Opioid analgesics - Term Paper Example

Opiod analgesics can be natural, semi-synthetic, fully synthetic or endogenous in nature. The naturally occurring opiods can be attaned by incising a seed pod which has a substance known as opium. This opium contains alkaloids and the primary alkaloid is morphine. Semi synthetic opiods are the ones that are created from these natural opiates. Examples of semi-synthetic opiods are hydrocodone, desomorphine and buprenorphine. Fully synthetic ones are the ones created totally in the laboratory and these include fentanyl and pethidine.

Endogenous opiods are the ones that are produced inside the body and these include endorphins and enkephalins. Some names of opioids are Morphine, hydromorphone, oxymorphone, methadone, meperidine, fentanyl, sufentanil, alfentanil, levorphanol and codeine. Opioids are the most effective and best option of treatment of pain that has a chronic pattern and has been persisting for a very long time. It has been proved to be useful for unbearable and severe pain for relief. It is very useful in life hampering conditions which do not have a definite cure which include late stages of cancers and opioids are used in these pathologies.

It is also an option of treatment for anxiety. Other clinical uses include the usage of these drugs in spinal analgesia. Opiods can also be used as drugs for the treatment of diarrhea. They can also induce sleep and hence can be used as sedatives. Another common indication for opioids is in decreasing the reflex of cough. Opiods can also serve as emetic agents and can be used to induce vomiting. Acute pulmonary edema is a clinical condition which can be relieved by the provision of opiods by the mechanism of dilation of the vessels.

Certain opiods which have long lasting effects are used in the rehabilitation programs for the treatment of the opiod addicts so as to counter the withdrawal symptoms seen in these patients. The opioids are a class of drugs that have a good rate of absorption when they are taken by mouth. A few opioids serve as exceptions which include morphine, hydromorphone and oxymorphone. These drugs undergo the first pass effect before they enter the circulation. These drugs can hence be given by the parenteral route.

These drugs have the capability of reaching the most of the tissues of the human body. They can also cross the placenta. These drugs are acted upon by the enzymes of the liver and are converted into forms of glucoronide. Their route of removal from the human body is via the renal system. Alcohol has the ability of increasing the effects of the opioids on the human body. Also in patients with pathologies of the liver, the effect of the opiods becomes prolonged owing to the inactivity of the enzymes of the liver.

Opioids have the capability of working via three mechanisms that is via receptors, opioid peptides and via certain ionic pathways. The receptors of opioids are present in the peripheral nerves, in the cells of the gut as well as other important regions of the body. The receptors are classified as mu receptors, kappa receptors and delta receptors. The properties of the opioids responsible for relieving the pain are carried out via the mu receptors. The delta receptors are presented in the distal regions of the body and they are considered to be responsible for inducing tolerance to the drugs.

The kappa receptors are considered to be responsible for inducing sleep. These receptors of the opioids act via the second messenger, G proteins. They function via preventing the activity of