Pharmacology of opioids. Questions on Drugs - Essay Example

?Question Present the pharmacology of opioids, including chemical changes and mechanism of action. Opioid receptors are coupled with protein-nas G (G ?i / ?o). Upon stimulation of a receptor opioid inhibition adenylate cyclase activity occurs with reduced cAMP concentration and activity of cAMP dependent protein kinase or PKA, resulting in a decrease phosphorylation of proteins. It also produces a facilitation of closure calcium channels in neurons presinapti-CAS thereby reducing the release of neuro-transmittor and the opening of channels potassium (GIRK) of postsynaptic neurons policies. This causes hyperpolarization of the membrane and results in a reduction of activation. Therefore, they are receptors that mediate inhibitory actions. Discuss why, if there are no chronic toxicities directly related to the use of opioids, opioid dependence would be a problem for users in the long term. Repeated administration of opioids may become a habit. The side effects include a lack of control over the substance, compulsive use and the presence of problems medical and social. Abrupt withdrawal triggers opioid-abs syndrome incontinence (physical dependence). The abstinence is flu-like, with yawning, mydriasis, rhinorrhea, muscle pain, sweating, piloerection, nausea and vomiting, diarrhea, fever, insomnia. It causes anxiety. It also presents a desire very intense for the drug (depending on psychic dependence or craving). Discuss the changes in the populations of opioid users. Include in this discussion the debate around the availability of Naloxone. It is estimated that opioid overdose kills around 15,000 Americans every year (Szalavitz). Naloxone is a competitive antagonist of opioid receptors. It blocks predominantly mu receptors and, to a lesser extent, affects the other opioid receptors and eliminates the effect of both endogenous opioid peptides and exogenous opioids. Naloxone prevents, reduces or eliminates (depending on the dose and time of administration), the effects of opioid analgesics, restores breathing, reduces sedation and euphoria and reduces the hypotensive effect. A continuous debate is in progress regarding whether naloxone would lead to a “false sense of security” which may result in a corresponding rise in the usage of heroin. However, from the limited evidence the reverse seems to be true. Question 2 Describe several of the psychoactive plants presented in Chapter 14 of your textbook, identifying the active chemicals contained within them, the class of hallucinogens to which they belong, and their purported psychological effects. Cannabis sativa- Scientists have identified more than 61 chemical ingredients, known as "cannabinoids", specific to cannabis. THC (delta-9-tetrahydrocannabinol) is the primary psychoactive cannabinoid (Fusar-Poli, Crippa and Bhattacharyya). It belongs to the hallucinogenic class of cannabinoids. Cannabis can cause psychological dependence. Effects include: Relaxation, Disinhibition, Hilarity, Feeling slow over time, Sleepiness, Sensory disturbances, Difficulty in carrying out complex functions: communicate clearly, immediate memory, concentration, learning processes. Atropa Belladonna - The active constituents in Atropa belladonna are atropine, hyoscyamine and scopolamine. It belongs to the hallucinogenic class of piperidines. It can cause psychological effects like hallucinations, delirium and mind dissociation. Lophophora williamsii – Chemicals contained in this plant include Alkaloids, Lophophorine, Lophotine, Mescaline and Pellotine. It belongs to the hallucinogenic class of indole alkaloids. The sychological effects are that it is sympathomimetic, profoundly alter perception of self and reality, increase suggestibility, and intensify emotions. Should research efforts be encouraged to determine the possible use of these hallucinogens in efforts to improve the human condition? Explain your viewpoint, addressing either your objections or advocacy, supported by tenable assumptions and sound reasoning. Dr. Max Rinkel, Center for Mental Health of Massachusetts, introduced the LSD in the U.S. in 1949. The first experiments were aimed at improving the conditions of schizophrenics. The aim was to bring in healthy people, who willingly lend to, a transient psychotic state similar to schizophrenia, to learn more about it. The LSD was then considered psychomimetic, i.e. capable of producing a temporary psychosis. Since the researchers considered the similarities between schizophrenia and the effects of LSD were actually superficial, was abandoned this line of research. However, in 2007 a ??new research conducted at the Mount Sinai School of Medicine in New York showed that the analogy itself is unfounded: LSD affects the same receptors of serotonin and glutamate functioning abnormally in schizophrenics. So if you find drugs that block the effects of LSD on these receptors, is also likely to be effective in combating the symptoms of schizophrenia. Develop at least three strong reasons to avoid experimentation with LSD, based on the experiences of others who have reported adverse reactions and other problems. In 1938 the Swiss chemist Albert Hofmann successfully synthesized LSD. Initially it was believed that LSD could be a new promising and revolutionary medicine drug. However, after many test trials it was concluded that LSD in medicine cannot be used effectively. Aldous Huxley was one of the first who tried LSD for non-medical reasons. The uncanny effect of LSD-25 was discovered in 1943, but only in recent months have far-reaching series of experiments have been brought to an end. The drug is a semisynthetic ergot preparation and works in surprisingly small doses - 30 to 100 millionths of a gram. In the United States in the early sixties Dr. Timothy Leary at Harvard University experimented with LSD on his students. He initially developed promising experiments with LSD parties. Leary was then discharged and he formed his own organization, the IFIF (International Federation for Internal Freedom). Leary later became one of the most important people in the hippie movement. Ken Kesey, who was a student of Leary, also took part in the LSD experiments and was a staunch devotee of LSD. In 1966 LSD was banned in the United States and set by the influence of the U.S. on the list of the most dangerous drugs. Later, LSD was banned in Europe. How would you describe the particular challenges facing law-enforcement personnel when confronted by a possibly dangerous perpetrator suspected of being under the influence of a powerful psychoactive drug, such as PCP/"angel dust"? In such a situation the law enforcement personnel has to be very careful that the perpetrator does not hurt him. Under the influence of angel dust it is expected that the perpetrator would be rampaging, destroying property and even attempting to hurt people. The law-enforcement official could use a taser to back off the offender. He could use the police dog for his safety. However, if the offender is very close to actually killing him off I believe it would be justified if the personnel shot him. Should a drug-induced, alleged perpetrator be held accountable – legally? Explain your viewpoint. A drug-induced, alleged perpetrator is equally responsible for any crime he commits. It is common knowledge that drugs can make one do things that one normally would not. However, when a person is taking a drug he should be absolutely aware of the consequences and what it may lead to. Legally, committing crimes under voluntary intoxication cannot be excused. However, there are certain states that allow some defensive but still the perpetrator is charged, even if less. Works Cited Fusar-Poli, P, et al. "Distinct effects of (delta)9-tetrahydrocannabinol and cannabidiol on neural activation during emotional processing." Arch Gen Psychiatry 66.1 (2009): 95-105. Szalavitz, Maia. Naloxone Debate: FDA Hears Testimony About Making an Overdose Antidote Nonprescription. 13 April 2012. 26 October 2012 . Read More