Chapter 32: Drug Therapy to Decrease Histamine Effects and Allergic Response

A client receives diphenhydramine orally. The nurse would expect this drug to begin acting within which time frame? a. 15 to 30 minutes b. 30 to 45 minutes c. 45 to 60 minutes d. 60 to 75 minutes

a. 15 to 30 minutes The onset of oral diphenhydramine is 15 to 30 minutes.

A client has begun taking an antihistamine for the treatment of seasonal allergies. What dietary guidelines should the nurse provide to the client? a. Avoid drinking alcohol while taking antihistamines b. Avoid grapefruit juice until at least 48 hours after treatment is complete c. Increase intake of foods that are high in vitamin C d. Eat several small meals instead of three larger meals in case of GI upset

a. Avoid drinking alcohol while taking antihistamines Alcohol is contraindicated during treatment with antihistamines due to their sedative effects that can be compounded by alcohol. There is no need to change the client's eating schedule or to avoid grapefruit juice. Vitamin C intake does not need to be increased.

A nurse is describing the action of a prescribed antihistamine to a client. The nurse is describing which medication, by explaining that the drug elicits its antihistamine effects by nonselectively binding to central and peripheral H1 receptors? a. Diphenhydramine b. Cetirizine c. Fexofenadine d. Loratadine

a. Diphenhydramine Diphenhydramine is a first-generation antihistamine. First-generation antihistamines elicit their antihistamine effects by nonselectively binding to central and peripheral H1 receptors. Second-generation antihistamines, such as cetirizine, fexofenadine, and loratadine, elicit their effects by being selective for peripheral H1 receptors only.

A 76-year-old client has been prescribed an oral antihistamine. What adverse effect presents a priority safety concern for older adult clients? a. Drowsiness b. Dry mouth c. Nasal burning d. Nonproductive cough

a. Drowsiness Older adults are more likely to experience anticholinergic effects (dryness of mouth, nose, throat), dizziness, sedation, hypotension, and confusion from the use of antihistamines. Drowsiness and sedation present the greatest safety concerns compared to other effects such as dry mouth and nonproductive cough. Nasal burning may occur due to nasal spray use.

What factors contribute to elderly clients being at higher risk of injury while taking antihistamines? Select all that apply: a. Hearing loss b. Steady gait c. Visual impairment d. Hypertension e. Diabetes

a. Hearing loss c. Visual impairment Elderly clients are more likely to experience injury from dizziness because with age comes increase risk for falls due to sensorimotor deficits (hearing loss, visual impairment), or unsteady gait.

A 74-year-old male client is diagnosed with hypertension, hyperlipidemia, angina, and gout. He presents to the health care provider's office with reports of seasonal allergies. His daughter has diphenhydramine at home, and he asks if it is safe for him to take it. The nurse is concerned because first-generation antihistamines may cause what adverse effects in older adults? (Select all that apply.) a. Hypotension b. Hypertension c. Syncope d. Myocardial hypoxia e. Pulmonary edema

a. Hypotension c. Syncope First-generation antihistamines (e.g., diphenhydramine) may cause confusion (with impaired thinking, judgment, and memory), dizziness, hypotension, sedation, syncope, unsteady gait, and paradoxical CNS stimulation in older adults. Pulmonary edema is not a side effect of first-generation antihistamines.

What hospital procedure has the greatest potential to cause an anaphylactoid reaction? a. administration of contrast media for diagnostic tests b. administration of low molecular weight heparin c. administration of bronchodilators by nebulizer d. administration of intravenous fluids rapidly

a. administration of contrast media for diagnostic tests Contrast media for radiologic diagnostic tests are often implicated in anaphylactoid reactions. The other options present a lesser risk for the development of an anaphylactoid reaction.

The nursing instructor is explaining the four types of allergic reaction to the nursing students. The instructor explains that allergic rhinitis is a a. type I hypersensitivity reaction. b. type II hypersensitivity reaction. c. type III hypersensitivity reaction.. d. type IV hypersensitivity reaction.

a. type I hypersensitivity reaction. Allergic rhinitis is a type I hypersensitivity reaction to inhaled allergens.

A 75-year-old client comes to the office reporting increased tiredness and confusion. The nurse obtains a full medication history. The client's current medications include lisinopril 20mg QD, alprazolam 0.25mg PRN, glyburide 5mg BID, acetaminophen 500 mg Q6 hours, and diphenhydramine 25 mg QD. Which medications could be causing the client's increased tiredness and confusion? Select all that apply: a. Lisinopril b. Alprazolam c. Glyburide d. Acetaminophen e. Diphenhydramine

b. Alprazolam e. Diphenhydramine Elderly clients experience more side effects from antihistamines, including sedation. Diphenhydramine is a first-generation antihistamine, which are generally more sedating than second-generation antihistamines. Also, alprazolam causes CNS depression that may be worsened by the diphenhydramine.

What type of antihistamine is typically preferred for older adults? a. First-generation b. Second-generation c. Neither type is preferred over the other. d. Antihistamines are contraindicated in older adults.

b. Second-generation Second-generation antihistamines are typically preferred for older adults because they lack some of the adverse effects associated with the first-generation versions. First-generation antihistamines have several adverse effects (e.g., sedation and confusion) that can be mistaken for senility or depression in older adults. Such effects may be more severe in patients who take anticholinergic drugs, such as some antiparkinson medications. Additionally, patients with prostatic hypertrophy may have difficulty voiding when taking first-generation antihistamines.

The health care provider has prescribed medication to prevent posttransfusion reaction in a client with a history of the disorder. Which medication would the nurse anticipate being administered? a. Epinephrine b. Furosemide c. Diphenhydramine d. Ibuprofen

c. Diphenhydramine A client who is having a blood transfusion or a diagnostic test may receive diphenhydramine, often by injection and usually as a single dose, to prevent allergic reactions. Epinephrine would be given for an acute reaction. Furosemide is a diuretic. Ibuprofen is given for pain or fever.

A female client is prescribed a first-generation antihistamine for her allergies. The nurse would expect her to experience what adverse effect? a. Diarrhea b. Incontinence c. Dry mouth d. Slurred speech

c. Dry mouth First-generation antihistamines have substantial anticholinergic effects; therefore, they may cause dry mouth, urinary retention, constipation, and blurred vision.

Second-generation antihistamines were developed to remove the sedation of first generation drugs. Which of the following antihistamines is a second-generation drug? a. Dexchlorpheniramine b. Chlorpheniramine c. Fexofenadine d. Diphenhydramine

c. Fexofenadine Fexofenadine is a second-generation antihistamine. Diphenhydramine, chlorpheniramine, and dexchlorpheniramine are first-generation antihistamines.

The health care provider has ordered promethazine (Phenergan) for a client who is having a severe allergic reaction. The nurse is aware that this medication is also used to treat what condition? a. Central nervous system depression b. Hypotension c. Nausea and vomiting d. Joint pain

c. Nausea and vomiting Promethazine is most commonly used in the treatment of nausea and vomiting.

A 15-year-old patient is prescribed an antihistamine for allergic rhinitis. However, antihistamines used to treat allergic reactions may themselves cause allergy. The nurse needs to educate the patient to be aware of symptoms suggesting allergy. Which of the following is an allergic reaction to antihistamines? a. Dryness of mouth b. Drowsiness and sedation c. Skin rash and urticaria d. Disturbed coordination

c. Skin rash and urticaria The nurse should inform the patient that skin rash and urticaria could occur as allergic reactions to antihistamines. Dryness of mouth, drowsiness, sedation, and disturbed coordination may occur as dose-related side effects of the drug but are not due to any allergic reaction.

Combining first-generation antihistamines with sedating agents can result in what adverse effect? a. Myocardial infarction b. Hypertensive crisis c. Liver failure d. Respiratory depression

d. Respiratory depression First-generation antihistamines have sedating properties. Combining them with other sedating agents, such as alcohol, can cause additive CNS depression, leading to lethargy, stupor, respiratory depression, coma, and death.

When developing the teaching plan for a client receiving an antihistamine, which would the nurse include? (Select all that apply.) a. Advising the client to avoid alcohol consumption b. Using sugarless candies or lozenges to combat dry mouth c. Stopping the drug after 3 days if no relief is obtained d. Encouraging the client to engage in usual activities such as driving

a. Advising the client to avoid alcohol consumption b. Using sugarless candies or lozenges to combat dry mouth When taking an antihistamine, the nurse needs to inform the client to take the drug on an empty stomach, 1 hour before or 2 hours after meals, use sugarless candies to combat dry mouth, to read the labels of OTC medications because they may contain the same ingredient or alcohol, which could increase the risk of adverse effects or toxicity, and to avoid alcohol intake to prevent excess CNS effects.

What is one of the benefits related to second generation antihistamine administration in older adults? a. They do not impair thinking. b. They reduce the number of falls in clients diagnosed with osteoporosis. c. They increase the ability of clients with dementia to perform ADLs. d. They do not affect oxygenation.

a. They do not impair thinking. Second-generation antihistamines should be used for older adults. They are much safer because they do not impair consciousness, thinking, or ability to perform activities of daily living (e.g., driving a car or operating various machines).

A client's drug regimen includes diphenhydramine. What potential indications may this drug be used for? Select all that apply. a. Urticaria b. Vasomotor rhinitis c. Productive cough d. Motion sickness e. Angioedema

a. Urticaria b. Vasomotor rhinitis d. Motion sickness e. Angioedema Diphenhydramine is used for the symptomatic relief of perennial and seasonal rhinitis, vasomotor rhinitis, allergic conjunctivitis, urticaria, and angioedema; it is also used for treating motion sickness and parkinsonism, as a nighttime sleep aid, and to suppress cough. It would not be used to treat a productive cough, because it is not an expectorant.

What medication should be prescribed to minimize the risk associated with a blood transfusion for a client with a history of a previous transfusion reaction? a. diphenhydramine b. epinephrine c. clemastine d. cetirizine

a. diphenhydramine A client who is having a blood transfusion or a diagnostic test may receive diphenhydramine, often by injection and usually as a single dose, to prevent allergic reactions. Epinephrine is the drug of choice for treating severe anaphylaxis once it has occurred. Clemastine is prescribed for allergic rhinitis and urticaria. Cetirizine is prescribed for the management of seasonal allergies.

A client administers diphenhydramine to their 9-year-old child, who experiences seasonal allergies, before a baseball game. What may the child experience if a paradoxical effect to the medication occurs? a. excitation b. exacerbation of allergic symptoms c. decreased mental alertness d. poor reflexes

a. excitation First-generation antihistamines (e.g., diphenhydramine) commonly cause drowsiness and decreased mental alertness. Excitation is a paradoxical effect that occasionally occurs, especially in children. Diphenhydramine isn't associated with exacerbation of allergic symptoms or an effect on reflexes.

A client is in the clinic for seasonal allergic rhinitis. Loratadine (Claritin) is prescribed. Which statement will the nurse include when providing education concerning this drug? a. "Be sure to take this medication on a full stomach." b. "Determine if the drug is going to make you drowsy before you drive." c. "You should take the medication twice a day." d. "This drug has to be taken every 4 to 6 hours."

b. "Determine if the drug is going to make you drowsy before you drive." Loratadine (Claritin) is a second-generation antihistamine and does not usually cause drowsiness like the first-generation medications; however, the client should take it for at least a day to determine the drug's effect before driving. Loratadine should be taken on an empty stomach to increase absorption. The drug is taken only once a day. Brompheniramine, a nonselective H1 blocker (first-generation antihistamine) is taken every 4 to 6 hours. Fexofenadine can be taken twice daily.

The nurse is providing instructions to a client who will be taking second-generation antihistamines at home. Which statement by the client indicates a need for further instruction? a. "If I miss a dose of medication, I will wait until the next scheduled time to take the medication." b. "I will take this medication with apple juice." c. "I will be careful to take the medication exactly as it comes." d. "I will check the prescription bottle and follow the directions carefully."

b. "I will take this medication with apple juice." Fexofenadine and related drugs should not be taken with fruit juice.

The nurse is providing education to a client regarding the use of an over-the-counter (OTC) antihistamine. Which client statement demonstrates a need for additional teaching? a. "I take the medication to manage my itchy, watery eyes." b. "When I feel a cold coming on, I know to take an antihistamine." c. "When I know I'm going to spend time outdoors, I take an antihistamine." d. "I always need an antihistamine when I visit family members who own pets."

b. "When I feel a cold coming on, I know to take an antihistamine." Rhinitis is a very common disorder characterized by nasal congestion, itching, sneezing, and watery drainage. Itching of the throat, eyes, and ears often occurs as well. These symptoms may occur when coming in contact with certain seasonal plant pollens or animal dander. Studies have demonstrated that although antihistamines relieve symptoms of allergic rhinitis, antihistamine are not successful or recommended for treatment of the common cold.

Which client is most likely to benefit from the administration of a nasal steroid? a. A client with an acute sinus infection b. A client who has chronic allergic rhinitis c. A client who is recovering from a tonsillectomy d. A client who has a deviated nasal septum

b. A client who has chronic allergic rhinitis Because nasal steroids block the inflammatory response, their use is contraindicated in the presence of acute infections. The most common reason they are prescribed is for the treatment of allergic rhinitis or to relieve inflammation after the removal of nasal polyps. Nasal steroids are not used for treatment after a tonsillectomy or for clients with a deviated nasal septum.

When considering possible side effects, which client should be considered for a prescription of cetirizine rather than diphenhydramine? a. A 42-year-old client diagnosed with an acid reflux disorder b. Any adult older than 56-years-of age. c. A child younger than 10-years-of age d. A 36-year-old diagnosed with acute gastritis

b. Any adult older than 56-years-of age. Unlike the first-generation H1 receptor antagonists like diphenhydramine, the second-generation H1 receptor antagonists like cetirizine do not readily enter the brain from the blood but bind preferentially to peripheral rather than central H1 receptors. This selectivity significantly reduces the occurrence of adverse drug reactions of the central nervous system, but drowsiness and CNS depression may occur but likely to a lessening degree. In general, second-generation antihistamines are much safer than first-generation agents for older adults because they are less likely to impair consciousness, thinking, or ability to perform activities of daily living (e.g., driving a car or operating various machines). Young children may experience paradoxical excitement after receiving therapeutic dosages of diphenhydramine and other first-generation H1 receptor antagonists. For safe use in children, close supervision and appropriate dosages are necessary. Cetirizine may be used in children six-months of age and older. Neither acid reflux nor acute gastritis precludes the use of diphenhydramine.

A client reports nasal congestion, sneezing, watery drainage from the nose, and itching of the throat, eyes, and ears. The nurse recognizes that these are consistent with what disorder? a. sinus infection b. allergic rhinitis c. anaphylaxis d. a histamine reaction

b. allergic rhinitis Allergic rhinitis is inflammation of nasal mucosa caused by a type I hypersensitivity reaction to inhaled allergens. It is a very common disorder characterized by nasal congestion, itching, sneezing, and watery drainage. Itching of the throat, eyes, and ears often occurs as well. The other conditions would present with a different set of signs and symptoms.

The nurse is caring for an adult client with a new prescription for cetirizine. To reduce the risk for drug-drug interactions, the nurse should ask the client about current therapy if there is a history of what disorder? a. type 2 diabetes b. asthma c. frequent heartburn d. depression

b. asthma Theophylline, a drug that is occasionally prescribed for the treatment of asthma, is known to interact with and to decrease the clearance of cetirizine. Potentially significant interactions may exist, requiring adjustment in dose or frequency, additional monitoring, or selection of an alternate drug. There is currently no research to suggest drug interactions between cetirizine and medications prescribed for type 2 diabetes, heartburn, or depression.

First-generation H1 receptor antagonists are chemically diverse antihistamines that bind to both central and peripheral H1 receptors and can cause CNS depression or stimulation. Which of the following are examples of these drugs? Choose all that apply. a. azelastine (Astelin) b. chlorpheniramine (Chlor-Trimeton) c. hydroxyzine (Vistaril) d. diphenhydramine (Benadryl) e. promethazine (Phenergan)

b. chlorpheniramine (Chlor-Trimeton) c. hydroxyzine (Vistaril) d. diphenhydramine (Benadryl) e. promethazine (Phenergan) Azelastine (Astelin) is the only second-generation antihistamine listed.

A client has been prescribed a first-generation antihistamine. What adverse effects should the nurse describe during client teaching? Select all that apply. a. sense of euphoria b. urinary retention c. diarrhea d. blurred vision e. dry mouth

b. urinary retention d. blurred vision e. dry mouth First-generation antihistamines have substantial anticholinergic effects (e.g., cause dry mouth, urinary retention, constipation, blurred vision). These drugs may cause central nervous system (CNS) stimulation (anxiety, agitation) with excessive doses, especially in children. Neither diarrhea nor euphoria is associated with first-generation antihistamine therapy.

Your client has allergic rhinitis. When providing client education for information about the disease process, you would include all of the following EXCEPT: a. Allergic rhinitis that is not effectively treated may lead to chronic fatigue. b. Allergic rhinitis that is not effectively treated may lead to postnasal drip. c. Allergic rhinitis that is not effectively treated may lead to improved sleeping. d. Allergic rhinitis that is not effectively treated may lead to sinus infections.

c. Allergic rhinitis that is not effectively treated may lead to improved sleeping. Allergic rhinitis that is not effectively treated may lead to chronic fatigue, impaired ability to perform usual activities of daily living, difficulty sleeping, sinus infections, postnasal drip, cough, and headache. In addition, this condition is a strong risk factor for asthma.

The pharmacology instructor is discussing the adverse effects of diphenhydramine. Which is not one of these effects? a. Dry mouth b. Blurred vision c. Excessive salivation d. Drowsiness

c. Excessive salivation Adverse effects of first-generation antihistamines include urinary retention, drowsiness or sedation, dry mouth, blurred vision, and gastrointestinal distress.

Mr. Zee is prescribed an inhaled nasal steroid to relieve his symptoms associated with seasonal allergies. What is true about inhaled nasal steroids? a. Inhaled nasal steroids do not have any adverse effects. b. Inhaled nasal steroids produce a significant systemic effect. c. Inhaled nasal steroids are more effective than oral medications in treating the global symptoms associated with allergies. d. Inhaled nasal steroids are used only to treat seasonal allergies.

c. Inhaled nasal steroids are more effective than oral medications in treating the global symptoms associated with allergies. Inhaled nasal steroidal preparations are used to treat seasonal or perennial allergic rhinitis. In fact, studies indicate that they are superior to oral antihistamines for alleviating nasal, eye, and global allergy symptoms. Common adverse effects of inhaled nasal steroids include a burning or itching sensation and a drying effect on the nasal mucosa. By delivering steroids directly to the nasal passage, inhaled nasal steroids maximize the beneficial therapeutic effects of corticosteroids while minimizing their potential systemic adverse effects, although systemic adverse effects may still occur during long-term or high-dose therapy.

Which statement accurately describes an aspect of serum sickness? a. It can develop in 1 to 2 days. b. Sensitization to the antigen will diminish the reaction. c. Is a delayed hypersensitivity reaction. d. Symptoms include sensitivity to light resulting in optic pain.

c. Is a delayed hypersensitivity reaction. Serum sickness is a delayed hypersensitivity reaction most often caused by drugs, such as antimicrobials. In addition, many drugs that produce anaphylaxis also produce serum sickness. With initial exposure to the antigen, symptoms usually develop within 7 to 10 days and include urticaria, lymphadenopathy, myalgia, arthralgia, and fever. The reaction usually resolves within a few days but may be severe or even fatal. With repeated exposure to the antigen, after prior sensitization of the host, accelerated serum sickness may develop within 2 to 4 days, with similar but often more severe signs and symptoms.

Pseudoephedrine (Sudafed) is prescribed for a client suffering from nasal and sinus congestion. What is the most important assessment the nurse should complete before the client leaves the clinic to purchase the medication? a. Observe for swelling in nasal passages. b. Ask about history of hay fever. c. Obtain the client's blood pressure. d. Ask about nausea and vomiting.

c. Obtain the client's blood pressure. Sudafed is a decongestant. Decongestants are used cautiously in clients with a history of hypertension because of the vasoconstrictive effects of the drug. Swelling of nasal passages is a symptom of congestion. A history of hay fever is not a contraindication to taking decongestants. Nausea and vomiting are potential adverse effects but are not as important as assessing blood pressure.

A 62-year-old client has been prescribed an antihistamine to alleviate vasomotor rhinitis. The client reports gastric irritation after taking the tablet. Which instructions should the nurse provide to help alleviate the client's condition? a. Drink ample water before taking the tablet. b. Take an antacid before the tablet. c. Take the tablet with food. d. Take the tablet one hour before food.

c. Take the tablet with food. If the client has gastric irritation following ingestion of the antihistamine, the nurse should instruct the client to take the tablet with food and not before food. Taking an antacid before the tablet may reduce the absorption of the antihistamine. Drinking ample water before taking the tablet will not help to alleviate the patient's condition.

A 20-year-old woman calls the clinic at 5 PM and reports to the nurse that she forgot to take her morning dose of fexofenadine (Allegra). She usually takes her evening dose at 8 PM. She wants to know what she should do. The nurse will instruct her to a. double her evening dose. b. skip the evening dose and start back in the morning. c. forget about the morning dose and take the evening dose. d. take the morning dose now and the evening dose at the regular time.

c. forget about the morning dose and take the evening dose. Since it is only 3 hours until her evening dose, the nurse will instruct her to forget about the morning dose and take the evening dose as scheduled. It is not advisable to take two doses at the same time, and there is no need to skip the evening dose as well.

The nurse regularly assesses clients for risk of anaphylactic reaction to prescribed medications. The nurse is aware that such reactions most commonly occur with what type of medication? a. opioid analgesics b. local anesthestics c. penicillins d. vaccines

c. penicillins Virtually all drugs have been implicated in anaphylactic reactions but penicillins are a common offender. Less common causes include anesthetics (local and general), opioid analgesics, skeletal muscle relaxants used with general anesthetics, and vaccines

Antihistamines are not routinely used in the critically ill client population. Diphenhydramine, however, may be administered to a critically ill client for which reason? a. for sedation. b. prior to a blood test. c. prior to a blood transfusion. d. prior to discharge from the intensive care unit.

c. prior to a blood transfusion. Diphenhydramine may be given by injection, usually as a single dose, to a critically-ill client who is having a blood transfusion or a diagnostic test to prevent allergic reactions. It is not given for sedation in the critically-ill, or prior to blood tests or discharge from the unit.

The nurse is teaching a client about the potential for allergic drug reaction. What statement made by a client suggests a need for further teaching? a. "All drugs have the potential to cause an allergic reaction." b. "The additives that are in drugs can also cause allergic reactions." c. "Virtually any drug may induce an immunologic response in a susceptible person." d. "If you didn't have allergies as a child, you won't develop allergies later in life."

d. "If you didn't have allergies as a child, you won't develop allergies later in life." Drug allergies can develop later in life, though many appear at a young age. All the other options contain accurate statements.

A client exhibiting signs and symptoms of the common cold asks the nurse if taking an antihistamine would be helpful. What is the nurse's best response? a. Yes, but be sure to use a brand that mentions 'cold remedy' on the packaging. b. Yes, but it's important to monitor for adverse effects. c. Antihistamines can be helpful when they're combined with an antibiotic. d. Antihistamines are not recommended for treating a cold.

d. Antihistamines are not recommended for treating a cold. Although antihistamines are popular over-the-counter drugs, studies have demonstrated that they are not successful or recommended for the treatment of the common cold. An antibiotic should not be prescribed for the treatment of the common cold, which is a viral disorder.

A male client presents to the emergency department with symptoms of a gastrointestinal bleed. The health care provider orders a blood transfusion. The client has a history of anaphylaxis. The provider orders the administration of what drug before the blood transfusion? a. Cetirizine b. Desloratadine c. Azelastine d. Diphenhydramine

d. Diphenhydramine Diphenhydramine may be given by injection, usually as a single dose, to a client who is having a blood transfusion or a diagnostic test, to prevent allergic reactions. Hydroxyzine or promethazine may be given by injection for nausea and vomiting or to provide sedation, but they are not usually the first drugs of choice for these indications.

A patient with allergic rhinitis is prescribed an antihistamine. The nurse instructs the patient to suck on a sugarless hard candy to prevent which condition? a. Drowsiness and sedation b. Thickening of the bronchial secretion c. Altered sensation of taste d. Dryness of the oral mucosa and the throat

d. Dryness of the oral mucosa and the throat The nurse should instruct the patient to suck on a sugarless hard candy to prevent dryness of the oral mucosa and the throat seen as a side effect of antihistamine therapy. Sucking on candy does not relieve drowsiness, sedation, and thickening of the bronchial mucosa seen with antihistamine therapy. Altered sense of taste does not occur with most antihistamines.

Antihistamines are used frequently in the home care setting for the treatment of allergies. Which of the following is most likely to be a responsibility of the nurse caring for a patient who is taking antihistamines for this indication? a. Removing environmental allergens b. Administering the antihistamine c. Ensuring that the patient uses a second-generation antihistamine d. Helping the patient identify environmental allergens

d. Helping the patient identify environmental allergens In any care setting, the nurse assists the patient in identifying and avoiding factors that precipitate hypersensitivity reactions. Patients are likely able to administer their own medications. Although second-generation antihistamines are preferred for older patients, first-generation drugs are still used widely and safely.

A patient with vasomotor rhinitis has been prescribed an antihistamine. The patient is eager to know whether the prescribed antihistamine may cause excessive sedation. Which of the following antihistamines has very little sedative effect? a. Brompheniramine b. Clemastine c. Chlorpheniramine d. Loratadine

d. Loratadine The nurse should assure the patient that loratadine has very little sedative effect. Loratadine is a second-generation antihistamine with little effect on central nervous system (CNS) depression. Brompheniramine, clemastine, and chlorpheniramine are first-generation antihistamines. Sedation is seen more often with first-generation antihistamines.

When describing the effects of second-generation antihistamines, which would the nurse address as being decreased? a. Hypersensitivity b. Dry mouth c. Gastrointestinal upset d. Sedation

d. Sedation The adverse effects most often seen with antihistamine use are drowsiness and sedation. However, second-generation antihistamines are less sedating in many people. The anticholinergic effects associated with both generations include drying of the respiratory and gastrointestinal mucous membranes, gastrointestinal upset and nausea, arrhythmias, dysuria, urinary hesitancy, and skin eruption and itching associated with dryness.

When caring for a patient with an allergic reaction following a blood transfusion, which of the following conditions should the nurse consider as a contraindication for antihistamine therapy? a. Open-angle glaucoma b. Bronchial asthma c. Impaired kidney function d. Stenosing peptic ulcer

d. Stenosing peptic ulcer The nurse should consider the presence of a stenosing peptic ulcer as a contraindication for antihistamine therapy. Closed-angle glaucoma and not open-angle glaucoma is another contraindication. Antihistamines are not contraindicated in bronchial asthma and impaired kidney function. They can be used with caution in such cases.

Second-generation H1 antagonists cause less CNS depression because they are selective for peripheral H1 receptors and because of which other property? a. They are excreted by the renal system. b. They are metabolized by the liver. c. They cross the blood-brain barrier. d. They do not cross the blood-brain barrier.

d. They do not cross the blood-brain barrier. Second-generation H1 antagonists cause less CNS depression because they are selective for peripheral H1 receptors and do not cross the blood-brain barrier.

What causes the inflammation of nasal mucosa that is seen in allergic rhinitis? a. Type III hypersensitivity reaction to inhaled allergens b. Type II hypersensitivity reaction to inhaled allergens c. Type IV hypersensitivity reaction to inhaled allergens d. Type I hypersensitivity reaction to Inhaled allergens

d. Type I hypersensitivity reaction to Inhaled allergens Allergic rhinitis is inflammation of nasal mucosa caused by a type I hypersensitivity reaction to inhaled allergens