effects that are recognized and not recognized.
Side-effects could occur unrelated to the purpose of its drug use. For example, digitalis group of drugs are generally used to strengthen heart muscle to cure patients with heart diseases. Regardless of its purpose, many of the patients suffer from nausea, vomiting, and abnormal colour vision. Physicians should be aware of the side-effects of the drugs prior to prescription. Every one of us unique which defines the fact that drug effects would not be exactly identical to everyone. Influence of succinylcholine is known to relax the tension of the muscle.
However, there are patients who have insufficient numbers of enzyme which inactivates the drug which excessively lengthen the period of the drug. Finally, drug allergy is also one of the different types of adverse effects of drug use. As antigens are produced on first drug use, it combines with the antibodies which often provokes an adverse reaction to patient leading to drug allergy. As patients are unaware of their own drug allergy, physicians should be aware of any circumstances that could happen.