Meperidine

Name: Meperidine

  • Chronic Pain
  • Pain Management
  • Pain Management Medication Types
  • Pain Management: Musculoskeletal Pain

What is meperidine?

Meperidine is an opioid pain medication. An opioid is sometimes called a narcotic.

Meperidine is used to treat moderate-to-severe pain.

Meperidine may also be used for purposes not listed in this medication guide.

What happens if I miss a dose?

Since meperidine is used for pain, you are not likely to miss a dose. Skip any missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

Meperidine side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Like other opioid medicines, meperidine can slow your breathing. Death may occur if breathing becomes too weak. A person caring for you should seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.

Stop using meperidine and call your doctor at once if you have:

  • weak or shallow breathing, slow heartbeat;

  • severe drowsiness, feeling like you might pass out;

  • confusion, mood changes, agitation, hallucinations;

  • tremors, muscle movements you cannot control, or a seizure (convulsions);

  • infertility, missed menstrual periods;

  • impotence, sexual problems, loss of interest in sex; or

  • low cortisol levels--nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Meperidine is more likely to cause breathing problems in older adults and people who are severely ill, malnourished, or otherwise debilitated.

Long-term use of opioid medication may affect fertility (ability to have children) in men or women. It is not known whether opioid effects on fertility are permanent.

Common side effects may include:

  • dizziness, drowsiness;

  • headache;

  • nausea, vomiting; or

  • sweating.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Uses For meperidine

Meperidine is used to relieve moderate to severe pain. It belongs to the group of medicines called narcotic analgesics (pain medicines). Meperidine acts on the central nervous system (CNS) to relieve pain. meperidine should not be used to relieve chronic (long-lasting or recurrent) pain.

When meperidine is used for a long time, it may become habit-forming, causing mental or physical dependence. However, people who have continuing pain should not let the fear of dependence keep them from using narcotics to relieve their pain. Mental dependence (addiction) is not likely to occur when narcotics are used for this purpose. Physical dependence may lead to withdrawal side effects if treatment is stopped suddenly. However, severe withdrawal side effects can usually be prevented by gradually reducing the dose over a period of time before treatment is stopped completely.

meperidine is available only with your doctor's prescription.

Precautions While Using meperidine

It is very important that your doctor check your progress while you are taking meperidine. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to use it.

Do not use meperidine if you are using or have used a monoamine oxidase (MAO) inhibitor in the past 2 weeks. MAO inhibitors are used for depression, and some examples are isocarboxazid (Marplan®), phenelzine (Nardil®), selegiline (Eldepryl®), and tranylcypromine (Parnate®). If meperidine is used with MAO inhibitors, you may have unwanted effects like confusion, agitation, restlessness, stomach or intestinal symptoms, a sudden high temperature, an extremely high blood pressure, or convulsions.

Symptoms of an overdose include: extreme dizziness or weakness, trouble breathing, slow heartbeat or breathing, seizures, and cold, clammy skin. In case of an overdose, call your doctor right away.

meperidine will add to the effects of alcohol and other CNS depressants (medicines that can make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicine, other prescription pain medicine or narcotics, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the medicines listed above while you are using meperidine.

meperidine may be habit-forming. If you feel that the medicine is not working as well, do not use more than your prescribed dose. Call your doctor for instructions.

Using narcotics for a long time can cause severe constipation. To prevent this, your doctor may direct you to take laxatives, drink a lot of fluids, or increase the amount of fiber in your diet. Be sure to follow the directions carefully, because continuing constipation can lead to more serious problems.

Dizziness, lightheadedness, or fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help lessen this problem. Also, lying down for a while may relieve the dizziness or lightheadedness.

meperidine may make you dizzy, drowsy, confused, or disoriented. Make sure you know how you react to meperidine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are using meperidine. Serious unwanted effects can occur if certain medicines are given together with meperidine.

If you have been using meperidine regularly for several weeks or longer, do not change your dose or suddenly stop using it without checking with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely. This may help reduce the possibility of withdrawal symptoms, such as abdominal or stomach cramps, anxiety, fever, nausea, runny nose, sweating, tremors, or trouble sleeping.

Using meperidine while you are pregnant may cause serious unwanted effects in your newborn baby. Tell your doctor right away if you think you are pregnant or if you plan to become pregnant while using meperidine.

Using too much of meperidine may cause infertility (unable to have children). Talk with your doctor before using meperidine if you plan to have children.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.

Meperidine - Clinical Pharmacology

Mechanism of Action

Meperidine is an opioid agonist with multiple actions qualitatively similar to those of morphine; the most prominent of these involve the central nervous system and organs composed of smooth muscle. The principal actions of therapeutic value are analgesia and sedation.

Pharmacodynamics

Effects on the Central Nervous System

Meperidine produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and electrical stimulation.

Meperidine causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origins may produce similar findings). Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations.

Effects on the Gastrointestinal Tract and Other Smooth Muscle

Meperidine causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach and duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm, resulting in constipation. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions, spasm of sphincter of Oddi, and transient elevations in serum amylase.

Effects on the Cardiovascular System

Meperidine produces peripheral vasodilation, which may result in orthostatic hypotension or syncope. Manifestations of histamine release and/or peripheral vasodilation may include pruritus, flushing, red eyes, sweating, and/or orthostatic hypotension.

Effects on the Endocrine System

Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and luteinizing hormone (LH) in humans [see Adverse Reactions (6)]. They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon.

Chronic use of opioids may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date [see Adverse Reactions (6)].

Effects on the Immune System

Opioids have been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive.

Concentration–Efficacy Relationships

The minimum effective analgesic concentration will vary widely among patients, especially among patients who have been previously treated with potent agonist opioids. The minimum effective analgesic concentration of Meperidine for any individual patient may increase over time due to an increase in pain, the development of a new pain syndrome, and/or the development of analgesic tolerance [see Dosage and Administration (2.1)].

Concentration–Adverse Reaction Relationships

There is a relationship between increasing Meperidine plasma concentration and increasing frequency of dose-related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid-tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions [see Dosage and Administration (2.1)].

Pharmacokinetics

Absorption

Oral bioavailability of Meperidine is approximately 50%.

Elimination

The elimination half-life is 3 to 8 hours in healthy volunteers. The only bioactive metabolite is norMeperidine which has an average elimination half-life of 20.6 hours.

Metabolism

Meperidine is metabolized through biotransformation. In vitro data show Meperidine is metabolized to norMeperidine in liver mainly by CYP3A4 and CYP2B6.

Excretion

Meperidine and norMeperidine are excreted by kidneys.

Age

In clinical studies reported in the literature, changes in several pharmacokinetic parameters with increasing age have been observed. The initial volume of distribution and steady-state volume of distribution may be higher in elderly patients than in younger patients. The free fraction of Meperidine in plasma may be higher in patients over 45 years of age than in younger patients.

Hepatic impairment

The elimination half-life is 3 to 8 hours in healthy volunteers and is 1.3 to 2 times greater in postoperative or cirrhotic patients.

Drug Interactions Studies

Phenytoin

The hepatic metabolism of Meperidine may be enhanced by phenytoin. Concomitant administration resulted in reduced half-life and bioavailability with increased clearance of Meperidine in healthy subjects; however, blood concentrations of norMeperidine were increased [see Drug Interactions (7)].

Ritonavir

Plasma concentrations of the active metabolite norMeperidine may be increased by ritonavir [see Drug Interactions (7)].

Acyclovir

Plasma concentrations of Meperidine and its metabolite, norMeperidine, may be increased by acyclovir [see Drug Interactions (7)].

Cimetidine

Cimetidine reduced the clearance and volume of distribution of Meperidine and also the formation of the metabolite, norMeperidine, in healthy subjects [see Drug Interactions (7)].

Pronunciation

(me PER i deen)

Special Populations Hepatic Function Impairment

Accumulation of meperidine and/or normeperidine may occur. Half-life is 1.3 to 2 times greater in cirrhotic patients.

Dosing Adult

Note: The American Pain Society (2008) and ISMP (2007) do not recommend meperidine’s use as an analgesic. If use in acute pain (in patients without renal or CNS disease) cannot be avoided, treatment should be limited to ≤48 hours and doses should not exceed 600 mg/24 hours. Oral route is not recommended for treatment of acute or chronic pain. If IV route is required, consider a reduced dose. Patients with prior opioid exposure may require higher initial doses.

Pain management:

Acute pain: Oral, IM, SubQ: 50 to 150 mg every 3 to 4 hours as needed.

Discontinuation of therapy: For patients on long term opioid therapy, decrease dose by 25% to 50% every 2 to 4 days; monitor for signs/symptoms of withdrawal. If patient displays withdrawal symptoms, increase dose to previous dose and then reduce dose more slowly by increasing interval between dose reductions, decreasing amount of daily dose reduction, or both.

Obstetrical analgesia: IM, SubQ: 50 to 100 mg when pain becomes regular; may repeat at 1- to 3-hour intervals.

Preoperatively: IM, SubQ: 50 to 100 mg administered 30 to 90 minutes before the beginning of anesthesia.

Dosage adjustment for concomitant therapy: Concomitant phenothiazines/tranquilizers: Reduce meperidine dose by 25% to 50% when administered concomitantly with phenothiazines and other tranquilizers.

Postoperative shivering (off-label use): IV: 25 to 50 mg once (Crowley 2008; Kranke 2002; Mercandante 1994; Wang 1999)

ALERT U.S. Boxed Warning

Addiction, abuse, and misuse

Meperidine exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death. Assess each patient’s risk prior to prescribing meperidine, and monitor all patients regularly for the development of these behaviors and conditions.

Life-threatening respiratory depression

Serious, life-threatening, or fatal respiratory depression may occur with use of meperidine. Monitor for respiratory depression, especially during initiation of meperidine or following a dose increase.

Accidental ingestion

Accidental ingestion of meperidine, especially by children, can result in a fatal overdose of meperidine.

Neonatal opioid withdrawal syndrome

Prolonged use of meperidine during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening if not recognized and treated, and requires management according to protocols developed by neonatology experts. If opioid use is required for a prolonged period in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available.

Cytochrome P450 3A4 interaction

The concomitant use of meperidine with all cytochrome P450 3A4 inhibitors may result in an increase in meperidine plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression. In addition, discontinuation of a concomitantly used cytochrome P450 3A4 inducer may result in an increase in meperidine plasma concentration. Monitor patients receiving meperidine and any CYP3A4 inhibitor or inducer.

Risks from concomitant use with benzodiazepines or other CNS depressants

Concomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of meperidine and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate. Limit dosage and duration to the minimum required. Follow patients for signs and symptoms of respiratory depression and sedation.

Concomitant use of meperidine with MAOIs

Concomitant use of meperidine with MAOIs can result in coma, severe respiratory depression, cyanosis, and hypotension. Use of meperidine with MAOIs within last 14 days is contraindicated.

Warnings/Precautions

Concerns related to adverse effects:

• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).

• CNS events: Normeperidine (an active metabolite and CNS stimulant) may accumulate and precipitate anxiety, tremors, or seizures; risk increases with preexisting CNS or renal dysfunction, prolonged use (>48 hours), and cumulative dose (>600 mg/24 hours in adults). Oral meperidine should not be used since first-pass metabolism decreases efficacy while increasing normeperidine concentrations (American Pain Society 2008). Note: Naloxone does not reverse, and may even worsen, neurotoxicity.

• Constipation: May cause constipation which may be problematic in patients with unstable angina and patients post-myocardial infarction. Consider preventive measures (eg, stool softener, increased fiber) to reduce the potential for constipation.

• Hypotension: May cause severe hypotension (including orthostatic hypotension and syncope); use with caution in patients with hypovolemia, cardiovascular disease (including acute MI), or drugs which may exaggerate hypotensive effects (including phenothiazines or general anesthetics). Monitor for symptoms of hypotension following initiation or dose titration. Use caution. Avoid use in patients with circulatory shock.

• Respiratory depression: [US Boxed Warning]: Serious, life-threatening, or fatal respiratory depression may occur. Monitor closely for respiratory depression, especially during initiation or dose escalation. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.

• Serotonin syndrome: May occur with concomitant use of serotonergic agents (eg, SSRIs, SNRIs, triptans, TCAs), lithium, St. John’s wort, agents that impair metabolism of serotonin (eg, MAO inhibitors), or agents that impair metabolism of tramadol (eg, CYP2D6 and 3A4 inhibitors). Monitor patients for serotonin syndrome such as mental status changes (eg, agitation, hallucinations, coma); autonomic instability (eg, tachycardia, labile blood pressure, hyperthermia); neuromuscular changes (eg, hyperreflexia, incoordination); and/or GI symptoms (eg, nausea, vomiting, diarrhea).

Disease-related concerns:

• Abdominal conditions: May obscure diagnosis or clinical course of patients with acute abdominal conditions.

• Adrenocortical insufficiency: Use with caution and reduce initial dosage in patients with adrenal insufficiency, including Addison disease. Long-term opioid use may cause secondary hypogonadism, which may lead to sexual dysfunction, infertility, mood disorders, and osteoporosis (Brennan 2013).

• Biliary tract impairment: Use with caution in patients with biliary tract dysfunction, including acute pancreatitis; opioids may cause constriction of sphincter of Oddi.

• CNS depression/coma: Avoid use in patients with impaired consciousness or coma as these patients are susceptible to intracranial effects of carbon dioxide retention.

• Delirium tremens: Use with caution in patients with delirium tremens.

• Head trauma: Use with extreme caution in patients with head injury, intracranial lesions, or elevated intracranial pressure (ICP); exaggerated elevation of ICP may occur.

• Hepatic impairment: Use with caution in patients with hepatic disorders; meperidine and to a lesser degree normeperidine may accumulate and precipitate either CNS depression or CNS excitation (eg, anxiety, tremors, or seizures) (Danzinger 1994; Tegeder 1999).

• Obesity: Use with caution in patients who are morbidly obese.

• Pheochromocytoma: Use with caution in patients with pheochromocytoma.

• Prostatic hyperplasia/urinary stricture: Use with caution and reduce initial dosage in patients with prostatic hyperplasia and/or urinary stricture.

• Psychosis: Use with caution in patients with toxic psychosis.

• Renal impairment: Avoid use in patients with renal impairment (American Pain Society 2008; ISMP 2007); normeperidine may accumulate and precipitate anxiety, tremors, or seizures.

• Respiratory disease: Use with caution and monitor for respiratory depression in patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or preexisting respiratory depression, particularly when initiating and titrating therapy; critical respiratory depression may occur, even at therapeutic dosages. Consider the use of alternative nonopioid analgesics in these patients.

• Seizure disorders: Use with caution in patients with seizure disorders, may cause or aggravate seizures if high doses used or from prolonged use (accumulation of metabolite).

• Sickle-cell disease: In patients with sickle cell anemia, use with caution and decrease initial dose; normeperidine (active metabolite) may accumulate and induce seizures in these patients; Note: Meperidine is not recommended for use in sickle cell patients by the American Pain Society (APS 2008) and should only be used in sickle cell patients with a vaso-occlusive crisis (VOC) if it is the only effective opioid for an individual patient (NHLBI 2014).

• Tachycardia: Use with caution in patients with atrial flutter and other supraventricular tachycardias; use may increase ventricular response rate possibly due to a vagolytic effect.

• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction, including hypothyroidism.

Concurrent drug therapy issues:

• Benzodiazepines or other CNS depressants: [US Boxed Warning]: Concomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of meperidine and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate. Limit dosage and durations to the minimum required and follow patients for signs and symptoms of respiratory depression and sedation.

• CYP3A4 interactions: [US Boxed Warning]: Use with all CYP3A4 inhibitors may result in an increase in meperidine plasma concentrations, which could increase or prolong adverse drug effects and may cause potentially fatal respiratory depression. In addition, discontinuation of a concomitant CYP3A4 inducer may result in increased meperidine concentrations. Monitor patients receiving meperidine and any CYP3A4 inhibitor or inducer.

• MAOI interactions: [US Boxed Warning]: Concomitant use of meperidine with MAOIs can result in coma, severe respiratory depression, cyanosis, and hypotension. Use of meperidine with MAOIs within last 14 days is contraindicated.

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• Cachectic or debilitated patients: Use with caution in cachectic or debilitated patients; there is a greater potential for critical respiratory depression, even at therapeutic dosages; reduce initial dosage. Consider the use of alternative nonopioid analgesics in these patients.

• Elderly: Avoid the use of meperidine for pain control, especially in elderly and renally compromised patients because of the risk of neurotoxicity (American Pain Society 2008; Institute for Safe Medication Practices [ISMP] 2007).

• Neonates: Neonatal withdrawal syndrome: [US Boxed Warning]: Prolonged use of opioids during pregnancy can cause neonatal withdrawal syndrome, which may be life-threatening if not recognized and treated according to protocols developed by neonatology experts. If opioid use is required for a prolonged period in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available. Signs and symptoms include irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. Onset, duration, and severity depend on the drug used, duration of use, maternal dose, and rate of drug elimination by the newborn.

Dosage form specific issues:

• Benzyl alcohol and derivatives: Some dosage forms may contain sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors 2001); avoid or use dosage forms containing benzyl alcohol derivative with caution in neonates. See manufacturer’s labeling.

• Parenteral: Administer IV injections very slowly, preferably in the form of a diluted solution. Do not administer IV unless a opioid antagonist and the facilities for assisted or controlled respiration are immediately available. When meperidine is given parenterally, especially IV, the patient should be lying down.

• Sulfites: Some preparations may contain sulfites which may cause allergic reaction.

Other warnings/precautions:

• Abuse/misuse/diversion: [US Boxed Warning]: Meperidine exposes patients and other users to the risks of addiction, abuse, and misuse, potentially leading to overdose and death. Assess each patient’s risk prior to prescribing; monitor all patients regularly for development of these behaviors or conditions. Use with caution in patients with a history of drug abuse or acute alcoholism; potential for drug dependency exists. Other factors associated with increased risk for misuse include younger age, concomitant depression (major), and psychotropic medication use.

• Accidental ingestion: [US Boxed Warning]: Accidental ingestion of even one dose, especially in children, can result in a fatal overdose of meperidine.

• Acute and/or cancer pain management: Meperidine offers no advantage over other opioids as an analgesic and has unique neurotoxicity. The use of meperidine in this setting should be avoided (American Pain Society [APS] 2008; ISMP 2007).

• Chronic pain management: Use is not recommended for the management of chronic pain.

• Optimal regimen: An opioid-containing analgesic regimen should be tailored to each patient's needs and based upon the the route of administration, degree of tolerance for opioids (naive versus chronic user), age, weight, and medical condition. The optimal analgesic dose varies widely among patients; doses should be titrated to pain relief/prevention.

• Surgery: Opioids decrease bowel motility; monitor for decreased bowel motility in postop patients receiving opioids. Use with caution in the perioperative setting; individualize treatment when transitioning from parenteral to oral analgesics.

• Withdrawal: Concurrent use of mixed agonist/antagonist analgesics (eg, pentazocine, nalbuphine, butorphanol) or partial agonist (eg, buprenorphine) analgesics may precipitate withdrawal symptoms and/or reduced analgesic efficacy in patients following prolonged therapy with mu opioid agonists. Taper dose gradually when discontinuing.

Usual Adult Dose for Pain

Oral:
50 to 150 mg orally every 3 to 4 hours as needed
Maximum dose: 600 mg per day

Parenteral:
50 to 150 mg IM or subcutaneously every 3 to 4 hours as needed; IM administration is preferred when repeated dose are required
-May be administered IV, however, lower doses are advised and administration should be very slow, preferably using a diluted solution

Patient Controlled Analgesia (PCA):
-Initial dose: 10 mg with a range of 1 to 5 mg per incremental dose; Lockout interval: 6 to 10 minutes; adjust dose based on patient response
For continuous IV infusion, the usual adult dose is 15 to 35 mg per hour

Comments:
-Due to the risks of addiction, abuse, and misuse, this drug should be reserved for use in patients for whom alternative treatment options have not been tolerated or are not expected to be tolerated or have not provided adequate analgesia, or are not expected to provide adequate analgesia.
-If adequate pain management cannot be achieved with a daily oral dose of 600 mg, alternative treatment is recommended.
-IV use should be restricted to settings in which a narcotic antagonist and facilities for assisted or controlled respiration are immediately available.
-The American Pain Society does not recommend use of this drug as an analgesic due to the accumulation of its toxic metabolite; this drug should not be used for the treatment of chronic pain.

Use: For the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate.

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