Opioids meperidine

Analgesics are given to reduce abdominal pain. In the past, parenteral meperidine (50 to 100 mg) every 3 to 4 hours was usually used because it causes less spasm of the sphincter of Oddi than other opioids. Meperidine is used less frequently today because it is not as effective as other opioids and is contraindicated in renal failure. Parenteral morphine is sometimes used, but it is thought to cause spasm of the sphincter of Oddi, increases in serum amylase and, rarely, pancreatitis. Hydromorphone may also be... 

Spasmolytics. N-Butylscopolamine (p. 104) is used for the relief of painful spasms of the biliary or ureteral ducts. Its poor absorption (N.B. quaternary N absorption rate <10%) necessitates parenteral administration. Because the therapeutic effect is usually weak, a potent analgesic is given concurrently, e.g., the opioid meperidine. Note that some spasms of intestinal musculature can be effectively relieved by organic nitrates (in biliary colic) or by nifedipine (esophageal hypertension and achalasia). 

Semi-synthetic and synthetic opioids (meperidine, hydrocodone, fentanyl, etc.) are the result of many attempts to produce effective yet safer analgesics. The fact that both morphine and codeine are still widely used indicates that the newer opioids have been only moderately successful. However, current knowledge of the opioid system makes the goal of producing the perfect... 

As with all opioids, meperidine is capable of producing euphoria. A few people may get a mild stimulant effect and a feeling of elation. However, instead of euphoria after a meperidine dose, some people report a feeling of dysphoria—a general feeling of discomfort and restlessness—or even disorientation and confusion. Still other people may just feel drowsy, with no noticeable positive or negative effect on their mood. 

Peak respiratory depression is observed within 1 hour of intramuscular administration, and there is a return toward normal starting in about 2 hours. Like other opioids, meperidine causes pupillary constriction, increases the sensitivity of the labyrinthine apparatus, and has effects on the secretion of pituitary hormones similar to those of morphine. Meperidine sometimes causes CNS excitation, characterized by tremors, muscle twitches, and seizures these effects are due largely to accumulation of a metabolite, normeperidine. As with morphine, respiratory depression is responsible for an accumulation of CO2 which, in turn, leads to cerebrovascular dilation, increased cerebral blood flow, and elevation of cerebrospinal fluid pressure. 

Morphine is the prototype of the strong opioids. Meperidine is a variant used commonly for analgesia. Methadone is a strong agonist used in maintenance programs for patients addicted to opioids. Codeine, oxycodone, and hydrocodone are moderate agonists, whereas propoxyphene is a weak agonist. 

Tramadoi produces anaigesia by an opioid effect and by the enhancement of serotonergic and adrenergic pathways. The phenyipiperidine series of opioids (meperidine, tramadoi, methadone, fentanyi, D-propoxyphene) are very weak serotonin reuptake inhibitors. 

Opiates 2-3 days Synthetic opioids (meperidine, methadone, propoxyphene, oxycodone) are Bof detected separate testing for methadone is sometimes offered, (see also Table 1-33)... 

A quick perusal of the two-dimensional structures of a range of important opioid drugs reveals that while many of the clinically relevant compounds show clear structural similarities to morphine (Table 8.2), such similarities are not immediately obvious with some other widely used drugs such as the synthesized, and structurally flexible, opioids meperidine (pethidine). 

The search for opioid analgesics which show reduced addiction liability ha.s centered largely on benzomorphan and morphinan derivatives. Some research has, however, been devoted to derivatives of the structurally simpler meperidine series. The preparation of one such compound, picenadol (59), starts with the reaction of N-methyl-4-piperidone with the lithium derivative from m-methoxybromobenzene. Dehydration of the first formed carbinol 51 gives the intermediate 52. Deprotonation by means of butyl lithium gives an anion which can be depicted in the ambident form 53. In the event, treatment of the anion with propyl bromide gives the product 54 from reaction of the benzylic anion. Treatment of that product, which now contains an eneamine function. 

Morphine, when extracted from raw opium and treated chemically, yields the semisynthetic narcotics hydromorphone, oxymorphone, oxycodone, and heroin. Heroin is an illegal narcotic in the United States and is not used in medicine. Synthetic narcotics are those man-made analgesics with properties and actions similar to the natural opioids. Examples of synthetic narcotic analgesics are methadone, levorphanol, remifen-tanil, and meperidine Additional narcotics are listed in the Summary Drug Table Narcotic Analgesics. 

Opioids. Reactions to morphine, codeine phosphate, meperidine, fentanyl and its derivatives are uncommon. Because of their direct histamine-releasing properties, especially regarding morphine and codeine, distinction between anaphylaxis and non-immune-mediated histamine release is not always easy. Only 12 cases were recorded in the last 2 years epidemiologic survey in France, 9 of them being related to morphine administration [9]. 

True narcotic allergies are rare and should not be confused with pruritus associated with opiate use. Cross-sensitivity between morphine-like, meperidine-like, and methadone-like agents is unlikely. Therefore, when an individual is allergic to one drug in a chemical class of opioids, it is reasonable to select... 

Patients who are acutely intoxicated with an opioid usually present with miosis, euphoria, slow breathing and slow heart rate, low blood pressure, and constipation. Seizures may occur with certain agents such as meperidine (Demerol ). It is critically important to monitor patients carefully to avoid cardiac/ respiratory depression and death from an excessive dose of opioids. One strategy is to reverse the intoxication by utilizing naloxone (Narcan ) 0.4 to 2 mg IV every 2 to 3 minutes up to 10 mg. Alternatively, the IM/SC route may be used if IV access is not available. Because naloxone is shorter-acting than most abused opioids, it may need to be readministered at periodic intervals otherwise the patient could lapse into cardiopulmonary arrest after a symptom-free interval of reversed... 

Severe pain should be treated with an opioid such as morphine, hydromorphone, methadone, or fentanyl. Moderate pain can be treated effectively in most cases with a weak opioid such as codeine or hydrocodone, usually in combination with acetaminophen. Meperidine should be avoided owing to its relatively short analgesic effect and its toxic metabolite, normeperidine. Normeperidine may accumulate with repeated dosing and can lead to central nervous system side effects including seizures. 

The answer is e. (Hardmanr p 926.) Diphenoxylate is a piperidine opioid that is related to meperidine, it inhibits peristalsis and, hence, increases the passage time of the intestinal bolus. Lt is combined with atropine to discourage use as a street drug. Atropine has little effect on peristalsis. Clonidine, bismuth subsalicylate, and re hydration therapy are all useful in some types of diarrhea, but none of them inhibit peristalsis. 

The IV or IM administration of parenteral narcotics (meperidine, morphine, fentanyl) is commonly used to treat the pain associated with labor. Compared to epidural analgesia, parenteral opioids are associated with lower rates of oxytocin augmentation, shorter stages of labor, and fewer instrumental deliveries. 

Opioids and derivatives (e.g., meperidine, butorphanol, oxycodone, hydromorphone) provide effective relief of intractable migraine but should be reserved for patients with moderate to severe infrequent headaches in whom conventional therapies are contraindicated or as rescue medication after failure to respond to conventional therapies. Opioid therapy should be closely supervised. 

Both are classified as low-ceiling opioids (B), because neither is capable of eliciting the maximal analgesic effect obtained with morphine or meperidine. 

Meperidine Meperidine, the ethyl ester of l-methyl-4-phenylpiperidine-4-carboxyhc acid (3.1.39), is a synthetic opioid analgesic. Its synthesis is accomphshed by the alkylation of benzyl cyanide using Af,Al-fcix-(2-chlorethyl)-iV-methylamine in the presence of sodium amide, which forms l-methyl-4-phenyl-4-cyanopiperidine (3.1.38), and its subsequent acidic ethanolysis into meperidine [30-32]. 

Serotonin syndrome (sibutramine) The rare, but serious, constellation of symptoms also has been reported with the concomitant use of selective serotonin reuptake inhibitors and agents for migraine therapy (eg, sumatriptan, dihydroergotamine), certain opioids (eg, dextromethorphan, meperidine, pentazocine, fentanyl), lithium, or tryptophan. Because sibutramine inhibits serotonin reuptake, it should not be administered with other serotonergic agents. 

Pharmacology Pentazocine, a potent analgesic, weakly antagonizes the effects of morphine, meperidine, and other opiates at the p-opioid receptor. 

Pharmacology Diphenoxylate, a constipating meperidine congener, lacks analgesic activity. High doses cause opioid activity. 

Uses Obesity Action Blocks uptake of norepinephrine, serotonin, dopamine Dose 10 mg/d PO, may to 5 mg after 4 wk Caution [C, -] w/ SSRIs, Li, dextromethorphan, opioids Contra MAOI w/in 14 d, uncontrolled HTN, arrhythmias Disp Caps SE HA, insomnia, xerostomia, constipation, rhinitis, tach, HTN Interactions T Risk of serotonin synd W/ dextromethorphan, ergots, fentanyl, Li, meperidine, MAOIs, naratriptan, pentazocine, rizatriptan, sumatriptan, SSRIs, tryptophan, zolmitriptan, St. John s wort effects W/ cimetidine, erythromycin, ketoconazole T CNS depression W/ EtOH EMS Use fentanyl w/ caution, may T risk of serotonin synd concurrent EtOH use can T CNS depression OD May cause tach, HTN, diaphoresis, HA, fever, agitation, muscle tremors, and Szs symptomatic and supportive... 

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