Drugs with Anticholinergic Effects

Baldwin DS and Polkinghorn C (2005) Evidence-based pharmacotherapy of Generalized Anxiety Disorder. Int J Neuropsychopharmacol 8(2) 293-302 Ballard C, Hanney ML, Theodoulou M et al. (2009) The dementia antipsychotic withdrawal trial (DART-AD) long-term follow-up of a randomised placebo-controlled trial. The Lancet Neurology DOI 10.1016/S 1474-4422(08)70295-3 

Ballard C, Lana MM, Theodoulou M et al. (2008) A randomised, blinded, placebo-controlled trial in dementia patients continuing or stopping antipsychotics (the DART-AD trial). PLoS Med 5(4) e76 

Bogunovic Ol and Greenfield SF (2004) Practical geriatrics Use of benzodiazepines among elderly patients. Psychiatr Serv 55(3) 233-235 

Brodaty H, Ames D, Snowdon 1 et al. (2003) A randomized placebo-controlled trial of risperidone for the treatment of aggression, agitation, and psychosis of dementia. 1 Clin Psychiatry 64(2) 134-143 

Carlsten A, Waern M, Holmgren P et al. (2003) The role of benzodiazepines in elderly suicides. Scand 1 Public Health 31(3) 224-248 

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There is an increased central nervous system (CNS) depressant effect when the skeletal muscle relaxants are administered with other CNS depressants, such as alcohol, antihistamines, opiates, and sedatives. There is an additive anticholinergic effect when cyclobenzaprine is administered with other drugs with anticholinergic effects (eg, antihistamines, antidepressants, atropine, haloperidol). See Chapter 30 for information on diazepam. 

Drugs with anticholinergic effects may cause delirium but also tachycardia, urinary retention, constipation, dry mouth and blurred vision... 

It is also very important, if possible, to discontinue or lower the doses of drugs with anticholinergic effects antihistamines, antipsychotics, antidepressants, uro-logic spasmolytics, anti-arrhythmics, drugs for Parkinson s disease and more. Prophylactic treatment against Candida infection, bacteria and caries can also be useful (Mouly et al. 2007). 

Constipation may be caused by slow intestinal transition, pelvic floor dysfunction, bowel dysfunction like irritable Bowel syndrome and tumours, but can also be secondary to other diseases and life conditions. Many medicines cause constipation, for example opiates, calcium channel blockers and drugs with anticholinergic effects, e.g. antidepressants. 

The anticholinergic effects of cannabis (127) may result in interactions with other drugs with anticholinergic effects, such as some antidysrhythmic drugs. 

Banshchikov, V.M. and Stoliarov, G.V. 1966 Psychotomimetic drugs with anticholinergic effects. (Russian). Zh. nevropatol. Pslkhlatr. 66 464-468. 

The effect of acetylcholinesterase inhibitors can be reduced by drugs with anticholinergic effects, such as antihistamines or neuroleptic drugs (12). 

Drugs with anticholinergic effects (including pheno-thiazines, tricyclic antidepressants, quinidine, and diso-pyramide) will have their effects increased by antihistamines. 

Certain drugs with anticholinergic effects are used for the symptomatic treatment of Parkinson s disease (paralysis agitans) and related syndromes of the extrapyramidal tracts. (Of the presently available drugs, none is useful in all cases of Parkinsonism.) Despite claims of superiority for newly introduced synthetic agents, none possesses outstanding efficacy and freedom from adverse side effects when compared clinically with atropine and scopolamine (241). 

Drugs with anticholinergic effects are widely used in elderly people. In patients with dementia aged 65 years and over, the 2004... 

Ehrt U, Broich K, Larsen JP, Ballard C, Aarsland D. Use of drugs with anticholinergic effect and impact on cognition in Parkinson s disease a cohort study. J Neurol Neurosurg Psychiatry 2010 81(2) 160-5. 

Anticholinergics are associated with many side effects including mood change, confusion, hallucinations, drowsiness, and cardiac irregularity.13,39 In addition, blurred vision, dryness of the mouth, nausea/ vomiting, constipation, and urinary retention are fairly common. Antihistamine drugs with anticholinergic properties are also used occasionally (Table 10-2). 

May increase anticholinergic effects of procyclidine and other drugs with anticholinergic properties... 

Pirenzepine is an anticholinergic drug with selective effects on muscarinic Mi receptors. It therefore inhibits gastric acid secretion in the stomach. When it was introduced it was claimed that in the doses necessary to affect gastric acid secretion it would be almost entirely free of other muscarinic (atropine-like) effects. However, although muscarinic adverse effects, such as dry mouth and difficulty in accommodation, are less common with pirenzepine than with atropine, they can still occur in about half the patients who take the drug (1). Cardiac conduction effects resulting in sinus tachycardia, atrial fibrillation, and nodal tachycardia can also occur. 

Dibenzoxepin Tricyclics (Doxepin). Doxepin, the only drug in this class, is marketed as a tricyclic antidepressant. However, it is also a remarkably potent H, antagonist. It can cause drowsiness and is associated with anticholinergic effects. Doxepin is much better tolerated by patients who have depression than by those who do not. In nondepressed patients, sometimes even very small doses, e.g., 20 mg, may be poorly tolerated because of disorientation and confusion. 

Anticholinergics/ Antihistamines Diphenhydramine, dimenhydrinate and meclizine are antihistamines with anticholinergic effects. Anticholinergic drugs reduce motion sickness as well as emesis. 

Amantadine is used cautiously in patients with seizure disorders, psychiatric problems, renal impairment, and cardiac disease. Amantadine is a Pregnancy Category B drug and is used cautiously during pregnancy and lactation. Concurrent use of antihistamines, phenothiazines, tricyclic antidepressants, disopyramide, and quinidine may increase the anticholinergic effects (dry mouth, blurred vision, constipation) of amantadine... 

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