PRN Medications Flashcards
What are PRN Medications used for?
Prescription and administration of medications based on the immediate needs of patients, rather than prescheduled administration times determined by prescribing physician/pharmacist. They are used to relieve symptoms and not to treat an underlying disease
They are the responsibility of the nurse using clinical judgement
Acetaminophen (indications, action, absorption, distribution, metabolism and excretion, contraindication, cautious usage, adverse reactions)
Indication: treatment of mild pain, fever
Action: inhibits synthesis of prostaglandins that may serve as mediators of pain and fever, primarily in CNS. Has no significant anti-inflammatory properties or GI-toxicity
Absorption: well absorbed
Distribution: crosses the placenta; enters the breast milk in low concentrations
Metabolism and Excretion: 85% to 95% metabolized by the liver. Excreted by the kidney
Contraindicated in: previous hypersensitivity; severe hepatic impairment
Use cautiously in: hepatic/renal disease, alcoholism, chronic malnutrition
Adverse Reactions: hepatotoxicity, Stevens-Johnson Syndrome
Acetaminophen (Nursing implications, Patient/family teaching)
Nursing implications:
- Patients who are malnourish or chronically abuse alcohol are at higher risk of developing hepatotoxicity with chronic use of usual doses of acetaminophen
- For short-term use, combined doses of acetaminophen and salicylates should not exceed the recommended dose of either drug given alone
- Assess for rash periodically during therapy
- If overdose occurs, acetylcysteine is the antidote
Patient/Family teaching:
- Chronic excessive use of >4g/day (2g in chronic alcoholics) may lead to hepatotoxicity, renal, or cardiac damage
- Advise patient to avoid alcohol (3 or more glasses per day) if taking more than an occasional 1-2 doses.
- Advise patient to discontinue if rash occurs and notify HCP
Hydromorphone (indications, action, absorption, distribution, metabolism and excretion, contraindication, cautious usage, adverse reactions)
Indications: Moderate to severe pain (alone and in combination with non-opioid analgesics)
Action: Binds to opiate receptors in the CNS. Alters the perception of and response to painful stimuli, while producing generalized CNS depression
Absorption: Well absorbed
Distribution: crosses the placenta; enters the breast milk in low concentration
Metabolism and Excretion: Mostly by the liver
Contraindicated in: Previous hypersensitivity; severe respiratory depression; acute or severe bronchial asthma (opioids can cause release of pro-inflammatory mediators which cause asthma, and can also depress the respiratory drive)
Use Cautiously in: Head trauma (respiratory depression -> further decreases in O2 to the brain) and increased intracranial pressure (decreased respiratory rate -> increased CO2 in body -> increased vasodilation -> increased pressure in the brain), decreased liver function
Adverse Reactions: Confusion, sleepiness, delirium (decreased CNS activity), Hypotension (vasodilation through CO2 or histamine), bradycardia (through histamine), constipation (decrease gastric emptying and peristalsis)
Hydromorphone (Nursing implications, Patient/family teaching)
Nursing Implications:
- Assess BP, pulse, and RR before and periodically during administration
- If RR < 10/min, assess level of sedation
- Monitor for respiratory depression, especially during initiation or following increases in dose
- Assess bowel function routinely
- Naloxone (Narcan) is an opioid antagonist that can reverse respiratory depression or coma
Patient/Family Teaching:
- Advise patient that hydromorphone is a drug with known abuse potential. Protect it from theft, and never give to anyone other than the individual for whom it was prescribed
- Educate patients and caregivers on how to recognize respiratory depression and emphasize the importance of calling 9-1-1
Docusate (indications, action, absorption, distribution, metabolism and excretion, contraindication, cautious usage, adverse reactions)
Indications: Prevention of constipation for patients who should not be straining (ex. post myocardial infarction, or rectal surgery)
Action: Promotes incorporation of water into stool by modifying the consistency of the stool itself (reduces surface tension of stool, allowing water and fats to mix with stool), causing stool to be softer; stool softener
Absorption: Small amounts absorbed in the small intestine
Distribution: Unknown
Metabolism and Excretion: Eliminated in bile
Contraindicated in: Hypersensitivity; abdominal pain (bloating)
Use Cautiously in: Excessive or prolonged use may lead to dependence
Adverse Reactions: Throat irritation (bitter taste); mild cramps (bloating), diarrhea
Docusate (Nursing implications, Patient/family teaching)
Nursing Implications:
- Assess for abdominal distention, presence of bowel sounds, and usual pattern of bowel function
- Administer with a full glass of water or juice
- May be administered on an empty stomach for more rapid results
Patient/Family Teaching:
- Advise patients that laxatives should be used only for short-term therapy. Long-term therapy may cause electrolyte imbalance and dependence
- Encourage patients to use other forms of bowel regulation, such as increasing bulk in the diet, increasing fluid intake, and increasing mobility
- Advise patient not to use laxatives when abdominal pain, nausea, or vomiting
Senokot (indications, action, absorption, distribution, metabolism and excretion, contraindication, cautious usage, adverse reactions)
Indications: Treatment of constipation, particularly when associated with: slow transit time, constipating drugs, neurologic constipation (lack of urge to have a BM)
Action: Active components of sennosides alter water and electrolyte transport in the large intestine -> accumulation of water and increased peristalsis; stimulant laxative
Absorption: Small amounts absorbed in the small intestine
Distribution: Unknown
Metabolism and Excretion: Unknown
Contraindicated in: Hypersensitivity; abdominal pain (bloating)
Use Cautiously in: Excessive or prolonged use may lead to dependence
Adverse Reactions: Cramping, diarrhea
Senokot (Nursing implications, Patient/family teaching)
Nursing Implications:
- Assess patient for abdominal distention, presence of bowel sounds, and usual pattern of bowel function
- Assess colour, consistency, and amount of stool produced
Patient/Family Teaching:
- Advise patients that laxatives should be used only for short-term therapy. Long-term therapy may cause electrolyte imbalance and dependence
- Encourage patients to use other forms of bowel regulation, such as increasing bulk in the diet, increasing fluid intake, and increasing mobility
- Inform patient that this medication may cause a change in urine colour to pink, red, violet, yellow, or brown
Bisacodyl (indications, action, absorption, distribution, metabolism and excretion, contraindication, cautious usage, adverse reactions)
Indications: Treatment of constipation. Evacuation of the bowel before radiologic studies or surgeries. Part of a bowel regimen in spinal cord injury patients
Action: Stimulates peristalsis. Alters fluid and electrolyte transport, producing fluid accumulation in the colon; stimulant laxative
Absorption: Variable absorption
Distribution: Small amounts of metabolites excreted in breast milk
Metabolism and Excretion: Small amount by liver
Contraindicated in: Hypersensitivity; abdominal pain (bloating)
Use Cautiously in: Excessive or prolonged use may lead to dependence; use cautiously in patients with severe cardiovascular disease (can cause electrolyte imbalances - hypokalemia)
Adverse Reactions: Cramping, diarrhea
Bisacodyl (Nursing implications, Patient/family teaching)
Nursing Implications:
- Assess patient for abdominal distention, presence of bowel sounds, and usual patter of bowel function
- Assess colour, consistency, and amount of stool produced
Patient/Family Teaching:
- Prolonged therapy may cause electrolyte imbalance and dependence
- Advise patient to increase fluid intake to at least 1500 - 2000 mL/day during therapy to prevent dehydration
Polyethylene Glycol (indications, action, absorption, distribution, metabolism and excretion, contraindication, cautious usage, adverse reactions)
Indications: Treatment of occasional constipation
Action: Osmotic agent, drawing water into the lumen of the GI tract (mainly large intestine); osmotic laxative
Absorption: None
Distribution: Unknown
Metabolism and Excretion: Excreted in fecal content
Contraindicated in: Bowel obstruction
Use Cautiously in: Abdominal pain
Adverse Reactions: Cramping, bloating
Polyethylene (Nursing implications, Patient/family teaching)
Nursing Implications:
- Assess patient for abdominal distention, presence of bowel sounds, and usual patter of bowel function
- Assess colour, consistency, and amount of stool produced
Patient/Family Teaching:
- Inform patient that 2-4 days may be required to produce a bowel movement
Lorazepam (indications, action, absorption, distribution, metabolism and excretion, contraindication, cautious usage, adverse reactions)
Indications: Anxiety disorder; to decrease preoperative anxiety and induce amnesia
Action: Depresses the CNS by potentiating GABA (an inhibitory neurotransmitter)
Absorption: Well absorbed via oral administration
Distribution: Widely distributed. Crosses the blood brain barrier. Crosses the placenta. Enters breast milk
Metabolism and Excretion: Highly metabolized by the liver
Contraindicated in: Comatose patients; history of CNS depression
Use Cautiously in: Severe hepatic/renal/pulmonary impairment
Adverse Reactions: Bradycardia, hypotension, dizziness, drowsiness, lethargy, hangover
Lorazepam (Nursing implications, Patient/family teaching)
Nursing Implications:
- Assess risk for addiction, abuse, or misuse prior to administration
- Assess geriatric patients carefully for CNS reactions as they are more sensitive to these effects. Risk for falls
- Assess degree and manifestations of anxiety and mental status (orientation, mood, behaviour)
Patient/Family Teaching:
- Instruct patient to take medication exactly as directed and not to skip or double up on missed doses
- If medication is less effective after a few weeks, check with healthcare professional – do not increase dose
- Must discontinue gradually – do not suddenly stop
