Chapter 2 Drug Sources and Dosage Forms PDF

Chapter 2 Drug Sources and Dosage Forms  Drug Names Chemical name – actual chemical makeup of drug; only one for each drug Generic name – also known as official or nonproprietary name; only one for each drug; shortened version of the chemical name Trade name(s)...

Chapter 2 Drug Sources and Dosage Forms  Drug Names Chemical name – actual chemical makeup of drug; only one for each drug Generic name – also known as official or nonproprietary name; only one for each drug; shortened version of the chemical name Trade name(s) – made by manufacturers, copyrighted; brand or proprietary names; used to market the drug, any drug may have dozens with similar ingredients  Drug Sources Plants Animals (including humans) Minerals or mineral products Synthetic sources (chemical substances) Engineered sources (investigational drugs)  Plant Sources Grouped according to their physical and chemical classifications: – Alkaloids (organic compounds; combined with acids to make salts) Examples: nicotine, morphine sulfate – Glycosides Example: digoxin, from digitalis, derived from foxglove plant)  Animal Sources Derived from animal body fluids and glands: – Enzymes (pancreatin, pepsin) – Hormones (thyroid hormone, insulin)  Mineral Sources From earth and soil used to prepare medications: – Iron – Potassium – Silver – Gold – Sodium chloride (table salt)  Synthetic Sources Also called “manufactured” because they are created artificially Sources: – Living organisms (organic substances) – Nonliving materials (inorganic substances)  Engineered Sources Newest area of drug origin Involves gene splicing or genetic engineering Examples: Growth hormones Cancer drugs Drugs used to treat HIV  Dosage Forms of Drugs Classified according to their physical state and chemical composition These may include: gases, liquids, solids, and semi-solids May change states (from solid to liquid, or from liquid to gas) May be soluble in water, alcohol, or other mixtures  Solid Drugs Tablets – compressed, powdered drugs & bulk-filling material under high pressure. They are intended to be swallowed or dissolved in the mouth or in water or even chewed and absorbed through the GI tract. Can come in different sizes, shapes, colors, simple manufacturing process but can’t be swallowed easily by children and some adults. Pills – single dose unit of medicine made of a mix of powdered drug with liquid; rolled into a round or oval shape  Solid Drugs Plasters – compositions of liquid and powder that harden when dry (e.g. salicyclic acid plaster used to remove corns). Plasters may be solid or semi-solid. Easy to use, safe, effective but the adhesive may not adhere the plaster to the skin after long-term storage. Capsules – drug contained in an external shell usually made up of gelatin, these can enclose powder, granule, liquids or combination of these. Often used when medication have an unpleasant odor or taste. They can be pulled apart and added as a powder for individuals with difficulty swallowing. Solid Drugs  Solid Drugs Caplets – shaped like capsules but in form of tablets, the shape and film covering make swallowing easier. Gelcaps – oil-based medications enclosed in soft gelatin capsules, easy to swallow but difficult for water soluble material and can become degraded, highly sensitive to heat or humidity. Powders – drugs dried and ground into fine particles, stable, rapidly dissolved and absorbed but possibly bitter and could have dose inaccuracy.  Solid Drugs Granules – many small pills encased with gelatin capsules, usually found within capsules and are specially coated to release medication over a period of up to 12 hours. High stability, easy to use even in solutions. Troches or lozenges – flattened disks, hard or semi-solid dosage, intended for local application in the mouth or throat, usually left in the mouth until it dissolves, easily absorbed, may be perceived as candy leading to overdosage.  Semisolid Drugs These are often topical applications. Suppositories – bullet-shaped dosage forms for insertion into a body orifice and dissolve when inserted, easy to use and readily absorbed. Ointments – greasy medications intended for external application, usually by rubbing. Include some anti-inflammatory drugs, topical anesthetics, and antibiotics.  Semisolid Drugs Creams – (usually) white, nongreasy medications with a water base, often applied externally but may not stay on the skin as well as ointments. Gels – jelly-like substances for topical use, some have a high alcohol content and may cause stinging, nongreasy, may also produce a cooling sensation Semisolid Drugs  Liquid Drugs Drugs that have been dissolved or suspended and may be administered by mouth or injection Syrups – drug dosage form with a high concentration of sugar in water, can be quickly absorbed but may not be appropriate for all patients. Solutions – drugs dissolved in appropriate solvents, example saline Spirits – have alcohol, usually as a solvent and can dissolve substances less soluble in water Liquid Drugs  Liquid Drugs Liniments – drug mixtures of oil, soap, water, or alcohol, to be applied externally by rubbing, e.g used for treating muscle or joint pains Emulsions – combinations of two agents that are not usually combined, eg oil and water Mixtures and suspensions – an agent is mixed with a liquid but not dissolved, used for medicines with low solubility, need to shake well before use  Gaseous Drugs Pharmaceutical gases include the anesthetic gases: – Nitrous oxide – Halothane Compressed gases: – Oxygen for therapy – Carbon dioxide  Gaseous Drugs Advantages: targeted drug action and quick drug effects Disadvantages: volatility and potential for overdose Gaseous Drugs Drug Effects  Drug Effects Side Effect: drug effect other than the therapeutic effect that is usually undesirable but not harmful. Example: dry mouth, drowsiness Adverse Effect: general term for undesirable and potentially harmful drug effect. Example: persistent diarrhea, vomiting, or with prolonged use may affect kidney or liver. Toxic Effect: undesirable drug effect that implies drug poisoning, can be very harmful or life threatening.