Pharmacology Need To Knows
Drugs in use today come from three main sources: natural sources, chemical synthesis, and biotechnology.
Natural sources include plants, animals, and minerals.
Examples of current drugs made from plants include atropine from the roots of the belladonna plant (Atropa belladonna; deadly nightshade), digitalis from the leaves of the purple foxglove, and morphine from the seeds of the opium poppy.
Animals provide a source for some drugs, particularly hormones.
Drugs derived from hogs are porcine.
Drugs derived from cattle are bovine.
Gold is used, as in aurothrioglucose (Solganal), an anti-arthritic agent.
Synthetic drugs are drugs that are synthesized from laboratory chemicals. Semisynthetic drugs are drugs that start with a natural substance that is extracted, purified, and altered by chemical processes.
The term biotechnology is used to refer to the concepts of genetic engineering and recombinant DNA technology.
Biotechnology is a process that allows scientist to produce proteins from bacteria.
Among the drugs produced by biotechnology are human insulin (Humulin), human growth hormone (Nutropin), human thyroid-stimulating hormone (Thyrogen), and the thrombolytic agent altepase (Activase).
Drugs such as these are always administered by injection; they cannot be taken orally because they are proteins, which are digested when consumed.
Therapeutic-action subcategories of drugs frequently used from the sterile back table include antibiotics, anticoagulants, anti-inflammatory agents, and local anesthetics.
Drugs are also classified by how they may be obtained. The distinction between prescription and non-prescription or over the counter (OTC) drugs is a legal classification.
Prescriptions must include the date, name of the patient, name of the drug, dosage, route of administration, and frequency or time of administration. It must also bear the prescriber's signature.

A standing order, or protocol, is used for common situations requiring a standard treatment.
A standing order of this type informs the operating room team that the indicated medication should be ready on the sterile back table as a standard part of the setup for that procedure.
Verbal orders are commonplace in surgery, as a surgeon may request a particular drug to be administered either from the sterile field or by the anesthesia provider.
Often given verbally,STAT orders indicate that a drug is to be administered immediately and one time only.
Drugs may be in solid, semisolid, liquid, or gas form. The form of drug administered affects both the onset of drug actions and the intensity of the body's response to the drug. gtts-drops susp-suspension ung-ointment Many drugs come prepared in solid form. These drugs may be in capsule (cap) or tablet (tab) form and administered orally.
Such powders must be mixed with a liquid (reconstituted) to form a solution that can be administered by injection.
Lidocaine (Xylocaine) jelly for topical anesthesia, Silvadene cream for burns, estrogen cream for vaginal packing, and neosporin ointment for wound dressing.
A solution is a mixture of drug particles (called the solute) fully dissolved in a liquid medium (called a solvent such as water or saline).
A suspension is a form in which solid undissolved particles float (are suspended) in a liquid.
Just before handling a medication in suspension to the surgeon, simply roll the syringe or vial between your fingers or palms to mix the suspended particles evenly.
Another type of liquid medication form is an emulsion, in which the medication is contained in a mixture of water and oil bound together with an emulsifier.
The most common emulsion used in surgery is propofol (Diprivan), an intravenous sedative-hypnotic agent is used for anesthesia.
The only common medications available in gas form are inhalation anesthetic agents.
In addition to the drug form, the route by which a drug is given can affect onset time and body response.
The three major categories of medication administration routes are enteral, topical, and parenteral.
The term parenteral indicates any route other than digestive tract.
The study of pharmacokinetics focuses on how the body processes the drugs, and the science of pharmacodynamics examines how the action of the drug affects the body.
Four basic physiological processes: absorption, distribution, biotransformation, and excretion.
Absorption is the process by which a drug is taken into the body and moves from the site of administration into the blood.
Drugs are absorbed from the site of administration into the bloodstream and enter systemic circulation.
Solubility of the drug (its ability to be dissolved).
Absorption of a medication depends on the formulation of the drug, the route of administration.
Once a drug has been absorbed into the bloodstream, it is transported throughout the body by the circulatory system.
The term bioavailability indicates the degree to which the drug molecule reaches the site of action to exert its effects.
The only drug molecules available to exert effects on the body are unbound molecules.
The extent of plasma protein binding can prolong a drugs effects and contribute to drug-drug interactions.
In the liver, the chemical composition of a drug is changed by a process called metabolism or biotransformation.
Only unbound (bioactive) drug molecules can be biotransformed.
Many drugs undergo a first-pass effect, which means they may be altered or nearly inactivated when passing through the liver, potentially reducing the drug's effectiveness.
Medications taken into the body are eliminated in the process called excretion.
Only drug molecules not bound to plasma proteins (that is bioactivemolecules) will be filtered out of blood plasma reaching the glomerus.
Four processes of pharmacokinetics
Administration - body systems varies by administration route, integumentary, gastrointestinal, respitory.
Distribution – circulatory system
Biotransformation – liver
Excretion – kidney
Drugs also may have more than one effect on the body and this is taken into consideration when prescribing medications.