What is the primary goal for prescribing an anticholinergic agent for a preoperative client?

Drug information provided by: IBM Micromedex

US Brand Name

1. Akineton
2. Artane
3. Bentyl
4. Cantil
5. Cogentin
6. Colidrops Pediatric
7. Cystospaz
8. Detrol
9. Ditropan
10. Ed-Spaz
11. Enablex
12. HyoMax
13. HyoMax-DT
14. HyoMax-FT
15. HyoMax-SR
16. Hyosyne
17. IB-Stat
18. Levsinex
19. Neosol
20. Norflex
21. Nulev
22. Oscimin
23. Oscimin-SR
24. Oxytrol
25. Pamine
26. Pro-Banthine
27. Pro-Hyo
28. Robinul
29. Sanctura
30. Scopodex
31. Spacol TS
32. Spasdel
33. Symax
34. Symax Duotab
35. Symmetrel
36. Toviaz
37. Transderm Scop
38. Urispas
39. Vesicare

Canadian Brand Name

1. Buscopan
2. Levsin
3. Pms-Trihexyphenidyl
4. Transderm-V

Descriptions

The anticholinergics and antispasmodics are a group of medicines that include the natural belladonna alkaloids (atropine, belladonna, hyoscyamine, and scopolamine) and related products.

The anticholinergics and antispasmodics are used to relieve cramps or spasms of the stomach, intestines, and bladder. Some are used together with antacids or other medicines in the treatment of peptic ulcers. Others are used to prevent nausea, vomiting, and motion sickness.

Anticholinergics and antispasmodics are also used in certain surgical and emergency procedures. In surgery, some are given by injection before anesthesia to help relax you and to decrease secretions, such as saliva. During anesthesia and surgery, atropine, glycopyrrolate, hyoscyamine, and scopolamine are used to help keep the heartbeat normal. Scopolamine is also used to prevent nausea and vomiting after anesthesia and surgery. Atropine is also given by injection to help relax the stomach and intestines for certain types of procedures.

Anticholinergics are used to treat poisoning caused by medicines such as neostigmine and physostigmine, certain types of mushrooms, and “nerve” gases or organic phosphorous pesticides (eg, demeton [Systox®], diazinon, malathion, parathion, and ronnel [Trolene®]). Anticholinergics can be used for painful menstruation, runny nose, and to prevent urination during sleep.

The anticholinergics and antispasmodics are available only with your doctor's prescription.

This product is available in the following dosage forms:

• Tablet, Extended Release
• Capsule, Liquid Filled
• Tablet
• Solution
• Syrup
• Capsule
• Capsule, Extended Release
• Elixir
• Tablet, Disintegrating
• Suspension
• Patch, Extended Release
• Gel/Jelly
• Tablet, Chewable
• Liquid

Portions of this document last updated: Oct. 01, 2022

Copyright © 2022 IBM Watson Health. All rights reserved. Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.

.

Ischemic heart disease

Patients with known coronary artery disease undergoing surgery should be monitored for evidence of myocardial ischemia and provided therapy to prevent and treat ischemia in the perioperative period.

Monitoring techniques during the perioperative period include surveillance of electrocardiographic ST-changes, echocardiographic assessment of the regional and global wall motion, and invasive measurement of pulmonary arterial and capillary wedge pressures. If ischemia is detected, medication should be titrated to specific endpoints of heart rate and blood pressure or until the ischemia resolves.

Beta-blockers provide the single best therapy for prevention of ischemia during the perioperative period. Postoperative myocardial infarction (MI) and angina have a peak incidence during the first 3 postoperative days but may occur for up to 5 days. Recent studies suggest that postoperative cardiac events may be decreased by use of perioperative beta-blocker regimens. In an excellent randomized, double-blind, placebo-controlled trial, Mangano et al showed that for patients who have or are at high risk for coronary artery disease and undergo noncardiac surgery, treatment with atenolol during hospitalization can reduce mortality and the incidence of cardiac complications for at least 2 years after the surgery. [2] Most hospitals now have clinical practice guidelines regarding perioperative beta-blockers.

Ischemia frequently presents atypically, with chest pain occurring only 50% of the time. In the event of possible signs of ischemia, following up the ECG with serial enzyme measurements, echocardiography, or nuclear perfusion studies may be required. If no evidence of perioperative ischemia or infarction is present, then using a simple 12-lead ECG immediately after surgery and for the first 2 postoperative days is sufficient to evaluate any change from baseline. The following chart indicates the perioperative drug management of patients with coronary artery disease.

Table 1. Outline of Perioperative Drug Management of Patients With Coronary Artery Disease (Open Table in a new window)

Hypertension

Hypertension is a risk factor for coronary artery disease. Patients with elevated blood pressure seem more likely to experience significant fluctuations in intraoperative blood pressure and associated MI. Adequate blood pressure control is essential prior to elective surgeries because this reduces perioperative ischemia and subsequent cardiac morbidity. [3]

Continue antihypertensive medications throughout the perioperative period, with a change of formulation or substitution if needed. Abrupt withdrawal of beta-blocking agents may adversely affect the heart rate and blood pressure and may precipitate MI.

Administer all antihypertensive medications (with a sip of water) except diuretics and ACE inhibitors until the day of surgery. Diuretics should not be administered on the day of surgery because of the potential adverse interaction of diuretic-induced volume depletion, potassium derangement, and the use of anesthetic agents. The renin-angiotensin-aldosterone system (RAAS) is involved in maintaining normal blood pressure during anesthesia. Hemodynamic instability, including refractory hypotension, has been described in RAAS-blocked patients. Therefore, ACE inhibitors should be discontinued the day before surgery. [4, 5, 6]

Appropriate perioperative management of pain, anxiety, hypoxia, and hypothermia with rewarming are key to maintaining normotension. Patients with a history of preoperative hypertension are predisposed to postoperative hypertension and to intraoperative blood pressure lability. Restarting the patient's oral medications and minimizing oral and intravenous sodium when possible are important therapies.

For those patients unable to take oral medications who require treatment, parenteral alternatives must be used. Intravenous beta-blockers, including propranolol, atenolol, and metoprolol, are particularly attractive because of their previously discussed antiischemic benefits in the perioperative period. Other alternatives are intravenous enalapril, verapamil, or diltiazem and the transdermal clonidine patch. For more serious hypertension, labetalol, nitroglycerin, and nitroprusside are appropriate. In general, avoidance of parenteral hydralazine is warranted in patients with ischemic heart disease because the reflex tachycardia produced may lead to ischemia. Use of sublingual nifedipine is associated with strokes, MI, and death. Also, keep in mind that the clonidine patch is not fully active until 48 hours after placement.

For many patients with only mild postoperative elevations of blood pressure, withholding parenteral antihypertensives until they can take oral medications, while limiting sodium and aggressively controlling pain and anxiety, is appropriate. Clonidine and similar drugs may result in severe rebound hypertension when discontinued abruptly before surgery. Administer with a sip of water on the day of surgery, and continue with transdermal administration (therapeutic systemic levels of transdermal clonidine are not reached for 48 h) or substitute with intravenous methyldopa, nitroprusside, or phentolamine.

Although not commonly used, methyldopa may be discontinued in the perioperative period if needed. Reserpine and prazosin must be given until the day before surgery, then resumed postoperatively. Hydralazine is typically used in combination with beta-blockers. Observe caution with intravenous formulations because the dose required is less than the oral dose.

Table 2. Perioperative Drug Management for Patients With Hypertension (Open Table in a new window)

Congestive heart failure, valvular heart disease, arrhythmia, and conduction system disease

Patients with congestive heart failure (CHF) need stabilization with diuretics, digoxin, ACE inhibitors, and nitroglycerides prior to surgery. Preoperative CHF is the strongest predictor of postoperative pulmonary edema.

Hemodynamic monitoring with a pulmonary artery catheter is recommended for patients with severe CHF requiring emergency surgery. This should extend at least 48 hours postoperatively to guide fluid management. Loss of cardiac pump function leading to CHF significantly increases perioperative risk.

Although postoperative CHF occurs in only approximately 1-6% of patients, the associated mortality rate is 15-20%. During surgery, volume changes, other intraoperative stressors, and the myocardial depressant actions of anesthetic agents can lead to a significant decrease in cardiac output.

Following surgery, most sequestered fluid is mobilized within the first 48 hours, placing an increased load on the heart. This is also a period of greatly increased metabolic and neurohumoral stress. Most postoperative CHF occurs within 1 hour following surgery, and, in 50% of these cases, inappropriate fluid administration is a major factor.

Heart valve prostheses

For those patients with heart valve prostheses, anticoagulant management is an important component of perioperative care. [7]

For major surgeries, substituting warfarin with heparin is recommended to maintain anticoagulation until the time of surgery. The short half-life of heparin allows the patient to safely undergo surgery within a few hours after discontinuation. Heparin should be discontinued 6 hours prior to surgery and then restarted 12-24 hours after surgery, when postoperative hemorrhage is no longer a threat. Monitor heparin by maintaining an activated partial thromboplastin time (aPTT) of 1.5- to 2-times normal. For patients on warfarin, checking the prothrombin time 1 day prior to the day of the operation and administering vitamin K (1-3 mg is generally sufficient), if necessary, is recommended.

Therapeutic anticoagulation is typically not reestablished for several days after warfarin is initiated; therefore, the patient should again receive heparin in the postoperative period until oral anticoagulation is fully therapeutic. Start warfarin and adjust to an International Normalized Ratio (INR) based on the underlying reason for the long-term anticoagulation.

For minor surgery (eg, cataract removal, most dental surgeries), Coumadin does not need to be discontinued, although many surgeons still request it.

When substituting warfarin with heparin, low molecular weight heparin (LMWH) generally can be used. Widespread anecdotal experience among cardiologists and internists suggests that Lovenox in a dose of 1 mg/kg bid can be used safely instead of unfractionated heparin, but double-blind studies have not been conducted. The exception to this is prosthetic valves requiring an INR of 3-3.5. Because of the lack of experience with LMWH in this setting, conventional heparin should still be used.

When using LMWH, the last dose should be 12 hours before surgery. However, if spinal anesthesia is anticipated, the last dose should be 24 hours before surgery.

For patients taking warfarin for atrial fibrillation, warfarin can be stopped safely without interim use of heparin. The exception to this is the high-risk patient with atrial fibrillation (eg, history of prior embolization, known atrial thrombus).

Arrhythmia

Treat life-threatening arrhythmia in the perioperative period.

Continue digoxin for control of atrial fibrillation and supraventricular tachycardia in the perioperative period. Bioavailabilities differ with oral and parenteral preparations; therefore, carefully administer appropriate dosages.

Because a risk of digitalis toxicity and perioperative arrhythmia exists, some clinicians prefer to withhold the medication 12 hours before surgery.

Patients on quinidine should receive their dose on the night before surgery. Intravenous lidocaine may be used for ventricular arrhythmia, and intravenous propranolol or verapamil can be used for supraventricular arrhythmias. Quinidine is restarted as soon as patient is on oral sips.

Patients on procainamide, similar to those on quinidine, should receive their dose on the night before surgery. To control arrhythmia in the intraoperative period, intravenous procainamide or lidocaine may be used. Poorly tolerated supraventricular arrhythmia may be treated with propranolol and verapamil.

Disopyramide has a negative inotropic effect with adverse anticholinergic effects of urinary retention and constipation; therefore, it is discontinued on the night prior to surgery and substituted with intravenous lidocaine in the perioperative period.

Tocainide is an oral agent similar to lidocaine and may be used for the treatment of ventricular arrhythmia. Administer the night before surgery, and use intravenous lidocaine until the patient resumes oral tocainide.

Discontinue amiodarone, used in life-threatening arrhythmia, on the night before surgery. It has a long half-life (30-60 d); therefore, it can be restarted safely after the patient is on oral feedings. If arrhythmia develops in the perioperative period, the intravenous preparation can be used in conjunction with conventional intravenous drugs (eg, procainamide, lidocaine).

A rare postoperative reaction in patients on amiodarone is acute respiratory distress syndrome, but the exact inciting anesthetic drug or intraoperative event is not understood.

Verapamil (for arrhythmia) is given with a sip of water on the morning of surgery, and an intravenous formulation can be used to cover the perioperative period.

To summarize, those patients on long-term therapy for supraventricular tachycardia should receive their usual medication in the perioperative period. Supplemental rate control can be achieved with calcium channel blockers, beta-blockers, or cautious use of digoxin. Treatment of sustained ventricular arrhythmia with oral medication should occur until the day of surgery, when substitution with intravenous procainamide or lidocaine is used.

Drugs in hypotension

Hypotension can occur at any time during surgery as a result of blood or fluid loss and from the effects of vasoactive anesthetic drugs. Medications used to treat coexisting cardiovascular disorders may also exacerbate hypotension.

Phenylephrine is a selective alpha-1 adrenergic agent that causes peripheral vasoconstriction. It is useful in the treatment of hypotension associated with spinal anesthesia, as well as in patients with coronary artery disease or aortic stenosis to increase coronary perfusion pressure. It can be administered in bolus doses of 40-100 mcg through a peripheral intravenous line or an infusion of 10-20 mcg/min. It has a rapid onset of action and short duration of action (5-10 min).

Serum calcium levels are decreased with the administration of heparin and albumin or after a transfusion of blood preserved with citrate. Low serum concentrations of ionized calcium are associated with myocardial depression and decreased peripheral vascular resistance. Calcium ions increase myocardial contractility and have a variable effect on systemic vascular resistance. However, calcium is best used in the treatment of hyperkalemia and hypotension in patients who are hypocalcemic and are receiving calcium channel blockers. Calcium should be administered as a slow intravenous bolus of 0.5-1 g.

Dopamine is used in the treatment of cardiogenic shock, CHF, and following cardiac surgery. It has 3 different actions at 3 pharmacologic doses. When administering in the range of 0.5-2 mcg/kg/min, it increases renal blood flow and urine output via DA1 receptors, which are postsynaptic and act on renal, mesenteric, splenic, and coronary vascular smooth muscle to mediate vasodilation through stimulation of adenylate cyclase and increased production of cAMP. [8] At 3-10 mcg/kg/min, it increases inotropy and chronotropy, augmenting cardiac output. Finally, at more than 10 mcg/kg/min, it increases total peripheral resistance.

Dobutamine is a β-adrenergic receptor agonist with minimal α-adrenergic receptor agonist activity. It is a positive chronotropic and inotropic agent with pulmonary and systemic vasodilatory effect. It decreases total peripheral resistance and increases cardiac output, without the tendency to cause tachycardia that may be evident with dopamine. It is useful in low cardiac output states when an increase in left ventricular end-diastolic volume and pulmonary vascular resistance is not desirable. It is administered as an infusion of 5-15 mcg/kg/min.

Epinephrine is a naturally occurring catecholamine found in the adrenal medulla. It is an α- and β-adrenergic receptor agonist (β-adrenergic receptor predominance at lower doses) that increases cardiac contractility and the heart rate, accentuates systolic and mean blood pressures, and serves as an effective bronchodilator. It should be used as an infusion, starting at 1-4 mcg/min, and then titrated to cardiac output and blood pressure.

Norepinephrine causes vasoconstriction and has positive inotropic action without increasing the heart rate. It has primarily α-, with minimal β2 -receptor, activity. It should be used as an infusion, starting at 1-4 mcg/min and titrated to blood pressure.

Milrinone is a noncatecholamine inotropic agent (phosphodiesterase inhibitor) with hemodynamic properties similar to those of dobutamine. Inhibition of myocardial type III phosphodiesterase leads to an increase in myocardial cAMP, which increases the influx of intracellular Ca2+ and has a positive inotropic effect independent of β-adrenergic receptor stimulation. It increases cardiac inotropy and slightly decreases total peripheral resistance, thereby improving cardiac output. It causes pulmonary and coronary vasodilation.

(See also the pill identifier tool.)

Why are anticholinergics used before surgery?

Why are anticholinergic drugs used with anesthesia?

What are indications for anticholinergics?