Case study (Applied Pharmacology) - Essay Example

?Q1. Explain the rationale for this with the presumption that the patient has no co-morbidities. Can you suggest likely changes to personal circumstances that may have led to the patient having a different response to the two other individuals? (10 marks). The effects of heroin vary among individuals. The most common cause of this variation includes: difference in drug tolerance, and difference in drug purity (Fernandez & Libby, 2011). In addition, poly-drug use also increases the probability of fatal over dosage. Heroin overdose usually occurs to new users or recovering addicts, who slipped into their old habit and injected a dose similar to their peers or similar to the amount of heroin they were taking at the prime of their active use (Fernandez & Libby, 2011). Overdosage usually occurs as a result of decreased tolerance that causes the effects to double in magnitude resulting in respiratory arrest instead of the usual decreased in respiratory depth. Additives used by drug distributors to increase their profit such as quinine, milk sugar, starch, powdered milk, talcum powder, and fentanyl have been proven to cause serious health problems (Fernandez & Libby, 2011). Talcum powder, for instance, does not dissolve in the blood instead; it causes blood to coagulate, predisposing the user to deep vein thrombosis (Fernandez & Libby, 2011). Fentanyl--a more potent opiate analgesic than morphine when mixed with heroin--can amplify the effects of the latter causing respiratory depression and arrest, sedation, unconsciousness, and coma (National Institute on Drug Abuse [NIDA], n.d.). Apart from the dangers of the cutting agents mixed with the drug, heroin sold in the market was found out to be as pure as 40% from its typical purity of 17% to 20% (Sober Living by the Sea [SLS], 2010). Users who are unaware of the increased concentration may take the same amount of their usual dose, which had less than 40% of pure heroin and can easily overdose (SLS, 2010). Poly-drug use is an increasing trend among addicts. They do this to potentiate the effects of another drug, to counteract the effects of another drug, to be on the latest trend, and to use it as a replacement for their drug of choice, which is usually in conjunction with other drugs (Department of Education, Employment and Workplace Relations [DEEWR], n.d.). However, the dangers increase exponentially when drugs are taken in combination with other drugs since the effects can be doubled and the drug’s half-life can be prolonged (Watkins, n.d.). Q2. From a pharmacological perspective, explain the likely impact of the patients’ alcoholism and level of intoxication on his/her condition? (10 marks). Heroin is a synthetic opioid that stimulates specific receptors--mu, kappa, delta, in the central nervous system as well as in the periphery. These results in the inhibition of synaptic transmission; thus, depressing most of the body’s functions including heart rate, respiratory rate, and bowel movement among others (Flora, et al., 2004). Alcohol, on the other hand, lessens the excitatory effect of the neurotransmitter, glutamate, causing unconsciousness, and respiratory depression or arrest at high levels (Genetic Science Learning Center [GSLC], n.d.). Heroin and alcohol, which are both depressants, can act synergistically, compete for metabolism, and can potentiate the effects of each other in the CNS (Schuckit, 2006; Maisto, et al., 2011). Its combined effects can slow body functions enough to stop the heart from beating, to cause blood pressure to drop to dangerous levels, and to cause breathing to slow down or come to a complete halt (Maisto, et al., 2011). Q3. What would be your primary course of action? Describe the expected outcome and the physiological rationale for your intervention (10 marks). During an emergency, stabilizing the patient takes precedence over administration of an antidote to counteract the effects of the abused drug (Bebarta, n.d.). The effects of heroin such as: respiratory depression, decreased heart rate, and decreased blood pressure should be addressed first. Ventilating the patient with a bag-valve-mask will support the patients respiration (Greenberg, 2005; Bebarta, n.d.); chest compressions or CPR maintain adequate circulation, and assist the patients’ heart in pumping blood to the different body systems; and starting an intravenous line counters the patients’ hypotension (Flora, et al., 2004). Expected outcomes would include decrease pallor and increase of respiratory rate from the initial assessment. Q4. Detail the pharmacological intervention you are able to perform as a paramedic and using pharmacological principles justify the dose rate and route of administration you would use. If your first attempt at reversal is unsuccessful, what would be your strategy and why? (10 marks). In this case, the patient should be given a trial dose of 0.1 mg to 0.2 mg of Naloxone via the intravenous line to counter the effects of heroin on the central nervous system (Mitchell & Medzon, 2005). Following administration, the patient is expected to have an increase heart rate, pupillary dilation, and rousing from a state of somnolence (Mitchell & Medzon, 2005). Naloxone acts as an opioid antagonist that competes for the binding sites of the opioid receptors in the central nervous system, thereby promoting spontaneous breathing (Dean, et al., 2009; Kaplow & Hardin, 2007). It is used as an adjunct to support oxygenation that works within 1 to 2 minutes of intravenous infusion with a half-life between 30 to 80 minutes (Dean, et al., 2009). However, the drug should be given in small doses as this might precipitate opioid withdrawal from patients. Although withdrawal is not life-threatening, the unpleasantness of the symptoms can prevent the patient from considering stopping heroin usage (Bebarta, n.d.). If the patient does not respond to the initial dose, 2.0 mg of Naloxone can be given with administration of a 2.0 mg-repeat dose every 2 to minutes until a response can be noted or until 10 mg has been given (Kaplow & Hardin, 2007; Bebarta, n.d.). If no response can be noted after administering a total of 10 mg of Naloxone, it is best to re-evaluate the patient and consider poly-drug use (Bebarta, n.d.). In addition, respiratory rate should be closely monitored upon Naloxone administration (Flora, et al., 2004) and serum glucose levels, as well as thiamine levels should be assessed in patients with altered levels of consciousness, as low levels of oxygen, glucose and thiamine can lead to a coma (Bebarta, n.d.). Endotracheal intubation should be administered if there is inadequate response to naloxone and if inadequate ventilation and poor oxygenation persist (Greenberg, 2005). Q5. Do you consider it safe to leave this patient who is now breathing and conscious at home? Justify your answer with reference to the likely pharmacological impact associated with polydrug use in this patient. (10 marks). Amphetamines and heroin counteract each other’s immediate effects; which can lead to overdose on one, or both (Heroin Detox Rehab, n.d.). Amphetamine is a stimulant that acts by inhibiting reuptake as well as inhibiting monoamine oxidase from degrading biogenic amines (Handly, 2009). Elevated levels result in an increased state of arousal, decreased fatigue, hyperthermia, tachycardia, hypertension, and vasospasm among others (Handly, 2009). Although the patients’ condition has improved after administration of Naloxone, the effects of the other drugs used in conjunction with heroin, in this case alcohol and amphetamine may appear and cause detrimental effects with heroin subsiding from the system. Apart from the dangers of polydrug use, overdose on long-acting opioids may require continuous infusion of 0.4 mg/hr, or two thirds the initial dose of Naloxone to ensure that the patient does not stop breathing again (Kaplow & Hardin, 2007). Also, non-cardiogenic pulmonary edema almost always happens with heroin overdose and it usually begins immediately, or may be delayed for up to 2 hours (Mitchell & Medzon. 2005). It is therefore imperative for the patient to be placed under observation for 6 hours in the emergency department (Mitchell & Medzon, 2005). Q6. What would you do differently and why? (10 marks). Codeine is a prototypic opiate derived from the sap of Papaver somniferum that is used as an analgesic. Methadone, on the other hand, is a synthetic opioid that is also used as an analgesic and to treat opiate addiction (Hauser, 2006). Treatment for codeine overdose in children less than 5 years old involves the administration of Naloxone via intravenous and subcutaneous, intramuscular, or via endotracheal tube if an intravenous line is not available with a computed dose of 0.1 mg per kilogram body weight (Fleisher & Ludwig, 2002). However, for methadone overdose, naltrexone should be used in lieu of naloxone since methadone is a longer acting drug than heroin or codeine, and needs a longer-acting opioid antagonist to counter its effects (Hauser, 2006). References Bebarta, V., n.d. Opioids. In: V. Markovchick & P. Pons, eds. 2003. Emergency medicine secrets: Questions and answers reveal the secrets to safe and effective emergency medicine. 3rd ed. Philadelphia, USA: Hanley & Belfus, Inc. Ch.87. Dean, R. Bilsky, E. & Negus, S. eds., 2009. Opiate receptors and antagonists: from bench to clinic. USA: Humana Press. Department of Education, Employment and Workplace Relations, n.d. Poly-drug use [Online]. Available at: http://www.deewr.gov.au/Schooling/Programs/REDI/ecstasydrugs/infodrugs/consequencesuse/Pages/use.aspx [Accessed 23 May 2011]. Fernandez, H. & Libby, T., 2011. Heroin: its history, pharmacology, and treatment. 2nd ed. Minnesota: Library of Congress. Fleisher, G. & Ludwig, S. eds., 2002. Synopsis of pediatric emergency medicine. 4th ed. Philadelphia, USA: Lippincott Williams & Wilkins. Flora, S. Romano, J. Baskin, S. & Sekhar, K. eds., 2004. Pharmacological perspectives of toxic chemicals and their antidote. USA: Narosa Publishing. Genetic Science Learning Center, n.d. How drugs can kill. [Online] Available at: http://learn.genetics.utah.edu/content/addiction/drugs/overdose.html [Accessed 23 May 2011]. Greenberg, M. ed., 2005. Greenberg’s text-atlas of emergency medicine. Philadelphia, USA: Lippincott Williams & Wilkins. Handly, N., 2009. Amphetamine toxicity. [Online] Available at: http://emedicine.medscape.com/article/812518-overview#a0104 [Accessed 24 May 2011]. Heroin Detox Rehab, n.d. Dangers of mixing heroin with alcohol and other drugs. [Online] Available at: http://www.heroindetoxrehab.com/heroin/dangers-of-mixing-heroin-with-alcohol-and-other-drugs/ [Accessed 23 May 2011]. Hauser, S. ed., 2006. Harrison’s neurology in clinical medicine. USA: McGraw-Hill. Kaplow, R. & Hardin, S., 2007. Critical care nursing: synergy for optimal outcomes. Massachusetts: Jones & Bartlett Learning. Maisto, S. Galizio, M. & Connors, G., 2011. Drug use and abuse. 6th ed. USA: Wadsworth Cengage Learning. Mitchell, E. & Medzon, R., 2005. Introduction to emergency medicine. Philadelphia: Lippincott Williams & Wilkins. National Institute on Drug Abuse, n.d. Fentanyl. [Online] Available at: http://www.nida.nih.gov/drugpages/fentanyl.html [Accessed 23 May 2011]. Schuckit, M., 2006. Drug and alcohol abuse. 6th ed. USA: Springer Science+Business Media, Inc. Sober Living by the Sea, 2010. Heroin purity and supply increase combined with drop in price create a deadly phenomenon. [Online] (Updated 21 Jan 2010) Available at: http://www.soberliving.com/blog/heroin-purity-and-supply-increase-combined-with-drop-in-price-create-a-deadly-phenomenon [Accessed 23 May 2011]. Watkins, A., n.d. Opiate painkillers and poly-drug abuse among young people. [Online] Available at: http://www.buprenorphine-detox.net/buprenorphine_detox/opiate-painkillers-and-poly-drug-abuse-among-young-people.php [Accessed 23 May 2011]. Read More