Pethidine, also known as meperidine and sold under the brand name Demerol among others, is a synthetic opioid pain medication. It was patented in 1937 and approved for medical use in 1943. For much of the 20th century, pethidine was the opioid of choice for many physicians; in 1975, 60% of doctors prescribed it for acute pain and 22% for chronic severe pain. Compared with morphine, pethidine was thought to be safer, carry a lower risk of addiction, and to be superior in treating the pain associated with biliary spasm or renal colic due to its putative anticholinergic effects. These were later discovered to be all myths, as it carries an equal risk of addiction, possesses no advantageous effects on biliary spasm or renal colic compared to other opioids, and due to its toxic metabolite norpethidine is more toxic than other opioids - especially during long-term use. The norpethidine metabolite was found to have serotonergic effects, so pethidine could, unlike most opioids, contribute to serotonin syndrome. Pethidine was the most widely used opioid in labor and delivery but has fallen out of favor in some countries such as the United States in favor of other opioids.

Demerol (meperidine) is a narcotic, or opioid, a pain medication that has been around for quite some time. It was once used frequently in hospital settings to treat moderate to severe pain and is still sometimes used prior to or during a surgical procedure to enhance the effects of anesthesia. However, the duration of Demerol's pain-relieving effects is shorter than other narcotics, and its production of toxic metabolites make it an inferior medication for pain control. Demerol also has a long list of potentially dangerous interactions with other medications. For these reasons, Demerol is now less frequently used to treat pain.

How It Works:
The pain relieving properties of Demerol differ from other medications, such as morphine because, instead of keeping nerve endings from transmitting messages of pain to the brain, Demerol acts on the central nervous system, essentially tricking the brain by replacing the feeling of pain with a "high." Patients who are given Demerol for pain are basically feeling the euphoric effects of the medication instead of their pain.

Demerol Pain Medication Information:
https://www.verywellhealth.com/demerol-pain-medication-uses-and-side-effects-1132345

Meperidine is used to relieve pain severe enough to require opioid treatment and when other pain medicines did not work well enough or cannot be tolerated. It belongs to the group of medicines called narcotic analgesics (pain medicines). Meperidine acts on the central nervous system (CNS) to relieve pain. This medicine 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.

Pediatric:
Appropriate studies have not been performed on the relationship of age to the effects of meperidine in the pediatric population.

Safety and efficacy have not been established.

Geriatric:
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of meperidine in the elderly. However, elderly patients are more likely to have age-related kidney, liver, or lung problems, which may require caution and an adjustment in the dose for patients receiving meperidine.

Other Interactions:

• Ethanol
• Grapefruit Juice

Other Medical Problems:
Make sure you tell your doctor if you have any other medical problems, especially:

• Addison disease (adrenal gland problem)
• Alcohol abuse, or history of
• Brain problems (including tumors or increased intracranial pressure)
• Breathing or lung problems (eg, COPD, hypoxia, sleep apnea)
• Central nervous system (CNS) depression
• Cor pulmonale (serious heart condition)
• Drug dependence, especially with narcotics, or history of
• Enlarged prostate
• Gallbladder disease
• Head injuries, history of
• Hypothyroidism (an underactive thyroid)
• Kyphoscoliosis (severe curvature of the spine with breathing problems)
• Mental illness, history of
• Pancreatitis (swelling of the pancreas)
• Pheochromocytoma (adrenal gland tumor)
• Sickle cell anemia (inherited blood disorder)
• Weakened physical condition - Use with caution. May increase risk for more serious side effects

• Heart rhythm problems (eg, atrial flutter, tachycardia)
• Hypotension (low blood pressure)
• Hypovolemia (low blood volume)
• Seizures, history of - Use with caution. May make these conditions worse

• Kidney disease
• Liver disease - Use with caution. The effects may be increased because of slower removal of the medicine from the body

• Lung or breathing problems (eg, asthma, respiratory depression), severe
• Stomach or bowel blockage (eg, paralytic ileus) - Should not be used in patients with these conditions

Meperidine (Oral Route) (Demerol | Meperitab):
https://www.mayoclinic.org/drugs-supplements/meperidine-oral-route/description/drg-20074223

Meperidine: Friend or Foe?
Meperidine was synthetically derived in 1939 as an anticholinergic agent, but was discovered to possess analgesic properties shortly after. Although it's a weak agonist at the mu opioid receptor, anecdotal evidence suggested it was a good alternative to morphine because it circumvented morphine's most common adverse effects, specifically respiratory depression and chemical dependency. However, clinical experience has taught us differently.

(2016) Meperidine: Friend or Foe?:
https://www.pharmacytimes.com/contributor/orlando-alvarado-rivera-pharmd-ms/2016/09/meperidine-friend-or-foe

(2002 Article) Meperidine for pain:
Until recently, MP was the most commonly prescribed drug for post-operative pain, largely by the IM route, ordered prn at a q4-6 dosing interval. Since physicians largely learned how to manage pain from their experiences with surgical patients, MP was the parenteral opioid physicians were most familiar with, ergo, the opioid they typically used for any severe pain problem. However, due to its relatively low potency, short duration of action, and toxic metabolite (see below), MP is a poor analgesic choice. Over 20 years ago, it became widely recognized that continued MP administration over several days leads to a syndrome of CNS excitation, with tremors, myoclonus, delirium, and seizures. This syndrome, due to accumulation of the metabolite normeperidine, is more prevalent in the elderly or in patients with renal dysfunction.

MP was established in medical lore as the drug of choice for certain pain conditions, notably pancreatitis / biliary colic and sickle cell pain. In fact, there is little data supporting the contention that MP is the drug of choice for pancreatitis. A recent review of opioid effect on biliary pressure found contradictory results from in vivo biliary manometry studies and only anecdotal reports documenting significant clinical impact. Recent consensus reports on sickle cell pain have specifically recommended not using MP, due to its short duration and toxic metabolite. What are the recommendations? Every national pain management Clinical Practice Guideline published since 1990 has advised that parenteral MP is not appropriate for a) long-term use (beyond several days), b) any chronic pain syndrome, c) the elderly or d) patients with renal dysfunction. The American Pain Society recommends meperidine should not be used for more than 48 hours for acute pain in patients without renal or CNS disease, or at doses greater than 600 mg/24 hours, and should not be prescribed for chronic pain. In view of all the national guidelines, some hospitals have removed MP from their formulary, others restrict use to short-term, procedure related analgesia (e.g. bone marrow biopsy, colonoscopy).

What is the bottom line? There is little rationale for prescribing parenteral MP and no justification for using oral MP. Parenteral MP is a reasonable choice only when a) there is intolerance to all other opioids and/or b) very brief analgesia is needed.

(2002) Meperidine for pain: what is all the fuss?
https://www.mywhatever.com/cifwriter/library/eperc/fastfact/ff71.html

(2006) Is Demerol the best pain reliever?
One of the most commonly used opioid analgesics on the market is meperidine (DEMEROL). Eisendrath, et al., claimed in 1987 that meperidine was the most widely used opioid analgesic in the US, prescribed by approximately 60% of physicians for acute pain and by 22% for chronic pain. Of the top 10 drugs mentioned by general surgeons in 2004, based on projected data from a survey of general surgeons, Demerol injection was third on the list.

Given the reports in the literature, its potential for seizures, its effects on the central nervous system, and its anticholinergic effect, meperidine may not be the optimal analgesic for the treatment of pain. The euphoric effects are reported to be more pronounced than with other analgesic agents, and it is the only agent associated with negative effects on mood. It has been shown to be a less effective analgesic than other agents with a capacity to cover mild to moderate pain. Since other opioid agonist analgesics have similar analgesic efficacy, lower risk of neurotoxicity at usual therapeutic doses, and lower risk for Serotonin Syndrome due to drug interactions, your facility may want to consider limiting the use of meperidine to those situations in which the benefits outweigh the risks.

"Demerol is an old, lumbering dinosaur which must be taken out of use in order that effective pain control can become a reality." - Dr. J. Davis Daniels

(2006) Demerol: Is It the Best Analgesic? http://patientsafety.pa.gov/ADVISORIES/Pages/200606_18.aspx

Meperidine (Demerol) Safety Issues:
(2005) There is a move in hospitals to restrict the use of meperidine as a result of adverse events such as neurotoxicity from the normeperidine metabolite, delirium in elderly patients, and serotonin syndrome. Repeated administration of meperidine can lead to an accumulation of normeperidine and predispose patients to neurotoxicity. It has been shown that meperidine is poorly tolerated in the elderly and is the narcotic most often associated with deliriumin the geriatric surgical population. Meperidine can predispose patients to delirium due to its anticholingeric properties, and the risk of normeperidine neurotoxicity with renal function changes with age.

Meperidine possesses complex pharmacodynamics not found with first-line opioids including the inhibition of the re-uptake of the neurotransmitter serotonin. This can lead to serotonin syndrome condition that presents with mental status changes, myoclonus,muscle rigidity, tremors, diaphoresis, and hyper-reflexia. Itoccurs as a result of excessive serotonin levels, usually resulting from interactions between drugs that increase serotonin levels. Meperidine does not possess many of the ideal characteristics of an opioid for administration in critical care. A stated allergy to morphine (or other opiates) may lead to meperidine use. Conclusion: The use of meperidine in pain management should be restricted, and careful evaluation of the risk-benefit ratio should be made before it is used in any critically ill patient.

(2005) Meperidine (Demerol) safety issues (PDF 5 pages):
https://www.ismp-canada.org/download/caccn/CACCN-Spring05.pdf

Pethidine, also known as meperidine and Demerol, a narcotic analgesic that can be used for the relief of most types of moderate to severe pain, including postoperative pain and the pain of labor. Meperidine is an opioid agonist with multiple actions qualitatively similar to those of morphine. Most common adverse reactions were lightheadedness, dizziness, sedation, nausea, vomiting, and sweating. Pethidine has serious interactions that can be dangerous with monoamine oxidase inhibitors (e.g., furazolidone, isocarboxazid, moclobemide, phenelzine, procarbazine, selegiline, tranylcypromine). Pethidine can interact with muscle relaxants, some antidepressants, benzodiazepines, and ethanol.

Pethidine:
https://drugs.ncats.io/drug/9E338QE28F

Important Information:

MISUSE OF OPIOID MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medication in a place where others cannot get to it.

Using opioid medicine during pregnancy may cause life-threatening withdrawal symptoms in the newborn.

Fatal side effects can occur if you use opioid medicine with alcohol, or with other drugs that cause drowsiness or slow your breathing.

Do not drink alcohol. Dangerous side effects or death can occur when alcohol is combined with meperidine.

Avoid driving or hazardous activity until you know how meperidine will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

Interactions:

Drug Interactions (405) Alcohol/Food Interactions (1) Disease Interactions (17)

What other drugs will affect Meperidine?
You may have breathing problems or withdrawal symptoms if you start or stop taking certain other medicines. Tell your doctor if you also use an antibiotic, antifungal medication, heart or blood pressure medication, seizure medication, or medicine to treat HIV or hepatitis C. Opioid medication can interact with many other drugs and cause dangerous side effects or death. Be sure your doctor knows if you also use:

• other narcotic medications - opioid pain medicine or prescription cough medicine
• a sedative like:
  • Valium - diazepam
  • alprazolam
  • lorazepam
  • Xanax
  • Klonopin
  • Versed
  • others
• drugs that make you sleepy or slow your breathing - a sleeping pill, muscle relaxer, medicine to treat mood disorders or mental illness
• drugs that affect serotonin levels in your body - a stimulant, or medicine for depression, Parkinson's disease, migraine headaches, serious infections, or nausea and vomiting

This list is not complete. Other drugs may affect meperidine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.

A total of 405 drugs are known to interact with Meperidine.

• 154 major drug interactions
• 248 moderate drug interactions
• 3 minor drug interactions

Meperidine Information:
https://www.drugs.com/mtm/meperidine.html

Liver:
Meperidine has not been linked to serum enzyme elevations during therapy or to clinically apparent liver injury.

Meperidine Hepatotoxicity:
Therapy with meperidine has not been linked to serum enzyme elevations. There have been no convincing cases of idiosyncratic acute, clinically apparent liver injury attributed to meperidine.

Meperidine Overview:
https://www.ncbi.nlm.nih.gov/books/NBK548764/

Pain:
Meperidine is not recommended as a first choice analgesic by The American Pain Society and ISMP (2007); if no other options, limit use in acute pain to 48hr; doses should not exceed 600 mg/24hr; oral route is not recommended for treatment of acute or chronic pain

Demerol, pethidine (meperdine) (Rx)

Black Box Warnings:
Meperidine (Rx): https://reference.medscape.com/drug/demerol-meperidine-343315
Opioid analgesic risk evaluation and mitigation strategy (REMS) To ensure that benefits of opioid analgesics outweigh risks of addiction, abuse, and misuse, the Food and Drug Administration (FDA) has required a REMS for these products; under requirements of the REMS, drug companies with approved opioid analgesic products must make REMS-compliant education programs available to healthcare providers Healthcare providers are strongly encouraged to: Complete a REMS-compliant education program Counsel patients and/or their caregivers, with every prescription, on safe use, serious risks, storage, and disposal of these products Emphasize to patients and their caregivers the importance of reading the Medication Guide every time it is provided by their pharmacist Consider other tools to improve patient, household, and community safety Addiction, abuse, and misuse Risk of opioid addiction, abuse, and misuse, which can lead to overdose and death; assess each patient's risk prior to prescribing and monitor all patients regularly for the development of these behaviors or conditions Life-threatening respiratory depression Serious, life-threatening, or fatal respiratory depression may occur Monitor for respiratory depression, especially during initiation or following a dose increase Neonatal opioid withdrawal syndrome Prolonged use 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 Interactions with Drugs Affecting Cytochrome P450 Isoenzymes Concomitant use with cytochrome P450 3A4 inhibitors or discontinuation of inducers can result in fatal overdose of meperidine Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death; reserve concomitant prescribing for use in patients for whom alternative treatment options are inadequate; limit dosages and durations to minimum required; follow patients for signs and symptoms of respiratory depression and sedation Concomitant Use of Meperidine with Monoamine Oxidase (MAO) Inhibitors Concomitant use of with Monoamine oxidase (MAO) inhibitors can result in coma, severe respiratory depression, cyanosis and hypotension; use with MAO inhibitors is contraindicated Accidental ingestion Accidental ingestion especially by children, can result in a fatal overdose Risk of Medication Errors Ensure accuracy when prescribing, dispensing, and administering oral solution; dosing errors due to confusion between mg and mL, and other oral solutions of different concentrations can result in accidental overdose and death

Drug Dependence:
Meperidine can produce drug dependence of the morphine type and therefore has the potential for being abused. Psychic dependence, physical dependence, and tolerance may develop upon repeated administration of meperidine, and it should be prescribed and administered with the same degree of caution appropriate to the use of morphine.

Drug Interactions:
Interactions with other CNS Depressants: Meperidine should be used with great caution and in reduced dosage in patients who are concurrently receiving other narcotic analgesics, general anesthetics, phenothiazines, other tranquilizers (see Dosage), sedative-hypnotics (including barbiturates), tricyclic antidepressants, and other CNS depressants (including alcohol). Respiratory depression, hypotension, and profound sedation or coma may result.

Demerol (Meperidine):
https://www.rxmed.com/b.main/b2.pharmaceutical/b2.1.monographs/cps-_monographs/CPS-_(General_Monographs-_D)/DEMEROL.html

Abuse:
Demmies = Slang for Demerol. Demerol was is used in the short-term treatment of severe pain and may be used during surgery or to ease the pain of labor and delivery during childbirth. Demerol provides users with an extreme sense of euphoria and calm, and these pleasurable effects make it more likely to be abused. Not all individuals set out to misuse Demerol and other opioid drugs. Many people find that they enjoy the pleasurable effects these drugs create and end up taking the prescription in ways they did not intend to. Demerol abuse may not always be obvious, but there are several physical signs of abuse to look for. Long-term abuse of Demerol may also result in serious psychological and physical harm. Even when prescription opioids such as Demerol are used as prescribed by a doctor, they may cause physical and psychological dependence or addiction. If a person suddenly stops taking Demerol after weeks or months of abuse, he or she will experience uncomfortable physical withdrawal symptoms.

Demerol (Meperidine) Addiction - Side Effects, Abuse, Detox and Withdrawal:
https://novarecoverycenter.com/drugs/demerol/

Is Meperidine Addictive?
Meperidine is used for the treatment of moderate-to-severe pain, and it's sometimes used to put people to sleep before a procedure or for pain relief following childbirth. Meperidine is an opioid analgesic, meaning it's an opioid pain medication that binds to certain opioid receptor sites throughout the body of the patient. Opioids are also referred to as narcotics. Meperidine is a synthetic opioid, which was first synthesized in the late 1930s. As with other opioids, meperidine changes how the brain and the nervous system send pain signals and respond to pain. Meperidine is available as a tablet and a syrup, and it's taken as needed. Some of the side effects of meperidine can include nausea, vomiting, constipation, dry mouth, sweating and changes in vision. Severe side effects may occur as well, including slow or labored breathing. Meperidine is similar to morphine. When someone is prescribed meperidine or given the drug in a clinical or hospital setting, they should be warned about the risk of addiction. There is a black box warning with meperidine, stating that it may be habit-forming, especially with longer-term use.

Meperidine is a synthetic opioid. Opioids are a class of drugs that include prescription narcotic pain medicines and the illicit drug heroin. Opioids contain chemicals that relieve pain and create relaxation, so they are often used in medicine, but they are highly addictive. When someone takes a prescription medicine like meperidine as prescribed and only for a short time, the risk of addiction is somewhat low, but misusing any opioid can increase the likelihood of an addiction forming as well as other dangerous side effects. Opioids activate receptors located through the brain, spinal cord and all of the body. These receptor sites are involved not only in pain sensations but also feelings of pleasure. When opioids bind to receptor sites, they block pain signals being sent from the body to the brain, but they can also create a pleasurable or euphoric response. An artificially high amount of dopamine is released into the brain and body. That can create a reward and reinforcement response, which can then cause addiction.

Meperidine Addiction:
https://www.therecoveryvillage.com/meperidine-addiction/#gref

Meperidine Potency:
Meperidine is a synthetic narcotic analgesic which acts on the central nervous system by a mechanism that is similar to Morphine, although with a shorter duration of action. Meperidine has approximately one tenth the potency of Morphine and tolerance to Meperidine develops more slowly. It is used to treat moderate to severe pain, producing clinical effects of analgesia, sedation, euphoria, and respiratory depression.

Meperidine Homogeneous Enzyme Immunoassay (HEIA) (PDF 2 pages):
https://immunalysis.com/wp-content/uploads/2014/05/05_MKT-1013-Meperidine-Factsheet-Ver.-B.pdf

Potency:
Many of its pharmacologic properties and indications are similar to those of morphine, but meperidine has no effect on cough and is much less constipating. It is 1/8 as potent as morphine on a weight basis when administered parenterally. Meperidine is about 1/3 to 1/4 as potent orally as parenterally. Meperidine is preferred to morphine for obstetric use because its rapid onset of action and shorter duration usually permit greater flexibility in maternal analgesia, possibly with less effect on neonatal respiration. Nevertheless, it can produce significant respiratory depression in the newborn infant proportional to the fetal blood concentration. This can be minimized by giving small incremental doses of 25 mg intravenously during labor. The maximal analgesic effect occurs 30 to 50 minutes after intramuscular injection. The duration of action (two to four hours) is shorter than that of morphine.

Meperidine, Serum or Plasma:
https://www.labcorp.com/test-menu/31036/meperidine-serum-or-plasma

Meperidine Poor Oral Bioavailability:
Other pharmacological challenges with this medication is the poor bioavailability with oral use (around 40-60%) and of what escapes first pass metabolism, only 40% ofexists as free drug available for pharmacological efficacy. It is no surprise then that in research, oral meperidine has very poor analgesic efficacy (~10 times lower than morphine). Another concern and contributor of serious overdose is the high oral: parenteral conversion ratio for reasons described. Parenteral use is associated with an even lower duration of action and as such the frequent injections required can cause dystrophy and increase the risk of infections.

Meperidine (Demerol) a relic misfit for chronic pain (PDF 4 pages):
http://www.cpsa.ca/wp-content/uploads/2016/08/Clinical-Toolkit-Mepridine-A-Relic-Misfit-for-Chronic-Pain.docx.pdf?x91570

Meperidine Side Effects:
Its effects are felt within 15 minutes and last from 3 to 5 hours. Meperidine is used to relieve pain during childbirth, although it may slow the respiratory rate of both mother and infant. The drug also may be used as an aid in preoperative sedation and anesthesia. Side effects include drowsiness, lightheadedness, dryness of the mouth, weakness, and nausea. Meperidine is highly addictive; however, its side effects tend to be less severe than those of morphine, making it a preferable choice in many instances.

Meperidine Drug:
https://www.britannica.com/science/meperidine

Breastfeeding:

Summary of Use During Lactation:
Other agents are preferred over meperidine during breastfeeding.

Intravenous meperidine during labor can interfere with nursing and maternal use of meperidine during breastfeeding can sedate the infants.

Patient-controlled epidural analgesia postpartum appears to be free from these effects. However, other agents, such as Fentanyl, are preferred for intravenous or intramuscular use, especially while nursing a newborn or preterm infant.

Labor pain medication may delay the onset of lactation.

A single dose for anesthesia or conscious sedation usually does not cause problems in older breastfed infants.

When a combination of anesthetic agents is used for a procedure, follow the recommendations for the most problematic medication used during the procedure.

Maternal use of oral narcotics during breastfeeding can cause infant drowsiness, central nervous system depression and even death.

Newborn infants seem to be particularly sensitive to the effects of even small dosages of narcotic analgesics. Once the mother's milk comes in, it is best to provide pain control with a nonnarcotic analgesic and limit maternal intake of meperidine to a few days at a low dosage with close infant monitoring.

If the baby shows signs of increased sleepiness (more than usual), difficulty breastfeeding, breathing difficulties, or limpness, a physician should be contacted immediately.

Drug Levels:
Meperidine is metabolized to the inactive meperidinic acid and to the active metabolite normeperidine which has half the analgesic activity and at least twice the central nervous system excitatory activity of meperidine.

The oral bioavailability of meperidine is about 50% in adults.

Newborns have impaired meperidine metabolism and possibly a higher oral bioavailability than adults.

Newborns may also experience more central nervous system depression from normeperidine than adults. The usual infant oral meperidine dose is 1 to 2 mg/kg while the usual intravenous dose is 1 mg/kg which results in neonatal plasma levels of about 200 to 500 mcg/L.

Effects on Lactation and Breastmilk:

Meperidine can increase serum prolactin.

However, the prolactin level in a mother with established lactation may not affect her ability to breastfeed. More importantly, meperidine is likely to interfere with infant nursing behavior when given during labor.

Alternate Drugs to Consider:

• Acetaminophen
• Butorphanol
• Fentanyl
• Hydromorphone
• Morphine

Meperidine Drug Levels and Effects:
https://www.ncbi.nlm.nih.gov/books/NBK501232/

Pregnancy and Lactation:
Prolonged use of opioid analgesics such as meperidine during pregnancy for medical or nonmedical purposes can result in physical dependence in neonate and neonatal opioid withdrawal syndrome shortly after birth. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and the rate of elimination of drug by newborn. Observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly. Meperidine appears in milk of nursing mothers receiving the drug. The developmental and health benefits of breastfeeding should be considered along with mother's clinical need for therapy and any potential adverse effects on breastfed infant or from underlying maternal condition.

Demerol (meperdine)

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.
RxList
Meperidine Article: https://www.rxlist.com/consumer_meperidine_demerol/drugs-condition.htm
Opioid medicine can slow or stop your breathing, and death may occur. 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: slow heartbeats, weak or shallow breathing, breathing that stops during sleep severe drowsiness, feeling like you might pass out confusion, mood changes severe constipation tremors, muscle movements you cannot control, or a seizure (convulsions) 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.
Serious side effects may be more likely in older adults and those who are malnourished or 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 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.

Overdose:
Meperidine hydrochloride overdose occurs when someone takes more than the normal or recommended amount of this medicine. This can be by accident or on purpose. Meperidine can be harmful in large amounts. A severe overdose of meperidine can cause death. Seek medical help right away. Do NOT make the person throw up unless poison control or a health care provider tells you to.

Meperidine Hydrochloride Overdose:
https://www.mountsinai.org/health-library/poison/meperidine-hydrochloride-overdose

Erowid Experience Vault:
https://erowid.org/experiences/subs/exp_Pharms_Meperidine.shtml

Prescribed for:

What Conditions does it Treat?

• Excessive pain
• Acute pain

Uses:
Meperidine is used to help relieve moderate to severe pain. It belongs to a class of drugs known as opioid analgesics and is similar to morphine. It works in the brain to change how your body feels and responds to pain.

Meperidine should not be used to treat long-term or ongoing pain. It should only be used to treat sudden episodes of moderate to severe pain.

Before using:
Tell your doctor or pharmacist your medical history, especially of:

• Brain disorders (such as head injury, tumor, seizures)
• Breathing problems (such as asthma, sleep apnea, chronic obstructive pulmonary disease-COPD)
• Gallbladder disease
• Kidney disease
• Liver disease
• Mental/mood disorders (such as confusion, depression, thoughts of suicide)
• Personal or family history of a substance use disorder (such as overuse of or addiction to drugs/alcohol)
• Stomach/intestinal problems (such as blockage, constipation, diarrhea due to infection, paralytic ileus)
• Disease of the pancreas (pancreatitis)
• Difficulty urinating (such as due to enlarged prostate)
• Pheochromocytoma
• Heart problems (such as fast/irregular heartbeat)
• Sickle cell anemia

Precautions:
Meperidine is usually used only for a short time.

Repeated or high doses may cause drug levels to build up in the body and cause serious side effects such as seizures and shaking. Caution is advised if this medication is used for conditions that require long-term or high-dosage treatment (such as sickle cell anemia, burns, cancer). Consult your doctor or pharmacist for details.

• This drug may make you dizzy or drowsy
• Alcohol or marijuana (cannabis) can make you more dizzy or drowsy
• Do not drive, use machinery, or do anything that needs alertness until you can do it safely
• Avoid alcoholic beverages.
• Talk to your doctor if you are using marijuana (cannabis).

WARNINGS:

Meperidine has a risk for abuse and addiction, which can lead to overdose and death.

Meperidine may also cause severe, possibly fatal, breathing problems.

To lower your risk, your doctor should have you take the smallest dose of meperidine that works, and take it for the shortest possible time.

The risk for severe breathing problems is higher when you start this medication and after a dose increase, or if you take the wrong dose/strength.

Taking this medication with alcohol or other drugs that can cause drowsiness or breathing problems may cause very serious side effects, including death.

Also, other medications can affect the removal of meperidine from your body, which may affect how meperidine works. Be sure you know how to take meperidine and what other drugs you should avoid taking with it.

Get medical help right away if any of these very serious side effects occur: slow/shallow breathing, unusual lightheadedness, severe drowsiness/dizziness, difficulty waking up.

User Reviews:

26 Total User Reviews

Meperidine Oral: Read Reviews
Condition: Pain (26 Reviews):
		Effectiveness	(4.20)	★★★★★ ★★★★★
		Ease of Use	(4.35)	★★★★★ ★★★★★
		Satisfaction	(4.15)	★★★★★ ★★★★★

Meperidine HCL (Demerol):
https://www.webmd.com/drugs/2/drug-4055/meperidine-oral/details

What other drugs will affect meperidine?
Opioid medication can interact with many other drugs and cause dangerous side effects or death. Be sure your doctor knows if you also use:

• Other narcotic medications - opioid pain medicine or prescription cough medicine
• A sedative like Valium
• Drugs that make you sleepy or slow your breathing - a sleeping pill, muscle relaxer, medicine to treat mood disorders or mental illness
• Drugs that affect serotonin levels in your body - a stimulant, or medicine for depression, Parkinson's disease, migraine headaches, serious infections, or nausea and vomiting.

Meperidine (Demerol, Demerol HCl) Information:
https://www.emedicinehealth.com/drug-meperidine/article_em.htm

What is the most important information I should know about meperidine?

• You should not use meperidine if you have severe asthma or breathing problems.
• Do not use this medicine if you have used an MAO inhibitor in the past 14 days.
• Meperidine can slow or stop your breathing, and may be habit-forming.
• MISUSE OF THIS MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription.
• Taking this medicine during pregnancy may cause life-threatening withdrawal symptoms in the newborn.
• Fatal side effects can occur if you use this medicine with alcohol, or with other drugs that cause drowsiness or slow your breathing.

https://www.cigna.com/individuals-families/health-wellness/hw/medications/meperidine-d00017a1

IMPORTANT WARNING:
Meperidine may be habit forming, especially with prolonged use. Take meperidine exactly as directed. Do not take more of it, take it more often, or take it in a different way than directed by your doctor. Meperidine may cause serious or life-threatening breathing problems, especially during the first 24 to 72 hours of your treatment and any time your dose is increased. Your doctor will monitor you carefully during your treatment. Tell your doctor if you have or have ever had slowed breathing or asthma. Taking certain medications during your treatment with meperidine may increase the risk that you will develop serious or life-threatening breathing problems, sedation, or coma. Do not drink alcohol, take prescription or nonprescription medications that contain alcohol, or use street drugs during your treatment.

Meperidine Information:
https://medlineplus.gov/druginfo/meds/a682117.html

Demerol Injectable (meperidine hydrochloride)

Maximum Dosage:
Prescribers Digital Reference
Meperidine Hydrochloride Drug Summary: https://www.pdr.net/drug-summary/Demerol-Injectable-meperidine-hydrochloride-688
Adults	150 mg/dose PO, IV, IM, or subcutaneously for pain; 100 mg/dose IM or subcutaneously for preoperative procedural sedation.
Geriatric	150 mg/dose PO, IV, IM, or subcutaneously for pain; 100 mg/dose IM or subcutaneously for preoperative procedural sedation.
Adolescents	1.8 mg/kg/dose (Max: 150 mg/dose) PO, IV, IM, or subcutaneously for pain; 2.2 mg/kg/dose (Max: 100 mg/dose) IM or subcutaneously for preoperative procedural sedation.
Children	1.8 mg/kg/dose (Max: 150 mg/dose) PO, IV, IM, or subcutaneously for pain; 2.2 mg/kg/dose (Max: 100 mg/dose) IM or subcutaneously for preoperative procedural sedation.
Infants	Safety and efficacy have not been established.
Neonates	Safety and efficacy have not been established.

Meperidine HCL Cartridge:
https://www.webmd.com/drugs/2/drug-5598/meperidine-injection/details

Demerol Prescribing Information (PDF 30 pages):
https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/005010s055lbl.pdf

DEMEROL- meperidine hydrochloride injection Prescribing Information:
http://labeling.pfizer.com/ShowLabeling.aspx?id=4516

Meperidine (hydrochloride) CRM Safety Data Sheet (PDF 7 pages):
https://www.caymanchem.com/msdss/19406m.pdf

Meperidine is a synthetic opiate agonist belonging to the phenylpiperidine class. Meperidine may produce less smooth muscle spasm, constipation, and depression of the cough reflex than equivalent doses of morphine. The onset of action is lightly more rapid than with morphine, and the duration of action is slightly shorter. The chemical structure of meperidine is similar to local anesthetics. Meperidine is recommended for relief of moderate to severe acute pain and has the unique ability to interrupt postoperative shivering and shaking chills induced by amphotericin B. Meperidine has also been used for intravenous regional anesthesia, peripheral nerve blocks and intraarticular, epidural and spinal analgesia. Meperidine is considered a second-line agent for the treatment of acute pain.

A precursor to the opioid analgesic drug pethidine (meperidine). It is not known to have any analgesic activity in its own right, however other derivatives of pethidine with a 4-cyano group in place of the carboxylate ethyl ester have been found to be active, so pethidine intermediate A might also show opioid effects.

Pethidine is quickly hydrolysed in the liver to pethidinic acid and is also demethylated to norpethidine, which has half the analgesic activity of pethidine but a longer elimination half-life (8-12 hours); accumulating with regular administration, or in renal failure. Norpethidine is toxic and has convulsant and hallucinogenic effects. The toxic effects mediated by the metabolites cannot be countered with opioid receptor antagonists such as naloxone or naltrexone and are probably primarily due to norpethidine's anticholinergic activity probably due to its structural similarity to atropine though its pharmacology has not been thoroughly explored. The neurotoxicity of pethidine's metabolites is a unique feature of pethidine compared to other opioids. Pethidine's metabolites are further conjugated with glucuronic acid and excreted into the urine.

Metabocard for Normeperidine:
http://www.hmdb.ca/metabolites/HMDB0041958

Normeperidine (hydrochloride) Safety Data Sheet (PDF 5 pages):
https://www.caymanchem.com/msdss/15285m.pdf

4-phenylpiperidine derivative that is both a precursor to, and the toxic metabolite of, pethidine (meperidine). Norpethidine acts as a stimulant and causes convulsions. Build up of norpethidine is a major complication when pethidine is used in medicine as an analgesic, as when pethidine is used in high doses or administered by intravenous infusion, norpethidine can accumulate in the body at a faster rate than it is being excreted, particularly in elderly patients or those with compromised liver or kidney function, resulting in a range of toxic effects, mainly convulsions, but also myoclonus and hyponatremia. These complications can be serious and have sometimes resulted in death.

A 4-phenylpiperidine derivative that is both a metabolite of and a precursor to pethidine (meperidine). Pethidinic acid is a controlled drug because of its potential uses in manufacturing both pethidine itself and some of its substituted derivatives, but it has little opioid activity in its own right. Metabolism of pethidine to pethidinic acid is carried out mainly by the carboxylesterase enzyme hCE-1 in the liver, and since the activity of this enzyme can vary between individuals, the rate and extent of pethidinic acid production can vary.

Benzethidine an opioid analgesic that was forbidden for use.

Benzethidine:
https://drugs.ncats.io/drug/X0I74BAR02

This compound belongs to the class of organic compounds known as phenylpiperidines. These are compounds containing a phenylpiperidine skeleton, which consists of a piperidine bound to a phenyl group.

Related to the clinically used opioid analgesic drug pethidine (meperidine, or Demerol). Benzethidine is not currently used in medicine.