Anesthetics morphine

Anesthetics morphine atroprine, and other mydriatrics Many alkylating agents naphthalene pesticides i.e.,... 

Opioids. Morphine [57-27-2] C yH NO, (8) the most prevalent and analgesicaHy potent of the naturally occurring opium alkaloids (qv), has been used as an anesthetic premedication for over one hundred years (93). It has also been used as an iv analgesic for the last four decades, and, since 1969, in high doses as an anesthetic agent (117). 

Morphine has certain undesirable side effects. Among these are respiratory depression, nausea, and vomiting, depression of the cough reflex, cardiovascular depression and hypotension, smooth muscle contraction (constipation), and histamine release (93). Morphine s onset of action, duration, and low therapeutic indices have prompted a search for a more effective opiate iv anesthetic. Extreme simplification of the complex morphine molecule has resulted in anilido —piperidines, the fentanyl class of extremely potent opiate iv anesthetics (118,119). 

The line of reasoning that leads from morphine to the 4-phenyl-piperidines is so clear—if unhistoric—as to demand exposition in an integral chapter. The chronologically oriented chapter on the development of the local anesthetics is included specifically to give the reader some appreciation of one of the first approaches to drug development. 

Many alkaloids have pronounced biological properties, and a substantial number of the pharmaceutical agents used today are derived from naturally occurring amines. As a few examples, morphine, an analgesic agent, is obtained from the opium poppy Papaver somnifemm. Cocaine, both an anesthetic and a central nervous system stimulant, is obtained front the coca bush Erythroxylon coca, endemic to upland rain forest areas of Colombia, Ecuador, Peru, Bolivia, and western Brazil. Reserpine, a tranquilizer and antihypertensive, comes from powdered roots of the semitropical plant Rauwolfia serpentina. Ephedrine, a bronchodilator and decongestant, is obtained front the Chinese plant Ephedra sinica. 

Sufentanil, fentanyl, remifentanil, alfentanil, and morphine sulfate should be administered only by those specifically trained in the use of IV and epidural anesthetics Oxygen, resusdtative, and intubation equipment should be readily available. 

Epidural analgesia is frequently used for lower extremity procedures and pain (e.g., knee surgery, labor pain, and some abdominal procedures). Intermittent bolus or continuous infusion of preservative-free opioids (morphine, hydromorphone, or fentanyl) and local anesthetics (bupivacaine) may be used for epidural analgesia. Opiates given by this route may cause pruritus that is relieved by naloxone. Adverse effects including respiratory depression, hypotension, and urinary retention may occur. When epidural routes are used in narcotic-dependent patients, systemic analgesics must also be used to prevent withdrawal since the opioid is not absorbed and remains in the epidural space. Doses of opioids used in epidural analgesia are 10 times less than intravenous doses, and intrathecal doses are 10 times less than epidural doses (i.e., 10 mg of IV morphine is equivalent to 1 mg epidural morphine and 0.1 mg of intrathecally administered morphine).45... 

Fentanyl was introduced to the United States in 1968 by the Janssen Pharmaceutical Company and marketed under the trade name Sublimaze. Its primary purpose was for use as an intravenous anesthetic and analgesic. It is 100 times more potent than morphine in reducing pain, and its duration of action is only 30 minutes (compared to morphine, which lasts several hours). Over the years, fentanyl has proved to be an extremely useful drug, and to date, it is still widely used for surgeries, childbirth, pain associated with cancer and other diseases, and the treatment of trauma-related injuries. Although fentanyl solutions are often given intravenously, pill forms of the drug are also available. 

Figure 7.3 The chemical structure of fentanyl and its illegal analogues alpha-methyl-fentanyl and 3-methyl-fentanyl are shown here. Fentanyl was originally designed and marketed as an anesthetic, as it is 100 times stronger than morphine.

Figure 7.4 The chemical structure of meperidine, its analogue MPPP, and the closely related neurotoxin MPTP, are all shown here. Meperidine, an anesthetic, was also used as an alternative to morphine. It proved advantageous because it has a shorter length of duration and fewer side effects than morphine.

Clinical reports of patients who underwent chloroform anesthesia indicated that premedication with morphine caused serious respiratory depression when chloroform was co-administered. Thiopentone (thiopental Na, an ultra-short-acting barbiturate anesthetic) was associated with increased incidences of hypotension in chloroform-anesthetized patients (Whitaker and Jones 1965). 

Open-heart st/rgeAy- Administer large doses (0.5 to 3 mg/kg) of morphine IV as the sole anesthetic or with a suitable anesthetic agent. The patients are given oxygen and cardiovascular function is not depressed by morphine, as long as adequate ventilation is maintained. Ml pain-8 to 15 mg administered parenterally. For very severe pain, additional smaller doses may be given every 3 to 4 hours as needed. Rectal - 10 to 30 mg every 4 hours as needed or as directed by physician. 

Levorphanol (Levo-Dromoran) is an L-isomer morphi-nan derivative of morphine that is five to seven times more potent than morphine. It produces all of the side effects associated with morphine but less nausea. It is indicated for moderate to severe pain as a preoperative anxiolytic. It is often used in combination with thiopental to reduce the latter drug s anesthetic dose and to decrease postoperative recovery time. The o-isomer of levorphanol, dextrorphan, does not possess opioid analgesic activity but is a useful antitussive. 

These drug products are used in a number of ways to treat various medical conditions, including the common cough, diarrhea, and pain. Surgeons and dentists also use morphine, the most important chemical substance within the opium poppy, as an anesthetic. Unfortunately, most opium is turned into heroin and ends up in the veins of addicts. 

Fentanyl is a semi-synthetic opioid, ft is a much more powerful version of morphine. Fentanyl is used during surgery as an anesthetic and is extremely dangerous when taken in a nonmedical context. First created in Belgium in the 1950s, fentanyl is 80 times more powerful than morphine. Due to its strength, fentanyl is listed as a Schedule I narcotic in the United States. 

Paracelsus, renowned physician and medical writer in the first half of the sixteenth century, called opium the philosopher s stone of immortality. In European medicine of the sixteenth and seventeenth centuries opium found wide use as an analgesic and sedative, although its abuse had become known from journeys of discovery to the Near and Far East. In the early nineteenth century a German pharmacist. Friedrich Sertumer. isolated the particularly active morphine from natural opium and this became widely used in military medicine as an analgesic and anesthetic in the latter half of that century. 

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