The time taken by opiates to enter the brain or the pace at which they travel to the brain is largely dependent on the route the user adopts to take them. In fact, the quickest manner to enter the brain or become 'high' is to take the injectionable form of opiates, as it helps the opiates to get into the bloodstream directly. Smoking is the second fastest way for the opiates to enter the brain. It may be noted that when people inject opiates into their bloodstream or smoke them, it takes only a few minutes to attain the peak level or a 'high'. Among all opiates, fentanyl is known to dissolve in fatty substances most easily and, hence, it also achieves the utmost concentrations in the brain within seconds. In fact, this is one reason why this opiate is so popular among the drug users, especially those who use it for non-medicinal purposes. Heroin, on the other hand, is a little sluggish in entering the brain - a couple of minutes are needed for it to enter the brain. Morphine is even slower in entering the brain and takes about five minutes to do so - not much slower when compared to heroin. It needs to be cautioned, the fastest an opiate gets into the brain and gives a 'high', more is the chance of death owing to overdo, as the levels of the drug in the brain is able to go up so rapidly. It is very natural that snorting or sniffing opiates takes a longer time for the body to take them up. In this case, the drug will have to pass through the mucous membranes within the nose and then to the blood vessels beneath them.
We have talked about injecting and snorting opiates, so what happens when we take opiate pills? In this case it takes a much longer time for the opiate to reach the brain and, therefore, the 'high' too also comes very slowly for the drug must first be taken up by the small intestine and then pass it on to the bloodstream, which will take the opiate to the liver for metabolizing most of the dosage before it can get back to circulation and enter the brain. Hence, it takes about 30 minutes for the drug from the time to popping the pill to reach the brain. Therefore, in this case no rush is created within.
The primary reason why methadone is very effective for the treatment of drug addicts and also in the form of an analgesic (pain killer) is that it does not create a rush. However, at times, regular drug users are able to find a way to get around the opiate formulations that are meant to have a gradual onset - OxyContin is an ideal as well as notorious example of this. In effect, OxyContin is an extended-release form of oxycodone, which is intended to release its contents slowly helping the sufferers to experience relief from pain over a prolonged period. However, when the users crush the pill and take it orally or inject a saline suspension of the drug, it gives a quick 'high' - something that was never intended by its manufacturers. Because of its abuse by drug users, OxyContin soon gained the repute of being a 'hot' drug. However, the fact remains that OxyContin is just a garden-form of opiate analgesic medication that can effectively ease pain provided it is used in the appropriate manner. When abused, this drug may lead to a series of undesirable effects. Hence, OxyContin is neither an exceptional drug, nor is it magical.
As far as the time for which the buzz after taking opiates lasts is concerned, there is little diversity. However, there are certainly some differences as to how fast the buzz starts. For instance, the buzz brought about by majority of the opiate drugs discussed in this article usually continues for anything between four and six hours. While the precise time may range from a minimum of two hours (in the case of morphine) to a maximum of about six hours (in the case of propoxyphene), but, generally speaking, all opiates are somewhat same. However, there are just two major exceptions to this. The effect of methadone continues for anything between 20 hours and 24 hours and, hence, a single daily dose of this opiate drug may be sufficient. On the other hand, fentanyl is another extreme - its effects generally fade away within just an hour. Precisely speaking, the period for which the action of the opiates lasts is largely conditional on the time consumed by the enzymes which metabolize the drugs in the liver to disintegrate any particular opiate drug.
The endeavour of the opium poppy to produce opium alkaloids may perhaps mirror the original plant evolution to contest the biology of their pillagers/ pollinators. In fact, the opium poppy plant has been able to work out the process to produce a compound that had an influence on their brains. Precisely speaking, it is not only the poppy plant which has been achieve to attain this feat, as there are several plants that also produce compounds, which are psychoactive. In other words, several plants are able to make compounds that have a significant effect on the mental process. For instance, several species of hallucinogenic mushrooms, the marijuana plant and the coca shrub are among such plants that also possess the aptitude to have an influence on the actions as well as functioning of animals that consume them. In addition, plants are not the only living things that can produce opioids, as specific types of frogs can also produce compounds that are similar to opioids. These frogs produce the opioids on their skin and most possibly they are also used for similar purposes.
All opiates work on particular receptor molecules for the enkephalin/endorphin category of neurotransmitters within the brain. Such endogenous opioids are basically chemical neurotransmitters, which regulate the movement, dispositions and functioning of the animals. They also assist in regulating several other physical activities, counting breathing, digestion and controlling the body temperature of the animals. In addition, these endogenous opioids facilitate in processing the feelings of pain, and they also turn on the reward circuits, and when they are excited, they make you experience a 'high'. All such actions occur when the neurons present in the different areas of the brain release enkephalins or endorphins. Generally, every single neuron does its own work, and starts shooting only when it is required. It may be noted that virtually there never occurs a situation when all the endogenous opioid neurons are activated at the same time. When you take heroin, it causes an effect which is something like all the endogenous opioid neurons within the brain firing simultaneously.
Now the question arises as to which of the several endogenous opioid neurons in the brain are precisely responsible for experiencing a 'high' after taking an opiate. The first among them is a small set of neurons present in the hypothalamus of the brain. In fact, this is the place where the neurons which make use of the primary endorphin neurotransmitter beta-endorphin first get activated and, subsequently, they extend or split up all over the brain. According to a hypothesis, all these neurons turn out to be dynamic when there is too much pressure and work to calm down the opiate user. The theorists hypothesize that when the body is enduring intense stress, for instance, when one is just about to die, a feeling of peaceful relaxation is all that is most needed at that particular moment. In such situations, beta-endorphin neurons shoot as if they are wild and bring on a pleasing condition something akin to those induced by opioids. It may be mentioned here that at present, scientists are almost half-way on their mission of substantiating that beta-endorphin has the aptitude to bring about such a condition. We are aware of the fact that taking beta-endorphin injections in the brain generates several phases of such a condition, which also includes decelerated breathing, drowsiness as well as analgesia.
Unlike the beta-endorphin, the case of enkephalins presents a different story. Various dissimilar types of neurons utilize enkephalins to be in touch with other neurons. The enkephalins are present in the areas of the brain that are engaged in processing sensations related to pain, regulating breathing as well as additional functioning that are affected by the opiates. In fact, the enkephalins are also present in the gastrointestinal tract and here their job is to regulate the digestive function. Most importantly, the enkephalins are also present in numerous places in our body that are concerned with the reward system and their presence in such places may possibly be vital. Nevertheless, they possibly do not work in cohesion or as an organized unit, something different from the endorphin neurons.
Therefore, it may be said that the enkephalins and endorphins are actually dissimilar members belonging to an intimately associated neurotransmitter 'family'. A third member of this so-called family is called the dynorphins and they too perform similar actions, including analgesia, but, in reality, result in disagreeable instead of an enjoyable feeling. All these three different neurotransmitters also share common receptors. Probably, this is one resourceful evolutionary ploy by the brain to obtain the maximum 'excitement for the money spent' from the neurotransmitters as well as their receptors. It is possible to generate numerous potential combinations that would eventually turn out a vast assortment of effects by merging the dissimilar opioid peptides with their receptors.
These neurotransmitters generate a variety of influences by means of sharing three dissimilar types of receptor molecules. The most important opiate receptor, which is called 'mu' - a Greek alphabet, offers the key effects of opiates, which include ecstasy, analgesia, slowed respiration and others - the effects produced by all opiates. The principal supporting receptor, called the 'delta' works together with 'mu' in some areas to facilitate in generating similar effects. The third receptor is called the 'kappa' and this has a bizarre nature. Drugs which are especially meant for this particular receptor generate sensations like analgesia, but they never give the user a 'high'. This might make you think that this is an ideal analgesic drug that does not lead to addiction. However, it has one downside too - invigorating this receptor itself results in a state that is just opposite of euphoria, or dysphoria (a condition of restiveness, dissatisfaction and nervousness). It is really unfortunate that every clinically helpful drug that we are currently using is only specific for the 'mu' receptor, and, hence, all these drugs are addictive too. The fact is that so far it is not possible to differentiate the addicting properties of the opiates from their analgesic attributes.