Question | Answer |
What are some types of drug metabolism? | Accelerated drug excretion - active drug/metabolism/inactive drug
Drug inactivation - active drug/metabolism/inactive drug
Activation of prodrugs - inactive drug/metabolism/active drug |
What are the opioid receptors in the brain? | Mu - analgesic, respiratory depression, sedation, euphoria, dependence, decrease GI motility
Kappa - analgesic, sedation, decrease GI motility
Delta - opioids do not interact with these |
What are pure opioid agonists? | Morphine - strong
Codeine - moderate |
What is a pure opioid antagonist? | Blocks the opioid receptor site
Narcan (naloxone) is the prototype
Given when someone ODs on morphine and they will wake up, but morphine kicks it back down |
What are side effects of opioids? | Decreased respiratory rate
Oversedation
Nausea, vomiting
Hypotension
Constipation
Urinary retention |
How are drugs metabolized? | Liver is primary site of drug metabolism
Biotransformation
Enzymatic alteration of drug structure |
How is the therapeutic index calculated? | TI = LD/ED; want TI to be larger; more safe |
What is pharmacokinetics? | How the body affects drugs. |
What is Gate Control Theory? | Close-off pathway of pain to the brain.
i.e. rubbing a Charlie horse
Analgesics close the gate |
What is an opioid? | Natural or synthetic drug with similar action of morphine (prototype). |
What are opiates? | Compounds present in opium products. |
What is an agonist-antagonist opioid? | Talwin is the prototype
Blocks (antagonist) the Mu receptors and allows (agonist) the Kappa
Less potential for abuse
Less respiratory distress
Less analgesic effect |
Tolerance, Dependence, Addiction | Tolerance - decreasing drug effect over time
Dependence - physiologic symptoms when drug is discontinued (withdrawal)
Addiction - obsession with obtaining and using the drug |
ADRs of NSAIDs | GI bleeding
Altered drug metabolism - liver
Affect renal function; blocks prostaglandins
Take with food or glass of water
Do not chew or crush tablets |
What do prostaglandins do? | Promote inflammation
Protect gastric mucosa
Cause platelet aggregation
Maintain renal blood flow
COX-2 = protect inflammation; COX-1 are the other three |
First generation of NSAIDs | ASA
Ibuprofen
Naproxen
Toradol (IM)
Block both Cox-1 and Cox-2 |
Second generation NSAIDs | Block Cox-2
Celebrex
Only one left on market; rest pulled for causing cardiac arrhythmia |
Acetominophen (NSAID) | Not anti-inflammatory
Usage can lead to liver toxicity |
How can drugs be excreted? | Kidney - urine
GI - stool
Lungs - air |
What is pharmacodynamics? | The effect of drugs on the body (and how they do it) |
What effects can drugs have on the body? | Binding at receptor sites (agonist/antagonist)
Chemical reactions
Selective toxicity
Modify cell environment
Psychological effect
Therapeutic
ADRs
Allergic response |
What are common ADRs? | Cardiac arrhythmia
Blood dyscrasias (bleeding)
Hepatic toxicity
Renal damage
Ulceration of GI tract
Dermatologic
Ototoxicity
Sexual function |
What are properties of an ideal drug? | Effectiveness
Safety
Selective
Reversibility
Predictability
Ease of administration
Minimal ADRs |
What are some cognitive behavioral interventions? | Alters interpretation and perception of pain
Relaxation
Distraction
Imagery |
What are ways to interrupt the pain pathways? | Cutaneous stimulation
Cold application = ice
Massage
Acupuncture
Acupressure
TENS = electrical stimulation device |
What occurs in the four phases of clinical drug trials? | Phase I - how the drug is metabolized; few subjects
Phase II - therapeutic effects; more subject with disease
Phase III - dosages; even more subjects with disease
Phase IV - find more side effects on general population; post-marketing surveillance |
What is the goal of drug therapy? | Maximum benefit with minimal harm |
Concentration (of drug) at the site of action is influenced by what? | Absorption - rate of
Distribution - efficiency of
Metabolism
Excretion |
What can affect distribution? | First by-pass effect - liver metabolizes some of drug
Blood flow to tissues
Ability of drug to exit vessels and enter circulatory system
Tissue binding - drugs like fat tissue |
What is distribution? | Getting the medication to the site where it needs to go.
It has to get into the circulatory system. |
What does parenteral mean? | Outside of the GI tract
IM, SubQ, IV, Intradermal (TB test)
Topical - sublingual, dermal, rectal, vaginal, inhalation |
What does enteral mean? | Through the GI tract; orally |
What is absorption? | How much and how fast the drug leaves the site of administration and is delivered into the circulatory system. |
What are the first three scheduled drugs that came from the Controlled Substance Act of 1970? | Schedule I - nonresearch use banned (i.e. heroin)
Schedule II - need to be written on a special prescription pad; usually narcotic in nature; no telephone orders; i.e. Ritalin
Schedule III - need to be reordered every 6 months; antidepressants |
What are the last two scheduled drugs that came from the Controlled Substance Act of 1970? | Schedule IV - penalties vary if caught in possession
Schedule V - not prescription, but need to go to pharmacy to obtain (i.e. drugs used to make methamphetamine) |
What is a drug? | A chemical that is capable of interacting with a living organism to produce a biologic effect. |
What are risk factors for fluid volume excess (FVE)? | Hypervolemia
Increased fluid intake
Decreased output - renal failure, decreased cardiac output
Symptoms: Weight gain, bounding pulses, peripheral edema, rales with auscultation |
What are risk factors for fluid volume deficit (FVD)? | Hypovolemia - dehydrated - sunken eyes, cracked tongue
Age - infants and elderly become dehydrated easily
Increased fluid loss - GI distress; flu, vomit, diarrhea
Decreased intake |
What lab values can be used to assess fluid balance? | BUN (8-20 mg/dL) - higher values indicate possible kidney issues; comes from breakdown of protein
Creatinin (0.6 - 1.3 mg/dL) - higher values are better indicator of kidney problems
Hematocrit - less solvent increases solute concentration |
What two hormones regulate kidney function? | ADH (anti-diuretic hormone) and aldosterone
ADH results in retaining water, and thus retaining sodium ion
Aldosterone results in retaining sodium ion, and thus water (renin-angiotensin loop)
Results in increased BP |
What is the distribution of body fluids? | 75% ICF
25% ECF - 20% in the interstitial spaces and 5% in the vessels
Some people look "wet" but they have low BP; sign that excess fluid is in the interstitial spaces (the third space) |
What are some uses for cholinergic blockers (anticholinergics? | Used for overactive bladder
Combat diarrhea
Dramamine - motion sickness
Dilate pupils at optometrist
Given prior to surgical procedures to decrease oral secretions |
What are organ effects with sympathetic stimulation? (adrenergics) | Cardiac - increase HR
Respiratory - dilate
Bladder - no affect
Colon - no affect
Eyes - dilate
Arteries - vasoconstrict |
What are organ effects with parasympathetic stimulation? (cholinergics) | Cardiac - slows HR
Respiratory - contraction
Bladder - increase activity
Colon - increase activity
Eyes - constrict
Arteries - vasodilate |
What are side effects of anticholinergics? | Can't see, spit, shit or pee |
What are the target organs of anticholinergics (cholinergic antagonists)? | Cardiac - mild increase in HR
Respiratory - mild bronchial dilator
Mucus membrane - decreased secretions (xerostomia = dry mouth)
Colon - decrease motility
Ocular - dilate pupils |
What are ADRs of cholinergic agents? | Frequent urination
Diarrhea
Blurred distance vision (from constriction)
Diaphoresis |
What are the target organs of parasympathetic cholinergic agents? | Cardiac - slows HR
Colon - stimulates peristalsis
Bladder - increased bladder tone
Ocular - constriction; decreased intraocular pressure - to treat glaucoma
Cholinergic - colon - slows everything down; rest and digest |
What is the parasympathetic nervous system's effects? | Digestion of food
Excretion of wastes
Also affects vision and reduces cardiac work |
What are the adrenergic receptors? | Beta-1 = cardiac
Beta-2 = lungs
Alpha = arteries
Adrenergic = ADD energy |
What are side effects of adrenergic agents? | Tachycardia
Hypertension
Palpitation - heart jumping out of chest (flight or fight)
Nervousness, insomnia, fine tremors |
What do sympathetic adrenergic agents do (target organs)? | Epinephrine is the prototype
Cardiac - increased HR
Respiratory - bronchial dilation
Eyes - dilate
Arteries - vasoconstriction |
What are the three main functions of the sympathetic nervous system? | Temperature control
Flight-or-fight response
Regulate the cardiovascular system |
What are the influences on the heart and blood vessels by the sympathetic nervous system? | HR increases; increased cardiac output
Blood vessels vasoconstrict
BP increases |
If you do not drink enough H2O or lost a lot of H2O, how would this affect these systems? | Renal perfusion - decrease
Renal blood pressure - decrease
Glomerular filtration rate - decrease
ADH secretion - increase
Urine output - decrease
Aldosterone level - increase
Blood pressure - decreased |
What are causes of third space fluid retention? | Water not being held in by albumin in cells; decreased colloid pressure
Fluid overload
Increased hydrostatic blood pressure forces fluid out of the cells |
Isotonic, hypotonic, hypertonic | Isotonic = 0.9% NS or 0.9% NaCl
Hypotonic = fewer electrolytes, more H2O; water into cells
Hypertonic = more electrolytes, less H2O; water out of cells
If you're dehydrated, want to give a hypotonic solution |
What are some properties of potassium ion? | ECF levels of 3.5 - 5 mEq/L
Major intracellular ion
Responsible for transmission of nerve impulses - cardiac and skeletal
90% of K+ gets excreted in urine |
What are some causes of hyperkalemia? | > 5 mEq/L
Excess intake
Decreased loss
Shifting K+ out of cells and H+ in; acidosis
Massive tissue damage - crushing and burns |
What are symptoms of hyperkalemia? | GI - hyperactive bowel sounds, nausea, vomiting, diarrhea
CNS - numbness, paresthesia
Muscles - irritability, hyperactive reflexes
Cardiovascular - Peak T waves, ventricular fibrilation, cardiac arrest
Kidneys - oliguria |
What are nursing interventions for hyperkalemia? | Monitor blood levels and signs/symptoms
Give Lasix - promotes K+ loss
Insulin and dextrose infusion will bring K+ from ECF into ICF and "hide" it
Dialysis - last resort to pull out K+
Ion exchange resin enema (replace K+ with Na+) |
What are some causes of hypokalemia? | < 3.5 mEq/L
Decreased intake
Increased loss (taking Lasix, vomiting, diarrhea, long-term steroid use)
Shift of K+ into cells and H+ out (metabolic alkalosis)
Oliguria |
What are side effects of hypokalemia? | Cardiovascular - Flattened T waves (U waves), EKG changes
Kidneys - renal damage, diminished capacity to concentrate urine
GI - anorexia, nausea, paralytic ileus = quiet bowel sounds
CNS - lethargy, confusion, diminished DTRs
Muscles - paralysis |
What are nursing interventions for hypokalemia? | Stop loss
Monitor blood level and signs/symptoms
Food replacement
Oral supplement - GI irritant, so take with food
IV therapy - irritating to vein, needs to be dilute; IV push would kill patient |
What are some causes of hypernatremia? | > 145 mEq/L
Decreased water intake (NPO)
Increased water output - diarrhea, diaphoresis, fever, diabetes insipidus
Increased Na+ intake - IV solution, near-drowning in sea water |
What are some side effects of hypernatremia? | > 145 mEq/L
Excessive thirst
Skin and mucous membranes - red, dry tongue, flush skin, nonelastic skin turgor, sticky membranes (mouth is dry)
CNS - restlessness, agitation
Renal - anuria, oliguria |
What are nursing interventions for hypernatremia? | > 145 mEq/L
Stop cause
Monitor blood level and signs/symptoms
Replace H2O to dilute Na+ - oral intake or IV hypotonic solution
Protect patient if confused
Decrease diet intake = salty food |
What are some caused of hyponatremia? | < 135 mEq/L
Loss of Na+ without H2O loss; excess H2O but low Na+
Increased H2O intake - Na+free IV fluids, tap water enema
Decreased H2O output - renal disease
Increased Na+ loss - vomiting, irrigating NG tube with water
Decreased Na+ intake |
What are effects of hyponatremia? | < 135 mEq/L
GI - absence of thirst, abdominal cramping
Skin and mucous membranes - clammy skin, finger printing on sternum
CNS - disorientation, headache
Muscle - fatigue |
What are nursing interventions for hyponatremia? | Stop the cause
Monitor blood levels, signs/symptoms
Decrease water intake
Fluid replacement with Na+ (oral and IV)
Irrigate NG tube with NaCl |