Effects of Pharmacology on Health - Assignment Example

PHARMACOLOGY Name: Institution: PHARMACOLOGY Pharmacokinetics 1. A patient has a malignant brain tumour. What pharmacokinetic phase may be affected by the presence of the tumour? a) Absorption b) Distribution c) Metabolism d) Excretion Explain?(4 marks) b) Distribution: The malignant brain tumour may affect the distribution pharmacokinetic phase because tumors result into drug delivery dysfunction in the tumor. The tumor achieves this through various mechanisms including failure by tumor cells to contact drugs directly leading to non-balanced distribution, increased pressure in the tumor with negative effects on permeation and drug distribution of drugs in the tumor, and structural abnormally of the tumor vessels, which affect drug distribution (Ciccone, 2007)). 2. A patient with cirrhosis of the liver exhibits decreased metabolic activity. This will require what possible changes? (Select all that apply) a) A reduction in the dosage of the drugs b) A change in the timing of medications administration c) An increase dose of prescribed drugs d) Giving all prescribed drugs by intramuscular injection e) More frequent monitoring for adverse drug effects Explain?(4 marks) In patients with liver cirrhosis, it is important to ensure reduction in the dosage of the drugs, change in the timing of medications administration, all prescribed drugs by intramuscular injection, and More frequent monitoring for adverse drug effects. This is because reduction of dosage of the drugs reduces drug accumulations and toxicity due to the reduced metabolism activity (Bullock & Manias, 2011). Change in the timing of medication administration is also important in achieving the same effect. Administration of drugs by instramuscular injection reduces the drug load that passes directly through the liver thus reducing toxicity and lastly frequent monitoring is necessary to ensure identification of advanced drug effects and toxicity in the body. An increase in the prescribed drug would be inappropriate because this would result into accumulation of the drug in the body and increased toxicity. 3. A patient who has renal failure may have a diminished capacity to excrete medications. The patient must be assessed more frequently for what development? a) Increased risk of allergy b) Decreased therapeutic drug effects c) Increased risk for drug toxicity d) Increased absorption of the drug from the intestines Explain?(4 marks) The patient must be assessed more frequently to observe or detect possible increased risk for drug toxicity. This is because the diminished capacity to excrete medications could result into accumulation of drugs in the body tissues with increased drug toxicity risk (Bullock & Manias, 2011). Upon such a development the physician in charge should be able to implement measures such reduction of the dosage or administration of less toxic alternative medications as well as treatments to enhance the excretion. Pharmacodynamics 4. What is the term used to describe the magnitude of maximal response that can be produced from a particular drug? a) Efficacy b) Toxicity c) Potency d) Comparability Explain?(4 marks) Efficacy is the term used to describe the magnitude of maximal response that can be produced from a particular drug. Maximal efficacy of a drug is based on the assumption that all receptors are occupied by drug and any increase of the drug would not translate to any change in the response (Bullock & Manias, 2011). Potency on the other hand refers to the amount of drug need to elicit a certain magnitude of effect. Compatibility refers to the interaction of two or more drugs to produce a desired physical or chemical change. 5. The doctor looks up butorphanol (Stadol) in the MIMS prior to administering the drug and notes that it is a partial agonist. What does this term tell the doctor about the drug? a) It is a drug that produces the same type of response as the endogenous substance. b) It is a drug that will occupy a receptor and prevent the endogenous chemical from acting. c) It is a drug that causes unpredictable and unexplained drug reactions. d) It is a drug that produces a weaker or less efficacious response than an agonist drug. Explain?(4 marks) A partial agonist is a drug whose efficacy is less than that of a full agonist but above zero. A partial agonist may have antagonistic effect against a full agonist especially when it has a higher affinity than the full agonist does. In this case, the doctor should know that butorphanol (Stadol) would not necessary achieve the desired unless the concentration of the partial agonist is increased until it achieves its maximal response or efficacy. As such, the doctor should opt for a full agonist instead of administering the partial agonist, which may become antagonistic in the event he or she tries to administer a full agonist drug. 6. If 10mg of morphine is considered to provide the same pain relief as 200mg of codeine. This indicates that the morphine would be considered more potent than codeine. (Fill in the blank) Why? This is because the amount of morphine required to achieve the same magnitude of effect (pain relief) is 20 times less than the amount codeine need to achieve a similar magnitude of effect. (1 mark) Autonomic nervous system 7. Anticholinergics may be given for which of the following conditions? (Select all that apply) a) Peptic Ulcer disease b) Bradycardia c) Decreased sexual function d) Irritable bowel syndrome e) Urine retention Explain?(3 marks) Anticholinergics may be used for treatment of Urine retention, irritable bowel syndrome, Bradycardia, and peptic ulcer disease. This is because the drug produce effect by blocking the postsynaptic cholinergic muscarinic receptor. The drugs induce increased gastric and renal secretion as well as increase gastrointestinal motility. Several synthetic anticholinergic drugs are used to alleviate urinary frequency and incontinence caused by hypertonicity of the urinary bladder (Ciccone, 2007). The rationale for use in peptic ulcer disease treatment is its ability to limit secretion of gastric acid. Anticholinergic drugs such as Atropine are applied in the treatment of symptomatic bradycardia because it reverses the effects of excessive vagal discharge. 8. A 74 year old female patient required catheter for 4 days postoperatively, and after removal, was still unable to void. She was recatheterised and a bladder rehabilitation program was begun that included bethanechol (Urecholine). What diagnosis should be considered as part of this patient’s plan of care given this new drug regimen? (5 marks) With the introduction of the new drug regimen (bethanechol) used to treat urinary retention, there is need to diagnose the patient for diarrhea which could likely due to the drug use. The mechanism of action of this drug would result into significant abdominal discomfort accompanied by diarrhea. Increased contraction of the stomach muscles would contribute to severe diarrhea, which would in turn render the patient dehydrated. As such, the physician should ensure close monitoring of the patient for adverse effects of the drug including diarrhea and administer an antagonist to reverse the action of bethanechol. Therefore, diagnosis of diarrhea should be part of the care plan due to the high risk associated with the use of the medication. 9. A 42 year old man was diagnosed with Parkinson disease 4 years ago. He is being treated with a drug regime that includes benztropine (Cogentin). Benztropine is an anticholinergic drug. What assessment data should be given to the patient? Discuss the potential side effects of benztropine that should be assessed for the patient? (5 marks) The assessment data presented to the patient should capture several details showing the test results from various tests used in Parkinson disease assessment such as the Parkinson activity scale, Time Up and Go, and physical performance test. Other assessment details include goniometric measurements, pain scales, vestibular screening, and sensory/pro-prioceptive testing results. IN addition, cognitive testing emerges as critical in assessing the patient’s ability to learn and retain movement enhancement strategies prior to development of the treatment approach. Benztropine as an anticholinergic drug used in the treatment of Parkinson disease triggers various side effects including constipation, dry mouth, and urinary retention. Urinary retention specifically arises from the antagonistic effects of the drug on muscarinic receptors located outside the brain. 10. Propranolol (Inderal) has been prescribed for a patient with hypertension. Due to the adverse effects related to this drug, the doctor would carefully monitor for which adverse effects? a) Bronchodilation b) Tachycardia c) Edema d) Bradycardia Explain? (3 marks) Propranolol (Inderal)is effective in slowing sinus heart rate in patients with inappropriate symptomatic sinus tachycardia and as a noncardioselective, it has no intrinsic sympathomimetic activity, but plays a major role in membrane stabilizing. It blocks adrenergic activation of calcium channels with consequent decrease in resting heart rate, and prolong sinus node recovery times, hence its application in the treatment of hypertension (Aschenbrenner & Venable, 2009). However, through its activity physicians should look out for adverse side effects such as severe bradycardia, bronchospam, and hypoglycemia in insulin dependent patients. Propranolol is used a adjuvant therapy with a sodium channel blocker forsupraventricular tachycardia. Central nervous system 11. A nurse is caring for a 72-year old patient taking gabapentin (Neutrontin) for a seizure disorder. Due to the patients age the nurse would establish what diagnosis related to the drugs common adverse effects? a) Risk for Deficient Fluid Volume b) Risk for Impaired Verbal Communication c) Risk for Constipation d) Risk for Falls Explain? (4 marks) The most likely side effect that could arise in a 72-year old patient taking gabapentin (Neutrontin) for a seizure disorder is constipation. Gabapentin is associated with several side effects including dizziness, fatigue, agitation and a lethargic confusion state state without seizures. Gabapentin may bind to ill-defined amino acid transporters as well as inhibit GABA synthesis with consequent negative impact on metabolism (King & Brucker, 2010). Discontinuation of the medication is often considered for persistent or troublesome complications. 12. Which of the following medications may be used to treat partial seizures? (Select all that apply) a) Phenytoin (Dilantin) b) Valproic acid (Depakene) c) Diazepam (Valium) d) Carbamazepine (Tegretol) e) Ethosuximide (Zarontin) Explain?(5 marks) Diazepam may be used in the treatment of partial seizure although the drug is sold as a clorazepate as a prodrug which is converted to an active metabolite of diazepam in the liver. Although primarily the drug is used for treatment of patients with anxiety disorders, it has been found to be useful as an adjunct drug for the treatment of partial seizures (Clark, Harvey, Finkel, Rey & Whalen, 2011). However, physicians should be aware of side effects such as drowsiness and lethargy as well as tolerance which can occur during long-term use of the drug. 13. The implications of the administration of haloperidol (Haldol) to a client exhibiting psychotic behavior include which of the following? a) Take the medication 1 hour before or 2 hours after antacids b) The incidence of extrapyramidal side effects (EPS) is high c) It is therapeutic if prescribed on an as-needed by the patient basis d) Haldol is contraindicated in Parkinson’s disease, seizure disorders, alcoholism and severe mental depression e) Crush the sustained-release form for easier swallowing Explain? (4 marks) The incidence of extrapyramidal side effects (EPS) is high and contraindicated in Parkinson’s disease, seizure disorders, alcoholism, and severe mental depression. Haloperidol causes significant extrapyramidal effects, as well as a low incidence of sedation, anticholinergic effects, and orthostatic hypotension (Brenner & Craig, 2012). In addition, a narrow margin exists between the therapeutically effective dose and the manifestation of extrapyramidal symptoms. In this case, the major implication in the administration of Haloperidal drug is cause of extrapyramidal effects. 14. A 16-year old girl has taken an overdose of citalopram (Celexa) and is brought to the emergency department of the hospital. What symptoms would be expected for this patient? a) Seizures, hypertension, tachycardia, extreme anxiety b) Hypotension, bradycardia, hypothermia, sedation c) Miosis, respiratory depression, absent bowel sounds, hypoactive reflexes d) Manic behavior, paranoia, delusions, tremors Explain? (3 marks) A 16-year old girl has taken an overdose of citalopram (Celexa) would show the following symptoms. a) Seizures, hypertension, tachycardia, extreme anxiety. This can be attributed to the mechanism of action that the drug follows with the reaction being complicated by the overdose. 15. When monitoring a client for early signs of lithium (Eskalith) toxicity. Which symptoms, if present, may indicate that toxicity is developing? a) Persistent GI upset (eg. Nausea, vomiting) b) Confusion c) Increased urination d) Convulsions e) Ataxia Explain? (3 marks) Persistent GI upset (eg. Nausea, vomiting) may indicate that toxicity is developing. Other symptoms include diarrhea, vomiting, slurred speech, mental confusion, course hand tremors, muscle weakness and incoordination, dizziness, bradycardia, and difficulty in walking (Sadock, Kaplan & Sadock, 2007). Cardiovascular system 16. The client is taking atenolol (Tenormin) and doxazosin (Cardura). What is the rationale for combining two anti-hypertensive drugs? a) The blood pressure will decrease faster b) Lower doses of both drugs may be given with fewer adverse effects c) There is less daily medication dosing d) Combination therapy will treat the patients other medical conditions Explain?(4 marks) The blood pressure will decrease faster when atenolol (Tenormin) and doxazosin (Cardura) are combined. This is because the two drugs are synergistic with doxazosin (Cardura) blocking receptors, causing peripheral vasodilation, thus decreasing BP while Atenilol (Tenormin)blocks beta receptors, thereby decreasing heart rate and cardiac output as well blocks renin release by the kidney (White, Duncan & Baumle ). 17. A client with significant hypertension unresponsive to other medications is given a prescription for hydralazine (Apresoline). An additional prescription of propranolol (Inderal) is also given to the client. The client inquires why two drugs are needed. Explain why the two drugs are prescribed for the client? a) Giving the two drugs together will lower the blood pressure even more than just one alone b) The hydralazine may cause tachycardia and the propranolol will help keep the heart rate within normal limits. c) The propranolol is to prevent lupus erythematosus from developing d) Direct-acting vasodilators such as hydralazine cause fluid retention and the propranolol will prevent excessive fluid buildup. e) Explain?(4 marks) Giving the two drugs together will lower the blood pressure even more than just one alone. Hydralazine is important for moderately hypertensive patients whose blood pressure is not well controlled either by diuretics or by drugs that interfere with the sympathetic nervous system. Combination of a diuretic, β-blocker, and hydralazine ensures that the chief determinants of blood pressure are affected including cardiac output (B-blocker), plasma volume (diuretic), and peripheral vascular resistance (hydralazine) (Craig & Stitzel, 2004). 18. Verapamil (Calan, Covera-HS, Verelan) should be used with extra caution or is contraindictated in clients with which cardiovascular condition? a) Hypertension b) Tachycardia c) Heart failure d) Angina e) Explain?(3 marks) Tachycardia Verapamil (Calan, Covera-HS, Verelan) is contraindictated in patients in severe LV dysfunctions, hypotension, cardiogenic shock, and in patients with ventricular tachycardia. 19. A patient is started on amiodarone (Cordarone, Pacerone) for cardiac dysrhythmias. This patient is also on digoxin (Digitek, Lanoxin, Lanoxicaps), warfarin (Coumadin), and insulin. What conditions should the patient be advised and monitored? Explain. The patient should be monitored for implications associated with the digoxin such as high calcium, which may lead to digoxin toxicity, and abdominal pain (Craig & Stitzel, 2004). Warfarin toxicity can lead to hemorrhage and thus its levels should be monitored strictly. Interaction of the two drugs should also be monitored to alleviate possible adverse effects from the interaction of the two drugs. (4 marks) 20. A patient with chest pain has been given diltiazem (Cardizem) IV for a heart rate of 118 beats per minute. Blood pressure at this time is 100/60mmHg. What precautions are required for this patient? Explain?(4 marks) Diltiazem produces electrophysiologic effects leading to consistent slowering of the heart rate. Intravenous infusion of diltiazem results into 20% decrease in heart rate in patients and as such, precautions should be taken prevent possible heart failure due to extreme lowering of the heart rate (Podrid & Kowey, 2001). The drug infusion must be controlled and the patient closely monitored to avoid reduction of the patient’s heart rate to an abnormal levels. References Aschenbrenner, D & Venable, S. (2009). Drug therapy in nursing. New York, NY: Lippincott Williams & Wilkins. Brenner, G & Craig, S. (2012). Pharmacology. London: Elsevier Health Sciences. Bullock, S. & Manias, E. (2011). Fundamentals of pharmacology, (6th ed.) Sydney, Pearsons Education Australia. Ciccone, C. (2007). Pharmacology in rehabilitation. London: F.A. Davis. Clark, M., Harvey, R., Finkel, R., Rey, J & Whalen, K. (2011).Pharmacology. New York, NY: Lippincott Williams & Wilkins. Craig, C & Stitzel, R. (2004). Modern pharmacology with clinical applications. New York, NY: Lippincott Williams & Wilkins. King, T & Brucker, M. (2010). Pharmacology for women’s health. New York, NY: Jones & Bartlett Publishers. Podrid, P & Kowey, P. (2001). Cardiac arrhythmia: Mechanisms, diagnosis, and management. New York, NY: Lippincott Williams & Wilkins. Rosenfield, G & Loose, D. (2007). Pharmacology. New York, NY: Lippincott Williams & Wilkins. Sadock, B., Kaplan, H & Sadock, V. (2007). Kaplan & Sadock’s synopsis of psychiatry: Behavioral sciences/Clinical psychiatry. New York, NY: Lippincott Williams & Wilkins. Read More