Pharm Test 1 Flashcards
Pharmacokinetics is
The study of how medications enter the body, reach their site of action, and eventually become eliminated.
Pharmacology is
The study of drugs and their actions on the body.
Absorption is
The PROCESS whereby a medication is moved from the SITE OF APPLICATION into the body and into the EXTRACELLULAR FLUID COMPARTMENT.
Distribution is
The PROCESS whereby medication is transported from the SITE OF ABSORPTION to the SITE OF ACTION.
Elements that can affect medication distribution are
Cardiovascular Function
Regional Blood Flow
Medication Storage Reservoirs
Physiological Barriers
When cardiac output is markedly diminished, some body areas are:
MINIMALLY PERFUSED, and medication delivery to these areas is NEGLIGIBLE.
In certain conditions, such a shock and congestive heart failure, cardiac output will fail. When it does, medication distribution becomes:
MUCH SLOWER and MUCH MORE UNPREDICTABLE
In cardiogenic shock, blood flow to the kidneys is often diminished. This means:
Meds acting specifically on the kidneys, such as diuretics, may not reach the kidneys in adequate concentration to be effective.
The action of medications binding to medication resevoir tissue proteins tends to:
DELAY THE ONSET OF ACTION and PROLONG ITS DURATION OF EFFECT
There are two types of storage reservoirs:
PLASMA reservoirs and TISSUE reservoirs.
The portion of medication that is bound to plasma proteins is called:
Bound Medication.
The portion of medication that is unbound within the vascular and lymphatic system is called:
Free Drug.
As soon as medication becomes bound to plasma carrier protein OR storage tissue protein:
It becomes INACTIVE.
When a medication becomes inactive:
It is rendered unavailable for binding to a RECEPTOR PROTEIN.
When a medication is unavailable for binding to a receptor protein:
It is incapable of exerting therapeutic activity.
In order to maintain a balance between the amounts of free and bound numbers, a medication:
Can RAPIDLY FREE ITSELF.
Only the Free or Unbound percentage of the medication remains
ACTIVE.
The DEGREE to which a medication is bound (to plasma proteins) is referred to as:
Binding Capacity
Binding of a medication to plasma proteins tends to:
Limit its concentration in the tissues
Common tissue reservoirs include:
The tissues of Fat, Bone, and Muscle.
As with plasma protein binding, tissue protein binding is usually
Reversible.
Quantitatively, muscle tissue represents:
Sizable medication reservoir.
Lipid (fat) soluble medications concentrate in:
The fatty tissues of the body.
Lipid soluble meds result in:
Prolonged medication effect.
Two physiological barriers to medication distribution are:
Blood Brain Barrier and Placental Barrier
What are some physical properties of the blood brain barrier?
- It’s a network of capillary endothelial cells with no pores.
- It’s surrounded by a sheath of glial connective tissue that makes impermeable to water-soluble medication.
What are some functional properties of the blood brain barrier?
- Protective mechanism of the brain.
- Effective/selective boundary between CNS/PNS
- Excludes most IONIZED meds (dopamine)
- Allows NONIONIZED UNBOUND meds (barbs.)
In order for meds to be delivered to a fetus through the placental barrier they must be
Nonionized, lipid soluble, unbound
Medications are eventually eliminated from the body in one of two forms:
Original form or Metabolite.
Excretion refers to
The movement of a med or its metabolite from
THE TISSUE –>BACK TO CIRCULATION–>EXCRETION ORGANS
Meds may be excreted by the following organs/substances:
KIDNEY/URINE LIVER/BILE INTESTINES/FECES LUNGS/AIR (sweat) (saliva) (breast milk)
Excretion through mammary glands becomes a concern when:
Mothers take medications while breastfeeding
Meds may be artificially removed from the body by direct interventions such as
Peritoneal dialysis
What’s the relationship between shock states and medication elimination?
During shock states, the kidneys are poorly perfused. Meds primarily eliminated by the kidneys remain present in the body for longer periods.
Elimination means
Substance Removal
Safety and TOXICITY are determined by
The INCIDENCE and SEVERITY or reported adverse reactions to the use of a drug.
Adverse reactions may not appear for a considerable time.
Safety and Toxicity are being refined constantly as past experiences illuminate deficiencies in the standard.
Toxicity is
The DEGREE and INCIDENCE to which a substance can damage an organism
Habituation is
Physical or Psychological dependence on a drug.
Synergism is
The combined action of two medications
The action is much stronger than the effect of either medication administered separately
“Antagonism” signifies
OPPOSITION
between 2 or more medicaitons
An agonist is
A substance
That binds with a specific receptor and
Causes a physiological response.
Delivery of medication to these areas of the body is generally much slower:
GI System
Skin
Muscles
Fat
