Opiate analgesics

In addition, morphine has served as a point of departure for the discovery of many medically usefnl derivatives. These inclnde codeine, a pain reliever and cough suppressant, levophanol, an orally active analgesic (morphine is not active when given orally and is nsnally given by injection), and many other modem and highly potent opiate analgesics. 

Medically Appropriate Use. This is not an issue in the assessment of alcohol or illicit drugs, but can be a consideration when there is suspicion of opiate analgesic or benzodiazepine abuse. Abuse of or dependence on these medications can lead to what is often derogatorily described as drug seeking behavior. The impli-... 

Opiate analgesics like codeine or dextropro-poxyphene are generally given in combination with the drugs listed above. No specific smdy is available demonstrating their efficacy for acute episodes despite the beneficial effect observed in certain patients. 

Long-term use of stimulant laxatives bisacodyl (Dulcolax), cascara sagrada, and Neoloid except in the presence of opiate analgesic use May exacerbate bowel dysfunction. High... 

Use with alcohol, CNS depressants, antihistamines, opiate analgesics, and other BZDs increases CNS depression. Quazepam is a pregnancy-risk category X drug, and breast-feeding whiie taking it is not recommended. 

Other types of drugs using this delivery system are clonidine and timolol (antihypertensives).estradiol (postmenopausal prophylaxis), fentanyl (opiate analgesic), and nicotine ("the patch"). 

HA, mild pain Action Nonnarco tic analgesic w/ barbiturate Dose 1—2 tabs or caps PO q4-6h PRN i in renal/hepatic impair 4 g/24 h APAP max Caution [C, D, +] Alcoholic liver Dz Contra G6PD deficiency Disp Caps, Liq, tabs SE Drowsiness, dizziness, hangover effect Interactions T Effects OF benzodiazepines, opiate analgesics, sedatives/hypnotics, EtOH, methylphenidate hydrochloride i effects OF MAOIs, TCAs, corticosteroids, theophylline, OCPs, BBs, doxycycline EMS See Acetaminophen may impair coordination, monitor for depression concurrent EtOH use T CNS depression butalbital is habit forming... 

Markley, H.G., Chronic headache appropriate use of opiate analgesics, Neurology, 44, SI8, 1994. 

The term "opioid" is used to designate a group of drugs that have opium-like or morphine-like properties. The term "opiate analgesic" is often used as an alternative. The term "narcotic analgesic" is now obsolete it was formerly used to describe potent opiate analgesics which had sedative properties. 

Figure 15.2. Structures of opiate analgesics and their antagonists (last five listed).

All agonists in this therapeutic group decrease the sensation of painful stimuli, which is their main clinical application. They tend to subdue dull, persistent pain rather than sharp pain, but this difference is to some extent dose dependent. The major difference between the non-opioid analgesics such as aspirin and the opiates is that the former reduce the perception of peripherally mediated pain, by reducing the synthesis of local hormones that activate the pain fibres, whereas the latter attenuate the affective reaction to pain without affecting the perception of pain. This clearly suggests that the site of action of the opiate analgesics is in the central nervous system. 

One of the serious complications of the use of the opiate analgesics, even at therapeutic doses, is respiratory depression, an effect which is further complicated by the ability of these drugs to decrease the sensitivity of the respiratory centre to carbon dioxide. The administration of oxygen to a patient whose respiration has been depressed by the opiates is therefore counterproductive and may lead to total respiratory paralysis. 

Many opiate analgesics are effective cough suppressants (also called anti-tussives), although only codeine and dihydrocodeine are generally used for this purpose. As there is a dissociation between the anti-tussive and analgesic action of the opiates, dextromethorphan and noscapine are now commonly used as cough suppressants because of their efficacy and lack of dependence-producing properties. 

Inturrisi CE. Opiate analgesic therapy in cancer pain. In Forley KM, ed. Advances in Pain Research and Therapy. Vol. 16. New York Raven Press, 1990 133-154. 

Tropane derivatives were found not only to decrease the effect of opiate analgesics but also to prevent the development of the analgesic action of opiates.68... 

O-R agonist [Naloxone-reversed opiate analgesic effects] [analgesic, (piperidine) antinociceptive]... 

Anesthetics Antihistamines Antiparkinsonian agents Barbiturates Benzodiazepines Chloral hydrate Hypoglycemic agents Opiate analgesics Thyroid extract Tricyclic antidepressants... 

Some studies have suggested that there may be links between the development of dependence to cannabinoids and to opiates (42). Some of the behavioral signs of rimonabant-induced withdrawal in THC-treated rats can be mimicked by the opiate antagonist naloxone (43). Conversely, the withdrawal syndrome precipitated by naloxone in morphine-dependent mice can be partly relieved by THC (44) or endocannabinoids (45). Rats treated chronically with the cannabinoid WIN55212-2 became sensitized to the behavioral effects of heroin (46). Such interactions can also be demonstrated acutely. Synergy between cannabinoids and opiate analgesics has been described above. THC also facilitated the antinociceptive effects of RB 101, an inhibitor of enkephalin inactivation, and acute administration of THC caused... 

Morphine, the natural alkaloid from which almost all opiate analgesics have been evolved, is stereospecific in the receptor interactions that are responsible for its opioid actions, namely, analgesia, depression of respiration, dependence liability, and GIT disturbances. Compounds with natural (-) and unnatural (+) geometry may exhibit antitussive actions. 

Animal (frog) (snake) Epibatidine Pain (non-opiate analgesic)... 

In common with other phenolic opiate analgesics, buprenorphine shows low peroral potency, suggesting a high first-pass metabolism effect indeed, work in rats has shown this to be the case. Intravenous studies have estimated that the extraction ratio of buprenorphine is 85% and that peroral systemic availability is consequently expected to be 15% or less. Although absorption from the mouth is slow and, therefore, not as useful as parenteral administration in the treatment of acute pain, it offers a major bioavailability advantage over the peroral route for this drug. If required, the patient can be given a parenteral dose of buprenorphine to achieve rapid pain relief and... 

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