Anticholinergic medication

Medications aimed at decreasing pancreatic enzyme release (e.g., somatostatin), nasogastric suction, and anticholinergic medications have all failed to show benefit in the treatment of acute pancreatitis. 

Levodopa, a dopamine precursor, is the most effective agent for PD. Patients experience a 40% to 50% improvement in motor function. It is absorbed in the small intestine and peaks in the plasma in 30 to 120 minutes. A stomach with excess acid, food, or anticholinergic medications will delay gastric emptying time and decrease the amount of levodopa absorbed. Antacids decrease stomach acidity and improve levodopa absorption. Levodopa requires active transport by a large, neutral amino acid transporter protein from the small intestine into the plasma and from the plasma across the blood-brain barrier into the brain (Fig. 29-2). Levodopa competes with other amino acids, such as those contained in food, for this transport mechanism. Thus, in advanced disease, adjusting the timing of protein-rich meals in relationship to levodopa doses may be helpful. Levodopa also binds to iron supplements and administration of these should be spaced by at least 2 hours from the levodopa dose.1,8,16,25... 

Pharmacotherapy. The currently available treatments for PD are symptomatic, and do not alter the course of the disease. The earliest treatment that is still in limited use today, is with the anticholinergic medications, such as trihexiphenidyl or benzotropine. These drugs are useful, particularly for tremor. However, their use is often prob-lematic because of unpleasant side-effects, such as memory disturbances, blurred vision, sedation, dry mouth, or urinary retention, particularly in older patients. 

Following abrupt withdrawal of anticholinergic medications cholinergic rebound can cause a relapse... 

Prostatic hypertrophy, infection, cancer Improperly placed bladder catheter Anticholinergic medication Cancer with abdominal mass Retroperitoneal fibrosis Nephrolithiasis Nephrolithiasis Oxalate Indinavir Sulfonamides Acyclovir Uric acid... 

Ness J, Floth A, Barnett MJ et al. (2006) Anticholinergic medications in community-dwelling older veterans prevalence of anticholinergic symptoms, symptom burden, and adverse drug events. Am J Geriatr Pharmacother 4(1) 42-51... 

We prefer low doses of atypical antipsychotics as a first-line treatment. In this way, the threat of extrapyramidal symptoms is largely avoided without having to use a second anticholinergic medication to offset antipsychotic side effects. Risperidone 0.25-0.5mg/day, olanzapine 2.5mg/day, quetiapine 25mg/day, ziprasidone 20mg/day, or aripiprazole 2.5-5mg/day are reasonable starting doses. The typically higher doses used to treat schizophrenia are usually not necessary. 

Take a Second Medication as a Countermeasure. Sometimes despite problematic side effects, it may be necessary that a patient remain on a particular medication. This is a good time to address the risk-benefit approach to side effects. The best comparison is not the side effects associated with a particular medication compared to the lack of side effects without taking the pill it is the side effects of treatment versus the consequences of the untreated disease state. So what if a patient is on a medication that works for them when previous trials have proved unsuccessful, but there is the presence of one or more uncomfortable side effects This does not necessarily leave you powerless to deal with the side effects. One approach is to use a second medication to counteract the side effect of the first medication. One common example of this approach is using anticholinergic medications such as diphenhydramine (Benadryl) or benztropine (Cogentin) to counteract certain side... 

Anticholinergic medications can produce a variety of side effects. They can cause dry mouth and dry skin. Dry mouth is not only a nuisance but can lead to rapid tooth decay as well. Anticholinergic medications can also cause blurred vision and... 

Whenever possible, anticholinergic medications should be avoided or kept to a minimum. This is an important consideration because a wide variety of medications, psychiatric and otherwise, possess some acetylcholine-blocking properties. When a patient is using several medications, it is important to review the relative anticholinergic contribution of each medication. Taking one mildly anticholinergic medication may not be a problem, but taking three or four can have additive effects that do become problematic. 

Anticholinergic agents There is some potential for an additive interaction with concomitantly used anticholinergic medications. 

On to the activation-synthesis hypothesis, according to which dreams are caused by a cholinergically activated forebrain, anticholinergic medications and damage to cholinergic forebrain structures should produce decreased fre-... 

Anticholinergic side effects result from antagonism of muscarinic receptors. The most common anticholinergic side effects are dry mouth, constipation, urinary retention, blurred vision, and tachycardia. In predisposed patients, such as elderly persons, anticholinergic medications may cause cognitive impairment and confusion. Because the tertiary amines and protriptyline have a particularly high affinity for muscarinic receptors, these medications are more likely than others to have anticholinergic side effects. 

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. 

Preclinical studies of ziprasidone indicate that it also has a low propensity to induce EPS, which was confirmed in subsequent phase II and III studies. Furthermore, the motor symptoms evoked by ziprasidone were seldom sufficiently troublesome to warrant anticholinergic medication. In one phase III trial, not more than 25% of patients receiving 160 mg/day were prescribed an anticholinergic at any time during the 6-week treatment period. These results indicate that therapeutic doses of ziprasidone not only induce a low incidence of acute EPS, but when they occur, they are often mild and do not require antiparkinsonian medication (137). 

FIGURE 11—54. Cognitive symptom pharmacy. Atypical antipsychotic dmgs (SDA) may improve cognitive functions in both schizophrenic and Alzheimer patients (first-line treatment). They may boost the actions of cholinesterase inhibitors (ChEIs) in Alzheimer s disease. It may also be useful to discontinue any anticholinergic medication that you can, a welcome bonus when switching from conventional antipsychotics to atypical antipsychotics (decreased A Ch). 

Tandon R, Mann NA, Eisner WH, Coppard N. 1990. Effect of anticholinergic medication on positive and negative symptoms in medication-free schizophrenic patients. Psychiatry... 

Clinicians often encounter patients with dementia and urge incontinence who might benefit from both anticholinergic medication and a cholinesterase inhibitor (68), a paradoxical combination. 

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