Mosby's 2014 Nursing Drug Reference (18 page)

acetaminophen (OTC)

(a-seat-a-mee′noe-fen)

Acephen, Apacet, APAP, Apra, Children’s Feverall, Equaline Children’s Pain Relief, Equaline Infant’s Pain Relief, Genapap, GoodSense Acetaminophen, GoodSense Children’s Pain Relief, Infantaire, Leader Children’s Pain Reliever, Mapap, Neopap, Ofirmev, Q-Pap, Q-Pap Children’s, Redutemp, Ridenol, Silapap, Tempra, T-Painol, Tylenol, Walgreen’s Non-Aspirin, XS pain reliever

Func. class.:
Nonopioid analgesic, antipyretic

Chem. class.:
Nonsalicylate, paraaminophenol derivative

ACTION:

May block pain impulses peripherally that occur in response to inhibition of prostaglandin synthesis; does not possess antiinflammatory properties; antipyretic action results from inhibition of prostaglandins in the CNS (hypothalamic heat-regulating center)

USES:

Mild to moderate pain or fever, arthralgia, dental pain, dysmenorrhea, headache, myalgia, osteoarthritis

Unlabeled uses:
Migraine

CONTRAINDICATIONS:

Hypersensitivity

Precautions:
Pregnancy (B), (C) IV; breastfeeding, geriatric patients, anemia, renal/hepatic disease, chronic alcoholism

DOSAGE AND ROUTES
Calculator

• Adult/child >12 yr: PO/RECT
325-650 mg q4-6hr prn, max 4 g/day; weight ≥50 kg IV 1000 mg q6hr or 650 mg q4hr prn, max single dose 1000 mg, min dosing interval 4 hr; weight <50 kg IV 15 mg/kg/dose q6hr or 12.5 mg/kg/dose q4hr, max single dose 15 mg/kg, min dosing interval 4 hr, max 75 mg/kg/day from all sources, ext rel 650-1300 mg q 8 hr as needed, max 4 g/day

• Child ≥2 yr and <50 kg: IV
15 mg/kg/dose q6hr or 12.5 mg/kg/dose q4hr, max single dose 15 mg/kg, min dosing interval 4 hr, max 75 mg/kg/day from all sources

• Child 1-12 yr: PO
10-15 mg/kg q4-6hr, max 5 doses/24 hr

• Child 1-12 yr: RECT
10-20 mg/kg/dose q4-6hr

• Neonate: RECT
10-15 mg/kg/dose q6-8hr

Migraine (unlabeled)

• Adult and adolescent: PO/RECT
500-1000 mg, max 1 g/dose or max 4 g/day

Available forms:
Rect supp 120, 325, 650 mg; soft chew tabs 80 mg; caps 500 mg; elix 120, 160, 325 mg/5 ml; oral disintegrating tab 80, 160 ml; oral drops 80 mg/0.8 ml, liquid 500 mg/5 ml, 160/5 ml, 1000/30 ml; ext rel 650 mg, 80 mg/ml; tabs 325, 500, 650 mg; sol for inj 1000 mg/100 ml

Administer:
PO route

• 
Crushed or whole, do not crush EXT REL product; chewable tabs may be chewed; give with full glass of water

• 
With food or milk to decrease gastric symptoms if needed

• 
Susp after shaken well; check elixir, liquid, suspension concentration carefully, susp and cups are bioequivalent

Intermittent IV INF route

• 
No further dilution needed; do not add other medications to vial or inf device

• 
For doses equal to single vial, averted IV set may be used to deliver directly from vial; for doses less than a single vial, withdraw dose and place in an empty sterile syringe, plastic IV container, or glass bottle; infuse over 15 min

• 
Discard unused portion; if seal is broken, vial penetrated, or drug transferred to another container, give within 6 hr

SIDE EFFECTS

GI:
Nausea, vomiting, abdominal pain;
hepatotoxicity, hepatic seizure (overdose), GI bleeding

GU:
Renal failure (high, prolonged doses)

HEMA:
Leukopenia, neutropenia, hemolytic anemia (long-term use), thrombocytopenia, pancytopenia

INTEG:
Rash, urticaria

SYST:
Hypersensitivity

TOXICITY:
Cyanosis, anemia, neutropenia, jaundice, pancytopenia, CNS stimulation, delirium followed by vascular collapse, seizures, coma, death

PHARMACOKINETICS

85%-90% metabolized by liver, excreted by kidneys; metabolites may be toxic if overdose occurs; widely distributed; crosses placenta in low concentrations; excreted in breast milk; half-life 1-4 hr

PO:
Onset 10-30 min, peak 1/2-2 hr, duration 4-6 hr, well absorbed

RECT:
Onset slow, peak 1-2 hr, duration 4-6 hr, absorption varies

INTERACTIONS

• 
Avoid use with salicylates

• 
Renal adverse reactions: NSAIDs, salicylates

Increase:
Hypoprothrombinemia: warfarin, long-term use, high doses of acetaminophen

Increase:
hepatotoxicity—barbiturates, alcohol, carbamazepine, hydantoins, rifampin, rifabutin, isoniazid, diflunisal, zidovudine, lamotrigine, imatinib

Decrease:
absorption—colestipol, cholestyramine

Drug/Herb

Increase:
heptatotoxicity—St. John’s wort, due to acetaminophen metabolism

Increase:
hepatotoxicity—echinacea (rare)

Drug/Lab Test

Interference:
5-HIAA

Increase:
LFTs, potassium, bilirubin, LDH, pro-time

Decrease:
Hgb/Hct, WBC, RBC, platelets; albumin, magnesium, phosphate (pediatrics)

NURSING CONSIDERATIONS
Assess:

• 
Hepatic studies: AST, ALT, bilirubin, creatinine before therapy if long-term therapy is anticipated; may cause hepatic toxicity at doses >4 g/day with chronic use

• 
Renal studies: BUN, urine creatinine, occult blood, albumin, if patient is on long-term therapy; presence of blood or albumin indicates nephritis

• 
Blood studies: CBC, PT if patient is on long-term therapy

• 
I&O ratio; decreasing output may indicate renal failure (long-term therapy)

• 
For fever and pain: type of pain, location, intensity, duration

• 
Chronic poisoning:
rapid, weak pulse; dyspnea; cold, clammy extremities; report immediately to prescriber

• 
Hepatotoxicity:
dark urine; clay-colored stools; yellowing of skin, sclera; itching; abdominal pain; fever; diarrhea if patient is on long-term therapy

• 
Allergic reactions:
rash, urticaria; if these occur, product may have to be discontinued

Perform/provide:

• 
Storage of suppositories <80° F (27° C)

Evaluate:

• 
Therapeutic response: absence of pain using pain scoring; fever

Teach patient/family:

 
Not to exceed recommended dosage; the elixir, liquid, suspension come in several concentrations, read label carefully; acute poisoning with liver damage may result; tell parents of children to check products carefully; that acute toxicity includes symptoms of nausea, vomiting, abdominal pain and that prescriber should be notified immediately; that toxicity may occur when used with other combination products

• 
Not to use with alcohol, herbals, OTC products without approval of prescriber

• 
May be used when breastfeeding, short-term

• 
To recognize signs of chronic overdose: bleeding, bruising, malaise, fever, sore throat

• 
That those with diabetes may notice blood glucose monitoring changes

• 
To notify prescriber of pain or fever lasting more than 3 days, not to be used in patients <2 yr unless approved by prescriber

TREATMENT OF OVERDOSE:

Product level, gastric lavage, activated charcoal; administer oral acetylcysteine to prevent hepatic damage
(
see acetylcysteine monograph
);
monitor for bleeding

Canada only   Side effects:
italics
= common;
bold
= life-threatening   
Nurse Alert

acetaZOLAMIDE (Rx)

(a-set-a-zole′a-mide)

Diamox Sequels

Func. class.:
Diuretic, carbonic anhydrase inhibitor, antiglaucoma agent, antiepileptic

Chem. class.:
Sulfonamide derivative

Do not confuse:
acetaZOLAMIDE
/
acetoHEXAMIDE

Diamox
/
Trimox/Dobutrex

ACTION:

Inhibits carbonic anhydrase activity in proximal renal tubules to decrease reabsorption of water, sodium, potassium, bicarbonate resulting in increased urine volume and alkalinization of urine; decreases carbonic anhydrase in CNS, increasing seizure threshold; able to decrease secretion of aqueous humor in eye, which lowers intraocular pressure

USES:

Open-angle glaucoma, angle-closure glaucoma (preoperatively, if sur
gery delayed), seizures (petit mal, grand mal, mixed, absence), edema in CHF, product-induced edema, acute altitude sickness

Unlabeled uses:
Urine alkalinization, metabolic alkalosis in mechanical ventilation, decrease CSF production in infants with hydrocephalus, familial periodic paralysis, nystagmus

CONTRAINDICATIONS:

Hypersensitivity to sulfonamides, severe renal/hepatic disease, electrolyte imbalances (hyponatremia, hypokalemia), hyperchloremic acidosis, Addison’s disease, long-term use for closed-angle glaucoma, adrenocortical insufficiency

Precautions:
Pregnancy (C), breastfeeding, hypercalciuria, respiratory acidosis, pulmonary obstruction/emphysema, COPD

DOSAGE AND ROUTES
Calculator
Angle-closure glaucoma

• Adult: PO/IV
250 mg q4hr or 250 mg bid for short-term therapy

Open-angle glaucoma

• Adult: PO/IV
250 mg/day in divided doses for amounts of more than 250 mg or 500 mg
EXT REL
bid, max 1 g/day

Edema in CHF

• Adult: PO/IV
250-375 mg/day or 5 mg/kg in
AM,
give for 2 days, then 1-2 days drug free

• Child: PO/IV
5 mg/kg/day or 150 mg/m
2
in
AM

Seizures

• Adult: PO/IV
8-30 mg/kg/day, in 1-4 divided doses, usual range 375-1000 mg/day;
ER
not recommended with seizures

• Child: PO/IV
8-30 mg/kg/day in divided doses tid or qid, or 300-900 mg/m
2
/day, not to exceed 1 g/day

Altitude sickness

• Adult: PO
250 mg q6-12hr;
EXT REL
500 mg q12-24hr, start therapy 24-48 hr before ascent and give for ≥48 hr after arrival at high altitude

• Geriatric:
PO
250 mg bid, use lowest effective dose

Renal dose

• Adult: PO/IV
CCr 50-80 ml/min give dose ≥6 hr reg rel of IV; CCr 10-50 ml/min give dose q12hr; CCr <10 ml/min, avoid use

Infants with hydrocephalus (unlabeled)

• Infant: PO/IV
5 mg/kg q6hr, may increase by 25 mg/kg/day; max 100 mg/kg/day

Urine alkalinization (unlabeled)

•Adult: IV
5 mg/kg/dose, repeat 2-3× over 24 hr

Familial periodic paralysis (unlabeled)

• Adult: PO
250-375 mg/day in divided doses

Metabolic alkalosis in mechanical ventilation (unlabeled)

•Adult: IV
500 mg as a single dose or 250 mg q6hr × 4 doses

Vestibular nystagmus (unlabeled)

• Adult: PO
250 mg, increase by 250 mg q3days; max 3 g/day in divided doses

Available forms:
Tabs 125, 250 mg; ext rel caps 500 mg; inj 500 mg

Administer:

• 
In
AM
to avoid interference with sleep if using product as diuretic

• 
Potassium replacement if potassium level is <3 mg/dl

PO route

• 
Do not break, crush, or chew ext rel caps; this product should be used for altitude sickness, glaucoma

• 
With food if nausea occurs; absorption may be decreased slightly

IV route

• 
After diluting 500 mg in ≥5 ml sterile water for inj;
direct IV:
give at 100-500 mg/min;
intermittent INF:
may be diluted further in LR, D
5
W, D
10
W, 0.45% NaCl, 0.9% NaCl, or Ringer’s sol and infused over 15-30 min; use within 24 hr of dilution

Additive compatibilities:
cimetidine, ranitidine

SIDE EFFECTS

CNS:
Anxiety,
confusion
,
seizures,
depression
, dizziness,
drowsiness, fatigue
, headache,
paresthesia
, stimulation

EENT:
Myopia, tinnitus

ENDO:
Hyperglycemia

GI:
Nausea, vomiting, anorexia, diarrhea
, melena,
weight loss
,
hepatic insufficiency, cholestatic jaundice, fulminant hepatic necrosis,
taste alterations
,
bleeding

GU:
Frequency, polyuria
,
uremia,
glucosuria, hematuria, dysuria, crystalluria, renal calculi

HEMA:
Aplastic anemia, hemolytic anemia, leukopenia, thrombocytopenia, purpura, pancytopenia

INTEG:
Rash
, pruritus, urticaria, fever,
Stevens-Johnson syndrome,
photosensitivity, flushing,
toxic epidermal necrolysis

META:
Hypokalemia, hyperchloremic acidosis
, hyponatremia, sulfonamide-like reactions, metabolic acidosis

PHARMACOKINETICS

65% absorbed if fasting (oral), 75% absorbed if given with food; half-life 2½-5½ hr; excreted unchanged by kidneys (80% within 24 hr), crosses placenta

PO:
Onset 1-1½ hr, peak 2-4 hr, duration 8-12 hr

PO-EXT REL:
Onset 2 hr, peak 8-12 hr, duration 18-24 hr

IV:
Onset 2 min, peak 15 min, duration 4-5 hr

INTERACTIONS

Increase:
action of—amphetamines, flecainide, memantine, phenytoin, procainamide, quinidine, anticholinergics, methenamine, mecamylamine, ePHEDrine, memantine, mexiletene, quiNIDine, folic acid antagonists

Increase:
excretion of lithium, primidone

Increase:
osteomalacia—carBAMazepine, ethotoin

Increase:
toxicity—salicylates, cycloSPORINE

Increase:
hypokalemia—corticosteroids, amphotericin B, corticotropin, ACTH

Increase:
cardiac toxicity if hypokalemia develops—arsenic trioxide, cardiac glycosides, levomethadyl

Increase:
renal stone formation, heat stroke—topiramate (avoid concurrent use)

Decrease:
primidone levels

Drug/Lab Test

Increase:
glucose, bilirubin, calcium, uric acid

Decrease:
thyroid iodine uptake

False positive:
urinary protein, 17 hydroxysteroid

NURSING CONSIDERATIONS
Assess:

• 
Edema: weight daily, I&O daily to determine fluid loss; effect of product may be decreased if used daily; monitor geriatric patients for dehydration

• 
Ocular status: intraocular pressure, ophthalmologic examination

• 
For cross-sensitivity with other sulfonamides and this product

• 
B/P lying, standing; postural hypotension may occur

• 
Electrolytes: potassium, sodium, chloride; also BUN, blood glucose, CBC, serum creatinine, blood pH, ABGs, LFTs; I&O, platelet count, patient may need to be on a high-potassium diet; identify signs of hypokalemia (vomiting, fatigue, weakness)

• 
Seizures:
neurologic status, provide seizure precaution

Perform/provide:

• 
Storage in dark, cool area; use reconstituted solution within 24 hr

Evaluate:

• 
Therapeutic response: improvement in edema of feet, legs, sacral area daily if medication is being used for CHF; decrease in aqueous humor if medication is being used for glaucoma; decreased frequency of seizures, prevention of altitude sickness

Teach patient/family:

• 
To take exactly as prescribed; if dose is missed, take as soon as remembered; do not double dose

• 
Altitude sickness: to avoid rapid ascent

• 
Diabetic: that drug may increase blood glucose and to monitor blood glucose

• 
To use sunscreen to prevent photosensitivity

• 
To avoid hazardous activities if drowsiness occurs

• 
To increase fluids to 2-3 L/day if not contraindicated

 
To report nausea, vertigo, rapid weight gain, change in stools, weakness, numbness, rash, sore throat, bleeding/bruising; Stevens-Johnson syndrome, toxic epidermal necrolysis (blistering, red rash that spreads)

TREATMENT OF OVERDOSE:

Lavage if taken orally; monitor electrolytes; administer dextrose in saline; monitor hydration, CV, renal status

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