Current Medicinal Drugs PDF

Current Medicinal Drugs 10.1- What are Medicinal Drugs? Medicinal drugs are substances used for treating diseases or relieving pain. Drugs come from several sources: - Some are synthesized (aspirin) - Some are obtained by fermentation or by microbiological cultures (antibiotics such as peni...

Current Medicinal Drugs 10.1- What are Medicinal Drugs? Medicinal drugs are substances used for treating diseases or relieving pain. Drugs come from several sources: - Some are synthesized (aspirin) - Some are obtained by fermentation or by microbiological cultures (antibiotics such as penicillin) - Others are obtained through extraction form animal sources (insulin and hormones) or plants sources - A drug is considered effective if it is nontoxic and if it as no side effects such as an allergic reaction or diarrhea. The effectiveness of a drug should not be diminished by substances present In human body, such as gastric acid. 10.2- Drug formulations and drug additives Drugs can be formulated and classified according to their shape into tables, capsules, liquids, sprays, ointments, suppositories… Composition: In general drugs are composed of active ingredient and inert ingredients. The inert ingredients are drug additives. For example, when a drug is formulated into a tablet, inert ingredients such as filters, binders Coating lubricants and disintegrator are added, which contribute to the tablet size, shape… 10.3- Characteristics of some currently used drugs Drugs maybe classified according to their channel structure or pharmaceutical activity (action in the body). 10.4 – Analgesics  Definition: Analgesics are substances that reduce or eliminate pain.  Classes: Analgesics are divided into three groups: a) Narcotic, which are used to reduce or eliminate moderate pain, morphine and codeine are the prototype. b) Anti-pyretic, which are used to lower or eliminate fever. c) Anti-rheumatics, which are used to reduce or eliminate inflammation of the muscles and the joints. Generic name (original) Trade name Pharmaceutical action Analgesic, anti-pyretic and anti- Aspirin Aspirin rheumatic Paracetamol or acetaminophen Panadol Tylenol Analgesic and anti-pyretic Aspirin: a) Aspirin is an effective pain reliever; its active ingredient is acetylsalicylic acid. b) Side effects: it causes severe damage to the stomach leading to significant bleeding. To avoid these side effects, alternative drugs (mild on the stomach) is taken such as Panadol and Tylenol.  Generic name: it’s the name of the active ingredient given according to the world health organization (WHO). 10.5 Anesthetics: Anesthetics are substances that produce anesthesia, a state of being unable to feel pain, heat, cold… Anesthetics are classified into local anesthetics and general anesthetics. a) Local anesthetics: - Used to provide temporary pain relief on localized regions of the body. - The act directly on nerve cell to block their ability to transmit impulses down their axons. - Local anesthetics are used for minor surgery such as in dentistry. - One of the oldest local anesthetics used by injection is cocaine ethyl chloride is an example of local anesthetics used as spray. b) General anesthetics: - General anesthetic, agent is reversible depressants of the central nervous system that produce the loss of sensation and consciousness. - General anesthetics are classified into inhaled and intravenous (administrated by injection). - Diethyl ether: inhaled anesthetics. - Penthiobarbital: intravenous anesthetics. - Side effect: An overdose of general anesthetics may lead to coma and death. 10.6 Anti-Acids: Anti-Acids are substances used to treat problems caused by excessive gastric acid, HCl. They contain basic active ingredients such as sodium bicarbonate NaHCO3, Mg(OH)2, CaCO3 … Anti-acids are weak bases that neutralize the excess of gastric acid. HCO-3 + H+ → H2CO3 → CO2 + H2O HO- + H+ → H2O Brand name Active ingredient Maalox Magnesium hydroxide and aluminum hydroxide Milk of magnesia Magnesium hydroxide Rennie Calcium carbonate and magnesium carbonate Effervescent antacid: It consists of a mixture of sodium bicarbonate and cirri acid or tartaric acid. “When this drug is dissolved in water the acid and base react to give CO2 gas producing the bubbling and effervescent action”. 10.7- Anti-inflammatory drugs Is a substance that reduces or eliminate inflammation. Inflammation is the reaction of tissues to injuries; it affects the connective tissues, and constitutes a reaction of defense of the organism against external aggressions. Anti-inflammatory agents can be divided into two main group: - Steroidal anti-inflammatory agents (substances with structure based on steroid nucleus). - Non-steroidal inflammatory agents. Salicylates such as aspirin, salsalate and dicloflenac are often used to treat arthritis… An overdose of aspirin is often characterized by marked increase in respiratory rate. Cortisone, hydrocortisone… are examples of steroidal anti-inflammatory drugs. The side effects of steroidal anti-inflammatory drug include fluid retention, unwanted hair, excessive weight… An overdose of cortisone may lead to overweight and obesity. Nonsteroidal anti inflammatory drugs: Generic name Trade name Possible side effects Aspirin Aspirin Stomach distress and nausea Ibuprofen Advil Nausea, vomiting, diarrhea… Dicloflenac Voltarene // // // 10.8- Antibiotics Defn: antibiotics are chemicals by one microorganism (natural antibiotics) or by chemical synthesis to kill or inhibit the growth of other microorganisms. Types: Antibiotics that kill bacteria are called bactericidal those that kill fungi are called fungicidal - Examples of commonly used antibiotics include penicillin such as benzyl penicillin (penicillin G), Sulfadiazine, streptomycin… - An overdose of penicillin (penicillin G) sulfadiazine, streptomycin dizziness, and intense contractions in the heart muscles. Side effect: Diarrhea is frequent side effect of antibiotic theory. A- Classification: Antibiotics can be classified into broad spectrum and narrow spectrum antibiotics.  Broad spectrum antibiotics are effective against wide variety of microorganisms (invading microorganisms is unknown).  Narrow spectrum antibiotics are effective against specific microorganisms (when the invading microorganisms are known). Note: the use of broad spectrum antibiotics should be restricted because they might kill some beneficial bacteria such as the intestinal flora. B- Bacteria resistant to antibiotics: - A bacterium that cannot any more be eradicated by the antibiotic, is called a resistant bacteria. It is usually the result of genetic modifications. - Bacteria resistance to antibiotics can be natural or acquired. Mechanisms of Bacteria resistance: Some resistance bacteria have the capacity to enzymes which modify or break the molecules of the antibiotics, and render it inactive. The bacteria are capable of growing in the presence of the modified antibiotics. C- Combination of antibiotics: Physician often use combination of two or three anti-biotic:  In case of emergency when the invading microorganism is unknown.  To treat mixed infection  To obtain a more intensive effect  To prevent emergences of resistant bacteria  To permit the use of a lower dose of the antibiotics Sometimes the combination of two antibiotics is considered a poor strategy because the two antibiotics may be antagonistic toward one another. 10.9- Tranquillizers: Tranquillizers are substances used to sedate without including or causing asleep. They are used to relieve anxiety, excitement, and restlessness. - Anxieties can be classified into normal and pathological. - Benzodiazepines such as diazepam and chlorodiazeppoxide are among the most prescribed drugs. Generic name Trade name Overdose effect State of intoxication Diazepam Valium (drunkenness), drowsiness, coma Chlorodiazepoxide Librium Muscle rigidity, coma and death. Side effects: (especially in the case of over dose) - State of intoxication (drunkenness) - Drowsiness - Coma and even death 11.0- Anti-depressants: Definition: Anti-depressants are drugs for treating depression. Typical symptom of depression includes: - Continuous sadness, loss of interest and pleasure including activities. - Barbiturates such as phenol barbital secobarbital (segonal) are the most prescribed antidepressants. The possible overdose effects…coma…death.