Vomiting morphine

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). 

There are two main treatments for the opiate withdrawal syndrome. One is replacement therapy with methadone or other X agonists that have a longer half-life than heroin or morphine, and produce mild stimulation rather than euphoria. They also produce cross-tolerance to heroin, lessening heroin s effect if patients relapse. Withdrawal is also treated with the 0C2 agonist clonidine, which inhibits LC neurons, thus counteracting autonomic effects of opiate withdrawal — such as nausea, vomiting, cramps, sweating, tachycardia and hypertension — that are due in part to loss of opiate inhibition of LC neurons. 

Morphine is considered by many clinicians to be the first-line agent for moderate to severe pain. Nausea and vomiting are more likely in ambulatory patients and with the initial dose. 

Morphine also causes nausea and vomiting by stimulation of the area postrema. Nausea is a common reaction to intravenous injection, but tolerance develops to this effect over repeated use. 

Apomorphine hydrochloride (44 Apokyn Bertek, 2004), is a semisynthetic derivative of opium alkaloid morphine (43) isolated from poppy (Papaver somniferum), and it has long been known for its erectile activity at the effective dose of 2-6 mg physicians discovered the effect over 100 years ago, but found the drug, at a much higher dose (ca. 200 mg), to be more suitable for poison victims as an emetic because it also causes serious nausea and vomiting. Apomorphine exerts its erectile effect at the central nervous system the drug has been found to be a non-selective dopamine agonist which activates both Di-like and D2-like... 

Mediates its effects by activating the microopioid receptor it shows equivalent analgesia to morphine but to have a superior side-effect profile in terms of reduced liability to induce nausea and vomiting and respiratory depression. 

Oxymorphone is approximately 10 times more active than morphine. Euphoric effects as well as vomiting are expressed significantly stronger than in morphine. Oxymorphone also displays poor antitussive activity. 

Nalorphine has less of an analgesic effect than morphine however, it does not have much value as an independent analgesic. It is used as an antagonist to narcotic analgesics. It eliminates suppression of the respiratory center, bradycardia, and vomiting caused by opiate receptor agonists. 

The most common side effect of pentazocine is sedation resulting from an interaction with the K-receptor. Also observed are sweating, dizziness, psychotomimetic effects, anxiety, nightmares, and headache. Nausea and vomiting are less frequent than with morphine. Respiratory depression and increased heart rate, body temperature, and blood pressure accompany overdose. Naloxone is effective in reducing the respiratory depression but requires the use of higher doses than for morphine overdose. 

B. Two medicines, ipecac and apomorphine, induce vomiting. Metoclopramide is a prokinetic with antiemetic properties and therefore would have the opposite of the desired effect. Morphine is an opioid with analgesic and sedating properties. Promethazine and ondansetron are also antiemetics, not emetics. 

The answers are 264-c, 263-c. (Katzung, pp 519, 535-537.) Heroin and other opioids (such as morphine and meperidine) exhibit a high degree of tolerance and physical dependence. The tolerance rate magnitudes to all of the effects of opioids are not necessarily the same. The physical dependence is quite clear from the character and severity of withdrawal symptoms, which include vomiting spasms, abdominal cramps, diarrhea, and acid-base imbalances among others. 

It is a reduction/decrease in the activity of specialized cells. For example barbiturates depress central nervous system, quinidine depresses myocardium. Certain drugs stimulate one type of cells but depress others e.g. morphine stimulates the vagus and chemoreceptor trigger zone but depresses the vomiting and cough centres. Similarly acetylcholine stimulates intestinal smooth muscle but depresses SA node in the heart. 

Morphine stimulates CTZ and produces nausea and vomiting. These effects are more marked in upright position due to vestibular involvement. 

CNS side effects include confusion, anxiety, lethargy, nausea and vomiting. GIT related effect is constipation. Other side effects are urinary retention, dry mouth, miosis, dysphoria, hypotension, skin rash, itching and urticaria. Tolerance, drug dependence and drug abuse are the main drawbacks of morphine. 

Head injury, because morphine can cause increase in intracranial tension, cause marked respiratory depression and certain physiological signs e.g. miosis and vomiting can interfere with the assessment of clinical progress. 

Side-effects Morphine induces a variety of centrally- and peripherally-mediated side-effects. The most important of which is respiratory depression following parenteral administration, especially in the postoperative situation. Chronic oral application induces constipation and chronic treatment with oral morphine must be supplemented with laxatives. Other frequent side-effects are nausea, vomiting, dizziness and sedation. 

Emetics are used to induce vomiting and are frequently administered to help empty the stomach of poisons or ingested toxins. The two primary emetics are apo-morphine and ipecac. Both agents seem to work by stimulating the medullary emetic center, and ipecac also exerts a direct emetic effect on the stomach. 

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