Antiarrhythmic Drugs
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Antiarrhythmic Drugs
Definition
Antiarrhythmic drugs are medicines that correct irregular heartbeats and slow down hearts that beat too fast.
Purpose
Normally, the heart beats at a steady, even pace. The pace is controlled by electrical signals that begin in one part of the heart and quickly spread through the whole heart. If something goes wrong with this control system, the result may be an irregular heartbeat, or an arrhythmia. Antiarrhythmic drugs correct irregular heartbeats, restoring the normal rhythm. If the heart is beating too fast, these drugs will slow it down. By correcting these problems, antiarrhythmic drugs help the heart work more efficiently.
Description
Antiarrhythmic drugs are available only with a physician's prescription and are sold in capsule (regular and extended release), tablet (regular and extended-release), and injectable forms. Commonly used antiarrhythmic drugs are disopyramide (Norpace, Norpace CR), procainamide (Procan SR, Pronestyl, Pronestyl-SR), and quinidine (Cardioquin, Duraquin, Quinidex, and other brands). Do not confuse quinidine with quinine, which is a related medicine with different uses, such as relieving leg cramps.
Recommended dosage
The recommended dosage depends on the type of antiarrhythmic drug and other factors. Doses may be different for different patients. Check with the physician who prescribed the drug or the pharmacist who filled the prescription for the correct dosage.
Always take antiarrhythmic drugs exactly as directed. Never take larger or more frequent doses.
Do not stop taking this medicine without checking with the physician who prescribed it. Stopping it suddenly could lead to a serious change in heart function.
Antiarrhythmic drugs work best when they are at constant levels in the blood. To help keep levels constant, take the medicine in doses spaced evenly through the day and night. Do not miss any doses. If taking medicine at night interferes with sleep, or if it is difficult to remember to take the medicine during the day, check with a health care professional for suggestions.
Precautions
Persons who take these drugs should see their physician regularly. The physician will check to make sure the medicine is working as it should and will note any unwanted side effects.
Some people feel dizzy, lightheaded, or faint when using these drugs. This medicine may cause blurred vision or other vision problems. Because of these possible problems, anyone who takes these drugs should not drive, use machines or do anything else that might be dangerous until they have found out how the drugs affect them. If the medicine does cause vision problems, wait until vision is clear before driving or engaging in other activities that require normal vision.
Antiarrhythmic drugs make some people feel lightheaded, dizzy, or faint when they get up after sitting or lying down. To lessen the problem, get up gradually and hold onto something for support if possible.
Anyone taking this medicine should not drink alcohol without his or her physician's approval.
Some antiarrhythmic drugs may change the results of certain medical tests. Before having medical tests, anyone taking this medicine should alert the health care professional in charge.
Anyone who is taking antiarrhythmic drugs should be sure to tell the health care professional in charge before having any surgical or dental procedures or receiving emergency treatment.
Antiarrhythmic drugs may cause low blood sugar in some people. Anyone who experiences symptoms of low blood sugar should eat or drink a food that contains sugar and call a physician immediately. Signs of low blood sugar are:
- anxiety
- confusion
- nervousness
- shakiness
- unsteady walk
- extreme hunger
- headache
- nausea
- drowsiness
- unusual tiredness or weakness
- fast heartbeat
- pale, cool skin
- chills
- cold sweats
Antiarrhythmic drugs may cause dry mouth. To temporarily relieve the discomfort, chew sugarless gum, suck on sugarless candy or ice chips, or use saliva substitutes, which come in liquid and tablet forms and are available without a prescription. If the problem continues for more than 2 weeks, check with a physician or dentist. Mouth dryness that continues over a long time may contribute to tooth decay and other dental problems.
People taking antiarrhythmic drugs may sweat less, which can cause the body temperature to rise. Anyone who takes this medicine should be careful not to become overheated during exercise or hot weather and should avoid hot baths, hot tubs, and saunas. Overheating could lead to heat stroke.
Older people may be especially sensitive to the effects of antiarrhythmic drugs. This may increase the risk of certain side effects, such as dry mouth, difficult urination, and dizziness or lightheadedness.
Key terms
Anxiety — Worry or tension in response to real or imagined stress, danger, or dreaded situations. Physical reactions, such as fast pulse, sweating, trembling, fatigue, and weakness may accompany anxiety.
Arrhythmia — Abnormal heart rhythm.
Asthma — A disease in which the air passages of the lungs become inflamed and narrowed.
Emphysema — A lung disease in which breathing becomes difficult.
Glaucoma — A condition in which pressure in the eye is abnormally high. If not treated, glaucoma may lead to blindness.
Hallucination — A false or distorted perception of objects, sounds, or events that seems real. Hallucinations usually result from drugs or mental disorders.
Heat stroke — A severe condition caused by prolonged exposure to high heat. Heat stroke interferes with the body's temperature regulating abilities and can lead to collapse and coma.
Inflammation — Pain, redness, swelling, and heat that usually develop in response to injury or illness.
Myasthenia gravis — A chronic disease with symptoms that include muscle weakness and sometimes paralysis.
Palpitation — Rapid, forceful, throbbing, or fluttering heartbeat.
Prostate — A donut-shaped gland below the bladder in men that contributes to the production of semen.
Psoriasis — A skin disease in which people have itchy, scaly, red patches on the skin.
Systemic lupus erythematosus (SLE) — A chronic disease that affects the skin, joints, and certain internal organs.
Tourette syndrome — A condition in which a person has tics and other involuntary behavior, such as barking, sniffing, swearing, grunting, and making uncontrollable movements.
Tremor — Shakiness or trembling.
The antiarrhythmic drug procainamide can cause serious blood disorders. Anyone taking this medicine should have regular blood counts and should check with a physician if any of the following symptoms occur:
- dark urine
- yellow skin or eyes
- unusual bleeding or bruising
- dizziness
- hallucinations
- depression
Special conditions
People with certain medical conditions or who are taking certain other medicines may have problems if they take antiarrhythmic drugs. Before taking these drugs, be sure to let the physician know about any of these conditions:
ALLERGIES. Anyone who has had unusual reactions to an antiarrhythmic drug in the past should let his or her physician know before taking this type of medicine again. Patients taking procainamide should let their physicians know if they have ever had an unusual or allergic reaction to procaine or any other "caine-type" medicine, such as xylocaine or lidocaine. Patients taking quinidine should mention any previous reactions to quinine. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.
CONGESTIVE HEART DISEASE. Antiarrhythmic drugs may cause low blood sugar, which can be a particular problem for people with congestive heart disease. Anyone with congestive heart disease should be familiar with the signs of low blood sugar (listed above) and should check with his or her physician about what to do if such symptoms occur.
DIABETES. Antiarrhythmic drugs may cause low blood sugar, which can be a particular problem for people with diabetes. Anyone with diabetes should be familiar with the signs of low blood sugar (listed above) and should check with his or her physician about what to do if such symptoms occur.
PREGNANCY. The effects of taking antiarrhythmic drugs in pregnancy have not been studied in humans. In studies of laboratory animals, this medicine increased the risk of miscarriage. In addition, some women who have taken these drugs while pregnant have had contractions of the uterus (womb). Women who are pregnant or who may become pregnant should check with their physicians before taking this medicine. Women who become pregnant while taking this medicine should let their physicians know right away.
BREASTFEEDING. Antiarrhythmic drugs pass into breast milk. Women who are breastfeeding should check with their physicians before taking this medicine.
OTHER MEDICAL CONDITIONS. Before using anti-arrhythmic drugs, people with any of these medical problems should make sure their physicians are aware of their conditions:
- heart disorders such as structural heart disease or inflammation of the heart muscle
- congestive heart failure
- kidney disease
- liver disease
- diseases of the blood
- asthma or emphysema
- enlarged prostate or difficulty urinating
- overactive thyroid
- low blood sugar
- psoriasis
- glaucoma
- myasthenia gravis
- systemic lupus erythematosus
USE OF CERTAIN MEDICINES. Taking antiarrhythmic drugs with certain other drugs may affect the way the drugs work or may increase the chance of side effects.
Side effects
The most common side effects are dry mouth and throat, diarrhea, and loss of appetite. These problems usually go away as the body adjusts to the drug and do not require medical treatment. Less common side effects, such as dizziness, lightheadedness, blurred vision, dry eyes and nose, frequent urge to urinate, bloating, constipation, stomach pain, and decreased sexual ability, also may occur and do not need medical attention unless they do not go away or they interfere with normal activities.
More serious side effects are not common, but may occur. If any of the following side effects occur, check with the physician who prescribed the medicine as soon as possible:
- fever and chills
- difficult urination
- swollen or painful joints
- pain when breathing
- skin rash or itching
People who are especially sensitive to quinidine may have a reaction to the first dose or doses. If any of these side effects occur after taking quinidine, check with a physician immediately:
- dizziness
- ringing in the ears
- breathing problems
- vision changes
- fever
- headache
- skin rash
Other rare side effects may occur with any anti-arrhythmic drug. Anyone who has unusual symptoms after taking antiarrhythmic drugs should get in touch with his or her physician.
Interactions
Antiarrhythmic drugs may interact with other medicines. When this happens, the effects of one or both of the drugs may change or the risk of side effects may be greater. Anyone who takes antiarrhythmic drugs should let the physician know all other medicines he or she is taking. Among the drugs that may interact with antiarrhythmic drugs are:
- other heart medicines, including other antiarrhythmic drugs
- blood pressure medicine
- blood thinners
- pimozide (Orap), used to treat Tourette's syndrome
The list above does not include every drug that may interact with antiarrhythmic drugs. Be sure to check with a physician or pharmacist before combining antiarrhythmic drugs with any other prescription or nonprescription (over-the-counter) medicine.
Antiarrhythmic Drugs: Amiodarone Digoxin, Disopyramide, Flecainide, Lidocaine, Procainamide, Quinidine
Synonym/acronym: Amiodarone (Cordarone); Digoxin (Digitek, Lanoxicaps, Lanoxin); disopyramide (Norpace, Norpace CR); flecainide (flecainide acetate, Tambocor); lidocaine (Xylocaine); procainamide (Procanbid, Pronestyl, Pronestyl SR); quinidine (Quinidex Extentabs, quinidine sulface SR, quinidine gluconate SR).
Common use
To evaluate specific drugs for subtherapeutic, therapeutic, or toxic levels in treatment of heart failure and cardiac arrhythmias.
Specimen
Serum (1 mL) collected in a red-top tube.| Drug | Route of Administration | Recommended Collection Time |
|---|---|---|
| Amiodarone | Oral | Trough: immediately before next dose |
| Digoxin | Oral | Trough: 12–24 hr after dose |
| Never draw peak samples | ||
| Disopyramide | Oral | Trough: immediately before next dose |
| Peak: 2–5 hr after dose | ||
| Flecainide | Oral | Trough: immediately before next dose |
| Peak: 3 hr after dose | ||
| Lidocaine | IV | 15 min, 1 hr, then every 24 hr |
| Procainamide | IV | 15 min; 2, 6, 12 hr; then every 24 hr |
| Procainamide | Oral | Trough: immediately before next dose |
| Peak: 75 min after dose | ||
| Quinidine sulfate | Oral | Trough: immediately before next dose |
| Peak: 1 hr after dose | ||
| Quinidine gluconate | Oral | Trough: immediately before next dose |
| Peak: 5 hr after dose | ||
| Quinidine polygalacturonate | Oral | Trough: immediately before next dose |
| Peak: 2 hr after dose |
Normal findings
(Method: Immunoassay)
| Drug (Indication) | Therapeutic Range Conventional Units | Conversion to SI units | SI Units | Half-Life (hr) | Volume of Distribution (L/kg) | Protein Binding (%) | Excretion |
|---|---|---|---|---|---|---|---|
| Amiodarone | 0.5–2.5 mcg/mL | SI units = Conventional Units × 1.55 | 0.8–3.9 micromol/L | 250–1200 | 20–100 | 95–97 | 1° hepatic |
| Digoxin | 0.5–2 ng/mL | SI units = Conventional Units × 1.28 | 0.6–2.6 nmol/L | 20–60 | 7 | 20–30 | 1° renal |
| Disopyramide | 2.8–7 mcg/mL | SI units = Conventional Units × 2.95 | 8.3–20.6 micromol/L | 4–10 | 0.7–0.9 | 20–60 | 1° renal |
| Flecainide | 0.2–1 mcg/mL | SI units = Conventional Units × 2.41 | 0.5–2.4 micromol/L | 7–19 | 5–13 | 40–50 | 1° renal |
| Lidocaine | 1.5–5 mcg/mL | SI units = Conventional Units × 4.27 | 6.4–21.4 micromol/L | 1.5–2 | 1–1.5 | 60–80 | 1° hepatic |
| Procainamide | 4–10 mcg/mL | SI units = Conventional Units × 4.25 | 17–42 micromol/L | 2–6 | 2–4 | 10–20 | 1° renal |
| N-acetyl procainamide | 10–20 mcg/mL | SI units = Conventional Units × 4.25 | 42–85 micromol/L | 8 | 1° renal | ||
| Quinidine | 2–5 mcg/mL | SI units = Conventional Units × 3.08 | 6–15 micromol/L | 6–8 | 2–3 | 70–90 | Renal and hepatic |
Description
Cardiac glycosides are used in the prophylactic management and treatment of heart failure and ventricular and atrial arrhythmias. Because these drugs have narrow therapeutic windows, they must be monitored closely. The signs and symptoms of toxicity are often difficult to distinguish from those of cardiac disease. Patients with toxic levels may show gastrointestinal, ocular, and central nervous system effects and disturbances in potassium balance.
Important note: These medications are metabolized and excreted by the liver and kidneys and are therefore contraindicated in patients with hepatic or renal disease and cautiously advised in patients with renal impairment. Information regarding medications must be communicated clearly and accurately to avoid misunderstanding of the dose time in relation to the collection time. Miscommunication between the individual administering the medication and the individual collecting the specimen is the most frequent cause of subtherapeutic levels, toxic levels, and misleading information used in the calculation of future doses. If administration of the drug is delayed, notify the appropriate department(s) to reschedule the blood draw and notify the requesting health-care provider (HCP) if the delay has caused any real or perceived therapeutic harm. Many factors must be considered in effective dosing and monitoring of therapeutic drugs, including patient age, patient ethnicity, patient weight, interacting medications, electrolyte balance, protein levels, water balance, conditions that affect absorption and excretion, and the ingestion of substances (e.g., foods, herbals, vitamins, and minerals) that can either potentiate or inhibit the intended target concentration. Peak and trough collection times should be documented carefully in relation to the time of medication administration.
This procedure is contraindicated for
- N/A
Indications
- Assist in the diagnosis and prevention of toxicity
- Monitor compliance with therapeutic regimen
- Monitor patients who have a pacemaker, who have impaired renal or hepatic function, or who are taking interacting drugs
Potential diagnosis
| Level | Response |
|---|---|
| Normal levels | Therapeutic effect |
| Subtherapeutic levels | Adjust dose as indicated |
| Toxic levels | Adjust dose as indicated |
| Amiodarone | Hepatic impairment, older results |
| Digoxin | Renal impairment, CHF,* older adults |
| Disopyramide | Renal impairment |
| Flecainide | Renal impairment, CHF |
| Lidocaine | Hepatic impairment, CHF |
| Procainamide | Renal impairment |
| Quinidine | Renal and hepatic impairment, CHF, older adults |
Critical findings
Adverse effects of subtherapeutic levels are important. Care should be taken to investigate the signs and symptoms of too little and too much medication. Note and immediately report to the HCP any critically increased or subtherapeutic values and related symptoms.
Timely notification of a critical finding for lab or diagnostic studies is a role expectation of the professional nurse. The notification processes will vary among facilities. Upon receipt of the critical finding the information should be read back to the caller to verify accuracy. Most policies require immediate notification of the primary HCP, hospitalist, or on-call HCP. Reported information includes the patient’s name, unique identifiers, critical finding, name of the person giving the report, and name of the person receiving the report. Documentation of notification should be made in the medical record with the name of the HCP notified, time and date of notification, and any orders received. Any delay in a timely report of a critical finding may require completion of a notification form with review by Risk Management.
Signs and symptoms of pulmonary damage related to amiodarone toxicity include bronchospasm, wheezing, fever, dyspnea, cough, hemoptysis, and hypoxia. Possible interventions include discontinuing the medication, monitoring pulmonary function with chest x-ray, monitoring liver function tests to assess for liver damage, monitoring thyroid function tests to assess for thyroid damage (related to the high concentration of iodine contained in the medication), and electrocardiographic (ECG) monitoring for worsening of arrhythmia.
Signs and symptoms of digoxin toxicity include arrhythmias, anorexia, hyperkalemia, nausea, vomiting, diarrhea, changes in mental status, and visual disturbances (objects appear yellow or have halos around them). Possible interventions include discontinuing the medication, continuous ECG monitoring (prolonged P-R interval, widening QRS interval, lengthening Q-Tc interval, and atrioventricular block), transcutaneous pacing, administration of activated charcoal (if the patient has a gag reflex and central nervous system function), support and treatment of electrolyte disturbance, and administration of Digibind (digoxin immune Fab). The amount of Digibind given depends on the level of digoxin to be neutralized. Digoxin levels must be measured before the administration of Digibind. Digoxin levels should not be measured for several days after administration of Digibind in patients with normal renal function (1 wk or longer in patients with decreased renal function). Digibind cross-reacts in the digoxin assay and may provide misleading elevations or decreases in values depending on the particular assay in use by the laboratory.
Signs and symptoms of disopyramide toxicity include prolonged Q-T interval, ventricular tachycardia, hypotension, and heart failure. Possible interventions include discontinuing the medication, airway support, and ECG and blood pressure monitoring.
Signs and symptoms of flecainide toxicity include exaggerated pharmacological effects resulting in arrhythmia. Possible interventions include discontinuing the medication as well as continuous ECG, respiratory, and blood pressure monitoring.
Signs and symptoms of lidocaine toxicity include slurred speech, central nervous system depression, cardiovascular depression, convulsions, muscle twitches, and possible coma. Possible interventions include continuous ECG monitoring, airway support, and seizure precautions.
The active metabolite of procainamide is N-acetyl procainamide (NAPA). Signs and symptoms of procainamide toxicity include torsade de pointes (ventricular tachycardia), nausea, vomiting, agranulocytosis, and hepatic disturbances. Possible interventions include airway protection, emesis, gastric lavage, and administration of sodium lactate.
Signs and symptoms of quinidine toxicity include ataxia, nausea, vomiting, diarrhea, respiratory system depression, hypotension, syncope, anuria, arrhythmias (heart block, widening of QRS and Q-T intervals), asystole, hallucinations, paresthesia, and irritability. Possible interventions include airway support, emesis, gastric lavage, administration of activated charcoal, administration of sodium lactate, and temporary transcutaneous or transvenous pacemaker.
Amiodarone: Greater Than 2.5 mcg/mL (SI: Greater Than 3.9 micromol/L)
Digoxin: Greater Than 2.5 ng/mL (SI: Greater Than 3.2 nmol/L)
Disopyramide: Greater Than 7 mcg/mL (SI: Greater Than 20.6 micromol/L)
Flecainide: Greater Than 1 mcg/mL (SI: Greater Than 2.41 micromol/L)
Lidocaine: Greater Than 6 mcg/mL (SI: Greater Than 25.6 micromol/L)
Procainamide: Greater Than 10 mcg/mL (SI: Greater Than 42.5 micromol/L); N-Acetyl
Procainamide: Greater Than 40 mcg/mL (SI: Greater Than 170 micromol/L)
Quinidine: Greater Than 6 mcg/mL (SI: Greater Than 18.5 micromol/L)
Interfering factors
- Blood drawn in serum separator tubes (gel tubes).
- Drugs that may increase amiodarone levels include cimetidine.
- Drugs that may decrease amiodarone levels include cholestyramine and phenytoin.
- Drugs that may increase digoxin levels or increase risk of toxicity include amiodarone, amphotericin B, diclofenac, diltiazem, erythromycin, ibuprofen, indomethacin, nifedipine, nisoldipine, propafenone, propantheline, quinidine, spironolactone, tetracycline, tiapamil, troleandomycin, and verapamil.
- Drugs that may decrease digoxin levels include albuterol, aluminum hydroxide (antacids), carbamazepine, cholestyramine, colestipol, digoxin immune Fab, hydralazine, hydroxychloroquine, iron, kaolin-pectin, magnesium hydroxide, magnesium trisilicate, metoclopramide, neomycin, nitroprusside, paroxetine, phenytoin, rifabutin, sulfasalazine, and ticlopidine.
- Drugs that may increase disopyramide levels or increase risk of toxicity include amiodarone, atenolol, ritonavir, and troleandomycin.
- Drugs that may decrease disopyramide levels include phenobarbital, phenytoin, rifabutin, and rifampin.
- Drugs that may increase flecainide levels or increase risk of toxicity include amiodarone and cimetidine.
- Drugs that may decrease flecainide levels include carbamazepine, charcoal, phenobarbital, and phenytoin.
- Drugs that may increase lidocaine levels or increase risk of toxicity include beta blockers, cimetidine, metoprolol, nadolol, propranolol, and ritonavir.
- Drugs that may decrease lidocaine levels include phenytoin.
- Drugs that may increase procainamide levels or increase risk of toxicity include amiodarone, cimetidine, quinidine, ranitidine, and trimethoprim.
- Drugs that may increase quinidine levels or increase risk of toxicity include acetazolamide, amiodarone, cimetidine, itraconazole, mibefradil, nifedipine, nisoldipine, quinidine, ranitidine, thiazide diuretics, and verapamil.
- Drugs that may decrease quinidine levels include kaolin-pectin, ketoconazole, phenobarbital, phenytoin, rifabutin, and rifampin.
- Concomitant administration of amiodarone with other medications may result in toxic levels of the other medications related to the suppression of enzyme activity required to metabolize many other medications by amiodarone. It may also potentiate the anticoagulating effects of warfarin, resulting in increased PT values.
- Digitoxin cross-reacts with digoxin; results are falsely elevated if digoxin is measured when the patient is taking digitoxin.
- Digitalis-like immunoreactive substances are found in the serum of some patients who are not taking digoxin, causing false-positive results. Patients whose serum contains digitalis-like immunoreactive substances usually have a condition related to salt and fluid retention, such as renal failure, hepatic failure, low-renin hypertension, and pregnancy.
- Unexpectedly low digoxin levels may be found in patients with thyroid disease.
- Disopyramide may cause a decrease in glucose levels. It may also potentiate the anticoagulating effects of warfarin, resulting in increased PT values.
- Long-term administration of procainamide can cause false-positive antinuclear antibody results and development of a lupuslike syndrome in some patients.
- Quinidine may potentiate the effects of neuromuscular blocking medications and warfarin anticoagulants.
- Concomitant administration of quinidine and digoxin can rapidly raise digoxin to toxic levels. If both drugs are to be given together, the digoxin level should be measured before the first dose of quinidine and again in 4 to 6 days.
Nursing Implications and Procedure
Pretest
- Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
- Patient Teaching: Inform the patient this test can assist in monitoring for subtherapeutic, therapeutic, or toxic drug levels.
- Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
- Obtain a history of the patient’s cardiovascular system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
- These medications are metabolized and excreted by the kidneys and liver.
- Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus). Note the last time and dose of medication taken.
- Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
- Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
- Note that there are no food, fluid, or medication restrictions unless by medical direction.
Intratest
- Potential complications: N/A
- Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
- Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
- Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Consider recommended collection time in relation to the dosing schedule. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection, noting the last dose of medication taken. Perform a venipuncture.
- Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
- Promptly transport the specimen to the laboratory for processing and analysis.
Post-Test
- Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
- Nutritional Considerations: Include avoidance of alcohol consumption.
- Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Explain to the patient the importance of following the medication regimen and instructions regarding drug interactions. Instruct the patient to immediately report any unusual sensations (e.g., dizziness, changes in vision, loss of appetite, nausea, vomiting, diarrhea, weakness, or irregular heartbeat) to his or her HCP. Instruct the patient not to take medicine within 1 hr of food high in fiber (as the fiber may decrease absorption by binding some of the medication, reducing its bioavailability). Answer any questions or address any concerns voiced by the patient or family.
- Instruct the patient to be prepared to provide the pharmacist with a list of other medications he or she is already taking in the event that the requesting HCP prescribes a medication.
- Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Testing for aspirin responsiveness/resistance may be a consideration for patients, especially women, on low-dose aspirin therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
Related Monographs
- Related tests include ALT; albumin; ALP; apolipoproteins A, B, and E; AST; atrial natriuretic peptide; BNP; blood gases; BUN; CRP; calcium; calcium ionized; chest x-ray; cholesterol (total, HDL, and LDL); CBC platelet count; CK and isoenzymes; creatinine; ECG; glucose; glycated hemoglobin; homocysteine; ketones; LDH and isoenzymes; magnesium; myoglobin; potassium; triglycerides; and troponin.
- See the Cardiovascular System table at the end of the book for related tests by body system.
antiarrhythmic
1. preventing or alleviating cardiac arrhythmias.
2. an agent that prevents or alleviates cardiac arrhythmias.
antiarrhythmic drugs
include quinidine, procainamide, lidocaine, beta-adrenergic blockers such as propranolol, autonomic drugs including atropine and epinephrine, and digitalis.