PharmacologyPharmacology is the study of the actions of drugs on the body and the way the body metabolizes drugs. The study of pharmacology includes the biochemical action on the body by drug and incorporates the knowledge and ideas from other scientific disciplines like biology, chemistry and physiology.

In this section of the course, we will cover dosage forms and administration, pharmacology itself, pharmacodynamics and a quick overview of body systems like the cardiovascular system, skin, and endocrine systems

Source of DrugsNatural Sources of Drugs

Drugs that originate from plants or animalsExamples:

Acetylsalicylic acid (ASA or Aspirin) originates from the bark of the willow tree.

Cocaine originates from the coca plant (Erythroxylum coca) Morphine and Codeine originate from the Papaver somnifera plant Digoxin comes from the Foxglove plant Vincristine and Vinblastine are called vinca alkaloids and come

from the periwinkle plant. Niacin is a B vitamin (B3) is found in green vegetables Cyanocobalamine is a B vitamin (B12) found in eggplant and meats Insulin was originally isolated from pork (porcine) or bovine (cow)

pancreas

Unusual Sources of drugsLepirudin (Refludan®) is an anticoagulant that is

used in hospital to treat PE and DVT. Source: ?The saliva of leeches known as Hirudo medicinalis.

A leech is a blood sucking wormPremarin® is conjugated estrogens used to treat

vaginal bleeding and to treat post menopausal Sx in middle aged women. Source:?

The urine of pregnant maresCaptopril is an ACE inhibitor used to treat

hypertension and CHF. Source:?Brazilian arrowhead viper: a poisonous snake

Synthetic Drug SourcesMost synthetic drugs are really semi-

synthetic in that the drug is chemically modified from a natural source.

Examples are:Oxycodone (Oxycontin®)Succinylcholine (Quelicin®)Piperacillin/Tazobactam (Zosyn®)Amoxicillin (Amoxil®)

Genetically Engineered Drugs Recombinant DNA technology is a new modality that arised in the late 1970’s

and early 1980’s. Greatly accelerated by the Human Genome Program completion in the late 1990’s.

Involves sequencing the gene for a human protein, carrying a vector for that gene (usually a virus), have the vector infect a host (usually a bacteria, E. Coli) and allowing the bacteria to mass produce the gene product for us to market.

Examples: Recombinant human insulin . Recombinant insulin has almost completely

replaced insulin obtained from animal sources (e.g. pigs and cattle) for the treatment of insulin-dependent diabetes ]

Recombinant human growth hormone. (HGH, somatotropin). Growth hormone is administered to patients whose are growth hormone deficient.

Recombinant blood clotting factor VIII. Recombinant factor VIII is a blood-clotting protein that is administered to patients with hemophilia

Recombinant hepatitis B vaccine. Prevention of hepatitis B infection is controlled through the use of a recombinant hepatitis B vaccine, which contains a form of the hepatitis B virus surface antigen that is produced in yeast cells.

Drug NomenclatureChemical name: the name of a drug

according to its chemical structure. Generic Name: the name given to a drug in

agreement with the originally manufacturer and the FDA. Also called the nonproprietary name

Trade Name: the trademark name given to a drug by the original manufacturer. It is also called the proprietary name. No other manufacturer can legally use this name for their version of the drug

The Five Rights of Medication AdministrationRight PatientRight DrugRight RouteRight DoseRight Time

Dosage FormulationsThe Dose formulation are different vehicles

for the same drug in which each type of formulation, or vehicle, provides certain advantages and disadvantages

Solid Dose FormsTablets

Tablets are a solid dosage form of drug in which the drug is mixed with various active ingredients that provide a convenient way to give the drug. For the most part the inactive ingredient impart stability, color, taste, and bulk to the dose form

Advantages are: stability, convenience, and masking bad taste

Disadvantages are: difficulty in swallowing is taken orally, slow to act in the body

Tablets can be manufactured to be chewable, effervescent, enteric coated, or made into a controlled release dosage form

Some examples of different tablets types are:Chewable vitamins and aspirin for adultsEnteric coated aspirin (Ecotrin®), Depakote ®, Videx EC

(didanosine), Nexium®, Protonix ®, and Voltaren® EC. Enteric coated drugs are coated to protect either the stomach from the drug or the drug from the stomach.

Effervescent drugs most commonly release carbon dioxide. Example : Alkaseltzer®

Controlled release dosage forms where design to release the drug slowly over time in the GI tract. Examples: Toprol XL (metoprolol succinate), Tiazac ® CD (diltiazem CD), Calan® (verapamil CD), Procardia XL (nifedipine) and Glucotrol XL (glipizide). Controlled release dosage form should never be chewed!!

Route of administration for tablets can be orally, sublingually (Nitrostat®), buccally (Suboxone ®), and vaginally (Estrace®). Rectally administration is also possible

Capsule Dosage FormsCapsule have many of the same advantages

and disadvantages as tablets.One advantage over tablets is the gelatin

coating of the capsule is much easier to swallow that tablets

Ointments Mixture of a drug into a semisolid vehicle baseTypes of bases used: white petrolatum, lanolin, PEG

base, waxes, and hydrophilic petrolatumOleaginous ointments can be used to carry drug and

to be an emollientWater soluble ointments carry drug and can be easily

washed off is needed.In general, ointments that carry drug are more potent

than the cream version of the same drugLiniments are ointment that possess a chemical agent

that acts as a irritant. I.e. Methanol, camphor, etc

CreamsVehicles in which a drug is mixed into a

semisolid fluid medium.Creams are emulsions that are either water

in oil or oil in water based.More popular because they are not as greasy

as ointment basesLotion are similar to cream except water

concentrations are higher

Liquid Dosage FormsSolutions are aqueous mediums were the drug is completely

dissolved in water. The drug is called the solute and the water is the vehicle or called the solvent. Commonly used to deliver medications like oral solution, enemas, irrigation solutions, IV solutions and others

Suspensions are aqueous mediums where the drug is not completely dissolved in the medium but is “suspended” in the medium to produce a mixture that is homogenized upon shaking.

Viscous Solutions are mediums that are similar to suspensions in that the drug is suspended into the medium. Include Jellies and mucilages (Metamucil®). Magmas and milks are in this category

Syrups are viscous solutions that have a high concentration of sugar. Simple Syrup USP is 85% sucrose in water

Non Aqueous SolutionsHydroalcoholic solutions are a mixture of

water and alcohol.Elixir are mixture of alcohol, water, and sugar

and a least one active ingredient.The alcohol is meant to solubilize a drug that is

normally not soluble in water alone and also to prevent the crystallization of sugar and to act as a preservative

Examples are Digoxin Elixir and Donnatal Elixir

Pure Alcoholic SolutionsThese solution have only alcohol has the solventCollodions are alcohol mixtures containing alcohol (ethanol)

and pyroxylin (nitrocellulose)Collodions are made when cotton is dissolved in mixture of

sulfuric and nitric acid to produce nitrocellulose. The nitrocellulose is made soluble by mixing it in alcohol

Collodions are used to mix high concentration of ASA in the therapy of wart removal.

Also found in “liquid Bandages”Poisonous if swallowedSpirits have a high concentration of alcohol and solubilize

various organic oils that are volatile. Normally used as a flavorant (i.e. peppermint oil spirits)

ExtractivesExtractives are liquids that are hydroalcoholic or purely

alcohol solutions that contain a drug in high potency.The crude drug found in plants usually are macerated,

and pressed and dried. The material is exposed to an extractive which draws the active drug(s) into the extractive.

Tincture is a hydroalcoholic extractive of a drug where the potency of drug is equal to 100 mg of the crude ingredient per ml. i.e. Tincture of Opium 1 ml contains the equivalent of 10 mg morphine (this is how much morphine is in 100 mg of crude opium poppy)

Fluidextracts are 10x the potency of tinctures

Routes of Drug AdministrationPO= Per os (by mouth)IV= intravenouslyIM=intramuscularlyID=intradermallySubQ= subcutaneouslyINH= via inhalationPR=per rectum (inserted into the rectum)PV= vaginallyOpth=in the eyeOtic= in the earOften the following routes are written out with no

abbreviations: Intrathecal, Intraventricular, Intravesicular, and Intravitreal, Intraperitoneal, Intrapleural and Intra-arterial