Hyperactivity morphine

Adverse effects Large doses of meperidine cause tremors, muscle twitches, and rarely, convulsions. The drug differs from opioids in that in large doses it dilates the pupil and causes hyperactive reflexes. Severe hypotension can occur when the drug is administered postoperatively. When used with major neuroleptics, depression is greatly enhanced. Administration to patients taking monoamine oxidase inhibitors (see p. 123) can provoke severe reactions such as convulsions and hyperthermia. Meperidine can cause dependence, and can substitute for morphine or heroin in use by addicts. Cross-tolerance with the other opioids occurs. 

The pattern and overall incidence of untoward effects that follow the use of meperidine are similar to those observed after equianalgesic doses of morphine, except that constipation and urinary retention may be less common. Patients who experience nausea and vomiting with morphine may not do so with meperidine the converse also may be true. As with other opioids, tolerance develops to some of these effects. The contraindications generally are the same as for other opioids. In patients or addicts who are tolerant to the depressant effects of meperidine, large doses repeated at short intervals may produce an excitatory syndrome including hallucinations, tremors, muscle twitches, dilated pupils, hyperactive reflexes, and convulsions. These excitatory symptoms are due to the accumulation of normeperidine, which has a half-life of 15 to 20 hours compared with 3 hours for meperidine. Opioid antagonists... 

In subjects who are addicted to morphine, the initial symptoms of the abstinence or withdrawal syndrome usually appear 6 to 12 hours after the last dose and consist of CNS irritability and feelings of fatigue, autonomic hyperactivity such as tachycardia and hypertension, gastrointestinal hyperactivity such as diarrhea, and autonomic supersensitivity such as insomnia and restlessness. 

Alcohol, barbiturates, and narcotics—such as diphenhydramine (Benadryl), amobarbital (Amytal), diazepam (Valium), codeine, heroin, methadone, morphine, propoxyphene (Darvon)—that are used during pregnancy can lead to harmful effects on the newborn. Use of these dmgs during pregnancy can create an addiction in the newborn. The baby will go into withdrawal from the drug when they are born. This can result in hyperactivity, crying, irritability, seizures and even sudden death. 

Morphine-induced catalepsy has also been studied. The response to morphine may be of two types, since both reduction of activity with enhancement of cataleptic response and increase in hyperactivity and decrease in response to morphine challenge have been noted (Mitchell et al., 1982). These results are confusing but do not exclude the possibility of changes in opioid-induced behaviour. 

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