pharmacology

the process by which a drug works on the body

drugs that interfere with the fxning of foreign cells such as miccroorganisms or neoplasms.

the ability of a drug to attack only those systems found in foreign cells

The study if absorption, distribution, metabolism(biotransformation) abd excretion of drugs

The amount of a drug that is needed to cause a therapuetic effect

what happens to a drug from the time it is introduced to the body until it reaches the circulation fluids and tissues

occurs across a concentraion gradient, drug moves from higher concentration to lower concentration, this process does not require any cellular energy, occurs more quickly if drug is small and soluble in water and in lipids, and has no electrical charge.

Uses cellular energy to move drug molecule across a cell membrane. This process is used to excrete drugs by kidney.

Used in drug excretion, this involves movement through pores in the cell membrane

The protal vein delivers absorbed molecules into the Liver, which immediately transforms most of the chemicals by a series of liver enzymes. These enzymes break the drug into metabolites, some of which are deactivated and excreted and others activated and cause effects on the body. Sometimes oral dosage is higher to take first passs effect into account.Injected drugs go through biotransformation similar but is also absorbed into the system and can reach reactive tissue before the liver.

Involves the movement of a drug to the bodys tissues. Things that can effect distribution are: Lipid solubility, and ionization, perfusion of reactive tissue. diabetic(decreased blood flow) vasoconstriction in an extremity.

Drugs that are highly lipid soluble are more likely to pass through the BBB. Almost all antibiotics are not lipid soluble.

The process byy which drugs are changed into new, less active chemicals. Liver: everything that is absorbed from the G tract first entersthe liver to be "treated". Phase I: involves oxidation, reduction, or hydrolysis of the drug via cytochrome P450 system of enzymes. Phase II: usually involves a conjugation rxn that makes the drug less polar and more readily excreted by kidneys

The prescence of a chemical that is metabilized by a particular system often increases the activity of that enzyme system.

The removal of a drug from the body. The skin, saliva, lungs, bilem and feces are some routes used to excrete. The kidneys play the most important part in the excretions. Kidney disfxn can lead to toxic levels of a drug.

The time it takes for the amount of a drug in the body to decrease to one half of the peak level it previously acheived.

weight, age, gender, genetics, drug tolerence, cumulation, Physiological (diurnal rhythm, electrolyte balance, acid base balance, hydration) Pathological factors (disease, hepatic dysfxn, vascular disorders, low blood pressure) Immunological (allergies), Psycological (placebo effect, Health beliefs, compliance) Environmental (Temp. Light, Noise)

undesired effects that may be unpleasant or even dangerous. Can occur for many reasons:overdosage, sensitivty to the drug, Drugs actions cause other actions in the body.

Extensions of the desired effect

effects that the drug causes in the body that are not related to the theraputic effect.

• involves an antibody that reacts with specific sites in the body to cause the release of chemicals, including histamine, that produce immediate rxnz, that can lead to respiratory distress and even respiratory arrest.
• Assessment: Hives rash difficulty breathingm Increased BP, dilated pupils, diaphoresis, increase HR respiratory arrest.

• this allergy involves antibodies that circulates in the blood and attack antigens (the drug) on the cell site. causing death to the cell
• Assessment: CBC showing damage to blood forming cells(decreased hematocrit, WBC, and platelets) liver fxn elevated liver enzymes, decreased renal fxn.

• This allergy involves antibodies that circulate in the blood and cause damage to various tissues buy depositing in blood vessels. This rxn may occur up to a week or more after exposure to the drug
• Assessment: itchy rash, high fever, swollen lymph nodes swollen and painful joints, edema of the face and limbs.

• This rxn occurs several hours after exposure and involves antibodies that are bound to specific white blood cells.
• Assessment:rash, hives, swollen joints(similar to poision ivy)

Drugs designed to act selectively on foreign organisms. Action:interfere with biosynthesis of the bacterial cell wall and/or prevent invading organisms from using substances essential to their growth and develpment, interfere with protein synthesis and cell division., alter permability of the cell membrane to allow essential cell compnents to leak out causing cell death.

• Develop resistence in many ways: microorganism produces sn enzyme that deactivates the antimicrobial drug.
• changes cellular permability to prevent drug from entering the cell, altering binding sites on the membrane or ribosomes, which no longer accept the drug.Produce a chemical that acts as an antagonist to the drug.
• Prevent resistence by: taking the right dose and for the allotted time frame.