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Terms in this set (31)

think needle
IV: barriers no barriers to absorption because it is bypassed
--Absorption pattern: instantaneous and complete
--Advantages: rapid onset; control --> we have precise control over levels of drug in the blood; Permits use of large fluid volumes; permits use of irritant drugs--anticancer drugs for example are very chemically reactive, can cause local injury if present in high concentrations.
--Disadvantages: high cost, difficulty, and inconvenience; irreversible; risk of fluid overload, infection, and embolism; drug must be water soluble; embolism--> risk of a blood vessel blockage at a site distant from the point of administration (embolism), can be caused in several ways: insertion of IV needle can injure the venous wall, leading to formation of a thrombus. Embolism can result if the clot breaks loose and becomes lodged in another vessel. Second, injection of hypotonic or hypertonic fluids can destroy red blood cells; the debris from the cells can produce embolism; lastly, injection of drugs that are not fully dissolved can cause embolism(if the fluid is cloudy or contains particles, it is not dissolved)
--Perform IV injections slowly to reduce risk of toxicity to the CNS

IM: barriers--> capillary wall but drugs can pass through the spaces between with ease; no significant barrier to absorption
--Absorption pattern: determined by water solubility of the drug and blood flow to the site of injection; drugs that are highly soluble in water will be absorbed rapidly
--Advantages: used for parenteral administration of poorly soluble drugs (which can't be done through IV); used to administer depot preparations (preparations from which the drug is absorbed slowly over an extended time)—the effects of a single injection may persist for days, weeks, or even months
--Disadvantages: discomfort and inconvenience can cause local tissue injury and possible nerve damage ; bleeding risk (can't be used for patients receiving anticoagulant therapy)

Subcutaneous: nearly identical to IM