Read Mosby's 2014 Nursing Drug Reference Online
Authors: Linda Skidmore-Roth
Mosby's 2014 Nursing Drug Reference (259 page)
Canada only Side effects:
italics
= common;
bold
= life-threatening 
Nurse Alert
HIGH ALERTmethadone (Rx)
(meth′a-done)
Dolophine, Metadol
, Methadose
Func. class.:
Opioid analgesic
Chem. class.:
Synthetic diphenylheptane derivative
Do not confuse:
methadone
/methylphenidate
Depresses pain impulse transmission at the spinal cord level by interacting with opioid receptors; produces CNS depression
Severe pain, opioid withdrawal
Hypersensitivity to this product or chlorobutanol (inj); asthma, ileus
Black Box Warning:
Respiratory depression
Precautions:
Pregnancy (C), breastfeeding, children <18 yr, geriatric patients, addictive personality, increased intracranial pressure, MI (acute), severe heart disease, respiratory depression, pulmonary/renal/hepatic disease, respiratory insufficiency, torsades de pointes, COPD
Black Box Warning:
QT prolongation, pain, substance abuse, potential for overdose, poisoning, accidental exposure
Calculator
• Adult:
PO/SUBCUT/IM/IV
2.5-10 mg q8-12hr prn
• Adult including pregnant woman:
20-30 mg initially unless low opioid tolerance expected; additional 5-10 mg q2-4hr as needed after initial dose; if symptoms continue, may give for ≤5 days
• Adult:
may need to be modified
Available forms:
Inj 10 mg/ml; tabs 5, 10 mg; oral sol 5, 10 mg/5 ml, 10 mg/ml
•
Rotating inj sites, give deep in large muscle mass (IM)
•
Pain and induration may occur at site
CNS:
Drowsiness, dizziness, confusion, headache, sedation
, euphoria,
seizures
CV:
Palpitations, bradycardia, change in B/P,
cardiac arrest, shock,
hypotension,
torsades de pointes, QT prolongation
EENT:
Tinnitus, blurred vision, miosis, diplopia
GI:
Nausea, vomiting, anorexia, constipation, cramps
, biliary tract spasm
GU:
Increased urinary output, dysuria, urinary retention, impotence
INTEG:
Rash
, urticaria, bruising, flushing, diaphoresis, pruritus
RESP:
Respiratory depression, respiratory arrest
Metabolized by liver; excreted by kidneys; crosses placenta; excreted in breast milk; half-life 8-59 hr, extended interval with continued dosing; 90% bound to plasma proteins
PO:
Onset 30-60 min, peak 1-1.5 hr, duration 6-8 hr, cumulative 22-48 hr; PO half as active as INJ
SUBCUT/IM:
Onset 10-20 min, peak 1½-2 hr, duration 4-6 hr, cumulative 22-48 hr
Unpredictable reactions: MAOIs; do not use together
•
Do not use within 2 wk of selegiline
Increase:
effects with other CNS depressants—alcohol, opiates, sedative/hyp
notics, antipsychotics, skeletal muscle relaxants
Increase:
toxicity—CYP3A4 inhibitors (aprepitant, antiretroviral protease inhibitors, clarithromycin, danazol, delavirdine, diltiazem, erythromycin, fluconazole, FLUoxetine, fluroxamine, imatinib, ketoconazole, mibefradil, nefazodone, telithromycin, voriconazole)
Increase:
QT prolongation—class IA antiarrhythmics (disopyramide, procainamide, quiNIDine), class III antiarrhythmics (amiodarone, dofetilide, ibutilide, sotalol), astemizole, arsenic trioxide, cisapride, chloroquine, clarithromycin, levomethadye, pentamidine, some phenothiazines, pimozide, terfenadine
Decrease:
analgesia—rifampin, phenytoin, nalbuphine, pentazine
Decrease:
methadone effect—CYP3A4 inducers (barbiturates, bosentan, carBAMazepine, efavirenz, phenytoins, nevira-pine, rifabutin, rifampin), withdrawal symptoms may occur
•
Avoid use with grapefruit juice
•
Avoid use with St. John’s wort; withdrawal may result
Increase:
CNS depression—chamomile, hops, kava, valerian
Increase:
amylase, lipase
•
Pain:
type, location, intensity, grimacing before, 1½-2 hr after administration; use pain scoring
•
I&O ratio; check for decreasing output; may indicate urinary retention
•
CNS changes: dizziness, drowsiness, hallucinations, euphoria, LOC, pupil reaction
•
Allergic reactions: rash, urticaria
Black Box Warning:
Respiratory dysfunction:
respiratory depression, character, rate, rhythm; notify prescriber if respirations are <10/min
Black Box Warning:
QT prolongation:
may be dose related or use with other products that increase QT
Black Box Warning:
Accidental exposure: make sure product is not accessible to children, pets
Black Box Warning:
Overdose, poisoning: advise persons involved in correct use
Black Box Warning:
Substance abuse: may occur but has less psychological dependence than other opiate agonists
•
Opioid detoxification: no analgesia occurs, only prevention of withdrawal symptoms
Black Box Warning:
B/P, pulse, ECG; hypotension, palpitations may occur
•
Bowel changes, bulk, fluids, laxatives should be used for constipation
•
Storage in light-resistant container at room temp
•
Assistance with ambulation
•
Therapeutic response: decrease in pain, successful opioid withdrawal
•
To report any symptoms of CNS changes, allergic reactions
•
That physical dependency may result from extended use
That withdrawal symptoms may occur: nausea, vomiting, cramps, fever, faintness, anorexia
•
To maintain proper hydration; to avoid alcohol use
Naloxone (Narcan) 0.2-0.8 mg IV, O
2
, IV fluids, vasopressors
Canada only Side effects:
italics
= common;
bold
= life-threatening Nurse Alert
