PMHNP Psychopharm Exam 15 2024
What routes of med admin are parenteral - All Injections ( IM Sub Q IV, Intrathecal), AND
Inhaled , transdermal (patches) , transmucosal (sublingual, nasal, rectal) . All PO meds =
enteral; Topical is all ointments placed on the skin
PO meds absorption pattern - Varies greatly due to:
»»Stability and solubility of the medication
»»Gastrointestinal pH and emptying time
»»Presence of food in the stomach or intestines
»»Other medications currently being administered
»»Forms of medications (enteric-coated pills, liquids)
Rectal medication admin is? - Unreliable/ inconsistent absorption/ good for unconscious,
vomiting pts or small children
parenteral = - any route of administration other than oral or rectal ; injections, irrigation
solutions, dialysis solutions
Pharmacokinetics - What the body does to drug/ how it processes it.
The process by which drugs are absorbed, distributed within the body, metabolized, and
excreted.
factors that impact drug absorption - Body Factors: Area of absorptive surface i.e. in GI the
microfolds increase surface area, gut pH level, GI motility, presence of other substances.
other diseases; In elderly less acidic stomach ph and less blood flow to GI. Drug Factors:
Formulation , molecular size , lipid water solubility, concentration etc.
Pharmacodynamics - = study of what a drug does to body relationship between drug
concentration @ site of action and resulting effect, including time course and intensity of
therapeutic and adverse effects. The effect of a drug present at site of action is determined by
that drug's binding with a receptor. Receptors may be present on neurons in central nervous
system (i.e., opiate receptors) to depress pain sensation, on cardiac muscle to affect intensity
of contraction, or even within bacteria to disrupt maintenance of bacterial cell wall
Pharmacology - distribution - = process by which drug passes from bloodstream to body
tissues and organs .The following factors influence drug distribution: · Lipophilicity:
Lipophilic drugs pass through cell membrane/dissolves much easier vs hydrophilic.
· Drugs are redistributed in organs according to their fat and protein content.
· Most psychotropic medications are lipophilic and highly protein-bound.
-Only unbound (free) portion of drug is active. Therefore, people with low protein (albumin)
levels, such as in malnutrition, wasting, or aging, can potentially experience toxicity.
- People with high fat-to-lean body mass ratio (as in older adults) will have erratic amounts of
active drug in their system.
· Membrane permeability: To enter an organ, drug must permeate all membranes that
separate it from site of drug admin. i.e benzodiazepines, (very lipophilic) readily cross gut
wall, capillary wall, and blood~brain barrier; THUS they distribute to brain rapidly and are
useful for treating anxiety and convulsions. In contrast, some ABX cannot penetrate blood
brain barrier so those meds cannot be used to treat infections in brain. The blood~placenta
