Anticholinergics side effects

Anticholinergic side effects are categorized as peripheral or central. The most common peripheral side effects are dry mouth, decreased sweating, decreased bronchial secretions, blurred vision, difficulty with urination, constipation, and tachycardia. Bethanechol chloride, a cholinergic drug that does not cross the blood-brain barrier, may effectively treat these side effects at a dosage of 25-50 mg three times a day. 

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The Class I agents have many similar side effects and toxicities. The anticholinergic side effects include dry mouth, constipation, and urinary hesitancy and retention. Common gastrointestinal (GI) side effects include nausea, vomiting, diarrhea, and anorexia. Cardiovascular adverse effects are hypotension, tachycardia, arrhythmias, and myocardial depression, especially in patients with congestive heart failure. Common central nervous system (CNS) side effects are headache, dizziness, mental confusion, hallucinations, CNS stimulation, paraesthesias, and convulsions. 

The very slow onset of action and side effects which follow from the anticholinergic side effects characteristic of the tricyclic antidepressants has led to a continuing effort to find replacements from other structural classes which might thus be devoid of this defect. A series of alkoxy phenylpropylamines has been investigated extensively in this search for non-tricyclic antidepressants. The most recent analogue, tomoxetine (69), is accessible by the same route [15] used to prepare the earlier analogue, nisoxetine, in which methoxyl replaces the ortho methyl group. 

EPS Sedation Anticholinergic Side Effects Cardiovascular Side Effects Seizure Effects/ QTc Prolongation... 

Anticholinergic side effects include dry mouth, blurred vision, constipation, and urinary retention. More serious reactions include forgetfulness, sedation, depression, and anxiety. Patients with preexisting cognitive deficits and the elderly are at greater risk for central anticholinergic side effects. 

Treatment with a selective serotonin reuptake inhibitor is usually initiated in depressed patients with AD. Paroxetine causes more anticholinergic side effects than the other selective serotonin reuptake inhibitors. Ven-lafaxine may also be used. 

Although probably equally effective, the tricyclic antidepressants are usually avoided because of anticholinergic side effects. 

Anticholinergic side effects (e.g., dry mouth, blurred vision, constipation, urinary retention, tachycardia, memory impairment, and delirium) and sedation are more likely to occur with the tertiary amine TCAs than with the secondary amine TCAs. 

Ipratropium bromide has a slower onset of action than short-acting /J2-agonists (15 to 20 minutes vs. 5 minutes for albuterol). For this reason, it may be less suitable for as-needed use, but it is often prescribed in this manner. Ipratropium has a more prolonged bronchodilator effect than short-acting /l2-agonists. Its peak effect occurs in 1.5 to 2 hours and its duration is 4 to 6 hours. The recommended dose via MDI is two puffs four times a day with upward titration often to 24 puffs/day. It is also available as a solution for nebulization. The most frequent patient complaints are dry mouth, nausea, and, occasionally, metallic taste. Because it is poorly absorbed systemically, anticholinergic side effects are uncommon (e.g., blurred vision, urinary retention, nausea, and tachycardia). 

Trazodone (Desyrel). Trazodone was the first of the atypical antidepressants and was actually introduced prior to the SSRIs. It does not have the serious cardiac toxicity or anticholinergic side effects of the TCAs and was the most popular antidepressant until the arrival of the SSRIs. It is approved for the treatment of depression and is also commonly used in low doses to treat agitation in demented patients and insomnia. 

When treating insomnia without depression, doxepin and amitriptyline (both tricyclic antidepressants) can be administered in low doses (25-100 mg) at bedtime. These antidepressants, however, do have troublesome anticholinergic side effects (dry mouth, constipation, blurred vision, dizziness) and adverse effects on the heart, and they can be lethal if taken in overdose. Because of their effect on heart function, these antidepressants should be avoided in patients with heart problems and administered cautiously, if at all, to those who are already receiving one of any number of newer antidepressants that inhibit the metabolism of the TCAs. 

Antidepressants. Depression after TBl is routinely treated with antidepressant medicines. Although all antidepressants are potentially helpful, antidepressants prone to burdensome side effects, particularly sedative and anticholinergic side effects, should generally be avoided, as they are likely to be tolerated poorly by these patients. In addition, antidepressants that may increase the risk for seizure, such as many of the older tricyclic antidepressants (TCAs) and bupropion (Well-butrin), should be avoided because post-TBl patients as a rule are already more vulnerable to seizures. 

With the possible exception of maprotiline, which is chemically a modified TCA with all the side effects attributable to such a molecule, all of the newer non-tricyclic drugs have fewer anticholinergic effects and are less cardiotoxic than the older tricyclics. Lofepramine is an example of a modified tricyclic that, due to the absence of a free NH2 group in the side chain, is relatively devoid of anticholinergic side effects. Thus by slightly modifying the structure of the side chain it is possible to retain the efficacy while reducing the cardiotoxicity. 

All were double-blind controlled evaluations and established iprindole as at least as effective as imipramine, and one study [195] included an examination of the doctor-patient interaction as a factor in such work (a similar discussion was felt necessary, as noted above [179] in the evaluation of oxpertine). In only two [192, 194] of the above reports is it possible to estimate the frequency and severity of anticholinergic side effects, thou in the one case [192] the care taken in the experimental design and the number of patients observed leaves little doubt that the dry mouth, constipation, etc. characteristic of imipramine therapy is either greatly reduced or even absent during iprindole treatment. This point is confirmed in an extension of this team s work to include a 12 month toxicity study [197] which, in addition, failed to produce evidence of haemopoitic, hepatic, cardiac, ocular or renal damage. Similar results followed other work. 

The efficacy of fluoxetine in treating patients with moderate depression is comparable to the efficacy of tricyclic antidepressants. It is capable of elevating mood and removing feelings of fear and stress. It does not have a sedative effect. Fluoxetine is used in depression as well as in bulemic neuroses. Use of fluoxetine is preferred in cases when sedative, hypotensive, and anticholinergic side effects caused by other antidepressants are con-traindicative to patients. Prozac is a synonym for fluoxetine. 

In the event of increased anticholinergic side effects, plasma levels of disopyramide should be monitored and the dose of the drug adjusted accordingly. A reduction of the dose by one third, from the recommended 600 mg/day to 400 mg/day, would be... 

Renal/Hepatic function impairment Use with caution and in reduced doses in patients with hepatic impairment metabolism may be impaired, leading to drug accumulation. Use with caution in patients with significantly impaired renal function. Elderly Be cautious in dose selection for an elderly patient, usually starting at the low end of the dosing range. Elderly patients may be sensitive to the anticholinergic side effects of TCAs. 

Atropine A subtherapeutic dose of atropine has been added to difenoxin to discourage deliberate overdosage. A recommended dose is not likely to cause prominent anticholinergic side effects, but avoid in patients in whom anticholinergic drugs are P.833... 

Anticholinergic side-effects are dry mouth, urinary retention and constipation. Confusion and drowsiness occur especially in the elderly and because of their poor risk-benefit ratio old age is a relative but serious contraindication for the use of these agents. 

Meperidine Demerol) is a phenylpiperidine derivative of morphine that was developed in the late 1930s as a potential antichohnergic agent. It has some anticholinergic side effects that lead to tachycardia, blurred vision, and dry mouth. Meperidine is approximately one-fifth as potent as morphine and is absorbed only half as well when administered oraUy as parenteraUy. It has a rapid onset and short duration of action (2 hours), that is, approximately one-fourth that of morphine. 

Although atropine and related compounds possess bronchodilator activity, their use is associated with the typical spectrum of anticholinergic side effects (see Chapter 13), and they are no longer used in the treatment of asthma. To improve the clinical utility of anticholinergics, quaternary amine derivatives of atropine were developed. By virtue of their positive charge, these drugs are absorbed poorly across mucosal surfaces and thus produce fewer side effects than atropine, especially when given by inhalation. 

Other Orthostatic hypotension, cardiac conduction disturbances, anticholinergic side effects... 

Geriatric Considerations - Summary Glycopyrrolate does not cross the blood-brain barrier so is less likely to cause the central effects seen with anticholinergics such as atropine. Other anticholinergic side effects such as blurred vision, dry mouth, urinary retention, and constipation do occur and can limit the usefulness of this drug in the older adult. 

Reported anticholinergic side effects not clinically or significantly different from... 

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