Miranda Kelley, Victoria Tillotson, Madeline
Lisooey, Jacque Hargis
“ Drug absorption covers the progress of a drug from the time it’s
administered, through the time it passes to the tissues, until it becomes
available for use by the body.” (Lippincott, 2009)
There are two types of drug absorption, passive and active.
Passive transport: Requires no cellular energy. The drug simply moves from
an area of high concentration to an area of lower concentration. This is
called diffusion. Oral drugs are an example of passive transport.
Active transport: Requires cellular energy that moves the drug from lower
concentration to the higher concentration. This is used when the body is
absorbing electrolytes (potassium or sodium) or in the absorption of some
drugs. (Lippincott, 2009)
TYPES OF ABSORPTION
There are many different routes of administration, they consist of: buccal,
sublingual, translingual, gastric, intradermal, intramuscular, intravenous, oral,
rectal, vaginal, respiratory, subcutaneous, topical, epidural, intrapleural,
intraperitoneal, intraosseous, and intra-articular. (Lippincott, 2009)
ROUTES OF ADMINISTRATION
("A Drug's Life," A Drug's
Oral absorption is the most commonly used method when taking drugs. It is
cheap (no administration cost), there are no risks of fluid overload, infection,
or embolism. All of these things make the oral route the preferred route if
someone is going to self medicate. (Lippincott, 2009)
There are some disadvantages though too:
Barriers to absorption: the oral route of administration has two barriers when
it comes to absorption. The first is the layer of cells lining the GI and the
second is the capillary wall. (Lehne, 2013)
Variability : The drug absorption changes dramatically with each person.
Patient requirements : A person must be conscious and cooperative to be able
to administer a drug the PO route. If not alternatives must be considered.
The Intravenous route allows for injections of drugs or other substances (i.e.
blood products/fluid) directly into the bloodstream through a vein.
Barriers to absorption: NONE (absorption is bypassed) (Lehne, 2013)
Advantages: rapid onset, precise control over the amount of drug in the
bloodstream, can use large volumes of fluid. (Lehne, 2013)
Disadvantages: expensive, inconvenient, and irreversible (Lehne, 2013)
The intramuscular/subcutaneous route will allow for drugs to injected into
various depths of muscle groups. This accomplishes rapid systemic action and
can accommodate large doses. (Lippincott, 2009)
Barriers to absorption: capillary wall (no significant barrier to absorption)
Rate of Absorption: can be fast or slow depending on two variables. The
water solubility and and blood flow (Lehne, 2013)
Advantages: can be used parentally for poorly soluble drugs, and for depot
preparations (Lehne, 2013)
INTRAMUSCULAR (IM) /
(2012, Aug 17). Factors affecting absorption [Web Graphic]. Retrieved from
(2011, Oct 27). A Drug's Life [Print Photo]. Retrieved from
Lehne, R. (2013). Pharmacology for nursing care. (8th ed.). St. Louis: Elsevier.
Lippincott, W. &. W. (2009). Nursing pharmacology made incredibly easy!. (2nd ed.).
Ambler,PA: Lippincott Williams & Wilkins.