Opiates naloxone

If the individual has not taken or received an opiate, naloxone has no drug activity. 

Opiates Naloxone 0.4-2 mg IV every 3 min Support vital functions... 

Reversal of reqriralory dqiresaon due lo opiates Naloxone QJ04 mg/1(g in dogs IV. IM. or SC. 

Opiates iateract with three principal classes of opioid GPCRs )J.-selective for the endorphiQS,5-selective for enkephalins, and K-selective for dynorphias (51). AU. three receptors have been cloned. Each inhibits adenylate cyclase, can activate potassium channels, and inhibit A/-type calcium channels. The classical opiates, morphine and its antagonists naloxone (144) and naltrexone (145), have moderate selectivity for the. -receptor. Pharmacological evidence suggests that there are two subtypes of the. -receptor and three subtypes each of the 5- and K-receptor. An s-opiate receptor may also exist. 

Zipeprol [34758-83-3] (58) is another European antitussive with a wide range of pharmacological effects, including antispasmodic, antihistaminic, and local anesthetic activities (85,86). It has been reported that zipeprol has been abused in Italy because high doses cause hallucinations (87). Spontaneous withdrawal symptoms similar to those of opiates have been observed withdrawal symptoms can also be precipitated by naloxone. Zipeprol can be... 

Opiate overdose is a medical emergency that can result in respiratory and CNS depression. The opioid receptor antagonist naloxone immediately reverses cardiorespiratory depression. However, repeated naloxone administration is required, since the effects of naloxone last for 30 min, while opioid agonists can remain at potentially lethal blood levels for several hours. 

The pharmacological and/or adverse effects of a drug can be reversed by co-administration of drugs which compete for the same receptor. For example, an opioid receptor antagonist naloxone is used to reverse the effects of opiates. Drugs acting at the same site with opposite effects also can affect each other, e.g. the reduction in the anticoagulant effect of warfarin by vitamin K. 

Administration of naloxone prevents or reverses the effects of the opiates. The exact mechanism of action is not fully understood, but it is believed that naloxone reverses opioid effects by competing for opiate receptor sites (see Chap. 19). If the individual has taken or received an opiate, the effects of the opiate are reversed. 

These dm may produce withdrawal symptoms in those physically dependent on the narcotics. The patient must not have taken any opiate for the last 7 to 10 days. Naloxone may prevent die action of opioid antidiarrheals, antitussives, and analgesics. This drug is used cautiously during lactation. 

Naltrexone completely blocks the effects of IV opiates, as well as drugp with agonist-antagonist actions (butorphanol, nalbuphine, and pentazocine). The mechanism of action appears to be the same as that for naloxone... 

The initial dose of buprenorphine should be given at least 12-24 hours after the last heroin dose, 24 hours after the last methadone dose, or 48 hours after the last LAAM dose (see Table 2-3). The methadone dosage of methadone maintenance patients should be reduced to 30 mg/day before the transfer to buprenorphine is attempted. Ideally patients should show clear evidence of opiate withdrawal before receiving the first dose of buprenorphine, to avoid the risk that buprenorphine will precipitate more severe withdrawal. For the first day, sublingual buprenorphine/naloxone doses of 2/0.5-4/1 mg can be given every 2-4 hours, up to a maximum total dose of 8/2 mg/day. On the... 

Rabinowitz J, Cohen H, Kotler M Outcomes of ultrarapid opiate detoxification combined with naltrexone maintenance and counseling. Psychiatr Serv 49 831—833, 1998 Reed PA, Schnoll SH Abuse of pentazocine-naloxone combination. JAMA 256 2562— 2564, 1986... 

There are now selective antagonists for all three opiate receptors (see Table 21.2) but with the exception of naloxone they are experimental tools for probing the functional roles of the opiate receptors. Naloxone is a potent competitive antagonist at all three receptors with highest affinity for the mu receptor. It will rapidly reverse all opiate... 

We examined the effects of three such stereoisomer pairs of "sigma opiates" on 86Rb efflux in synaptosomes in the presence of 10 pM naloxone (to avoid classical opiate effects). Our data show (Bartschat et al. 1985) that dexoxadrol blocks Sv at one-thousandth the concentration of its stereoisomer, levoxadrol ... 

In order to effectively treat respiratory acidosis, the causative process must be identified and treated. If a cause is identified, specific therapy should be started. This may include naloxone for opiate-induced hypoventilation or bronchodilator therapy for acute bronchospasm. Because respiratory acidosis represents ventilatory failure, an increase in... 

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... 

H26. Holiday, J. W and Faden, A. I Naloxone acts at central opiate receptors to reverse hypotension, hypothermia, and hypoventilation in spinal shock. Brain Res. 19,295-299 (1980). 

Wang, G.J., Volkow, N.D., Fowler, J.S. et al. Dopamine D2 receptor availability in opiate-dependent subjects before and after naloxone-precipitated withdrawal. Neuropsychopharmacology. 16 174, 1997. 

The pharmacological properties of the cloned opiate receptors are similar to the characteristics of the endogenously expressed receptors [9, 36, 45]. The binding of opiates to the cloned receptors is stereoselective and the antagonist naloxone interacts with all three of the cloned receptors, although naloxone had much lower af-... 

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