Agitation anticholinergic drugs

Elderly Elderly patients may react with excitement, agitation, drowsiness, and other untoward manifestations to even small doses of anticholinergic drugs. 

Agitated Increased Dilated Hallucinations, hypertension and tachycardia, dry skin, mucous membranes, flushed skin with fever Anticholinergic drugs... 

Rebound psychosis or delirium or both have been reported after withdrawal of clozapine (207-212). Clozapine withdrawal has also been associated with nausea, vomiting, diarrhea, headache, restlessness, agitation, and sweating (213,214), which occur as the result of cholinergic rebound and which may respond to anticholinergic drugs (215), and with dystonias and dyskinesias. Delirium and the return of dyskinetic movements can occur within days after clozapine withdrawal. 

A 39-year-old man who was a recreational user of alcohol and cocaine presented with agitation, hallucinations, and delirium. He had a dry flushed skin, tachycardia, dilated, minimally reactive pupils, urinary retention, and absent bowel sounds. He was treated with intravenous fluids and a sedative. There were cocaine metabolites in the urine. Reanalysis of a urine sample by thin layer chromatography confirmed the presence of the anticholinergic drug atropine. 

This case exemplifies the difficulty in identif)dng anticholinergic drugs such as atropine, and unfortunately the finding of dilated pupils did not raise the suspicion of mixed drug toxicity. The use of naloxone uncovered florid agitation due to anticholinergic drug toxicity. 

Insomnia, hypotension, agitation, headache, and rhinitis are the most common side effects of risperidone. These tend to lessen with time. Overall, the drug tends to be well tolerated. Average weight gain associated with risperidone after 10 weeks of treatment is 2.10 kg (AUison et al. 1999). Risperidone does not have significant anticholinergic side effects. Hyperprolactinemia is common. 

The four drugs were administered by psychiatrists blinded to treatment group assignment of patients. The 14-week study consisted of an 8-week dose escalation and fixed dose and a 6-week variable-dose period. The mean dose levels (mg/day) of the four compounds after the first 8 weeks were 452 for clozapine. 20.2 for olanzapine. 8.3 for risperidone and 19.6 for haloperidol. Patients on haloperidol received prophylactic anticholinergic medication to prevent extrapyramidal symptoms, and a few other drugs were permitted to treat agitation and insomnia. 

MAO Inhibitors. In contrast to the tricyclics, MAO inhibitors tend to produce CNS excitation, which can result in restlessness, irritability, agitation, and sleep loss. These drugs also produce some central and peripheral anticholinergic effects (e.g., tremor, confusion, dry mouth, urinary retention), but these effects tend to occur in a lesser extent than with the tricyclics (see Table 7-3). Because of the systemic MAO inhibition, excess activity at peripheral sympathetic adrenergic terminals may cause a profound increase in blood pressure, leading to a hypertensive crisis. This situation is exacerbated if other drugs that increase sympathetic nervous activity are being taken... 

The classic anticholinergic syndrome is remembered as "red as a beet" (skin flushed), "hot as a hare" (hyperthermia), "dry as a bone" (dry mucous membranes, no sweating), "blind as a bat" (blurred vision), and "mad as a hatter" (confusion, delirium). Patients usually have sinus tachycardia, and the pupils are usually dilated (see Chapter 8 Cholinoceptor-Blocking Drugs). There may be agitated delirium or coma. Muscle twitching is common, but seizures are unusual unless the patient has ingested an antihistamine or a tricyclic antidepressant. Urinary retention is common, especially in older men. 

Drug treatment of anticholinergic delirium is typically not recommended, although benzodiazepines can be used to treat severe agitation. Neuroleptics, with their anticholinergic properties, are relatively contraindicated. 

The CNS manifestations of tricyclic antidepressant overdose may vary from mild agitation or drowsiness to delirium, coma, respiratory depression, or seizures. These manifestations are thought to result in part from central anticholinergic and antfliistaminic actions of these drugs. 

---