Anticholinergic agent interaction

Drugs that interact with oxybutynin include atenolol, digoxin, haloperidol, phenothiazines, amantadine, and anticholinergic agents. 

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

Drugs that may interact with halopehdol include anticholinergic agents, azole antifungal agents, carbamazepine, lithium, rifamycins, and fluoxetine. 

B. Anticholinergic agents, such as procainamide and disopyramide, are relatively contraindicated in patients with glaucoma. Procainamide is hypotensive rather than hypertensive. The local anesthetic activity of procainamide would have no adverse interaction with the diabetes mellitus. 

Cydobenzaprine (Flexeril) [Skeletal Muscle Relaxant/ANS Agent] Uses Relief of muscle spasm Action Centrally acting skeletal muscle relaxant reduces tonic somatic motor activity Dose 5-10 mg PO bid-qid (2-3 wk max) Caution [B, ] Shares the toxic potential of the TCAs urinary hesitancy, NAG Contra Do not use concomitantly or w/in 14 d of MAOIs hyperthyroidism heart failure arrhythmias Disp Tabs SE Sedation anticholinergic effects Interactions T Effects of CNS depression W/ CNS depressants, TCAs, barbiturates, EtOH T risk of HTN convulsions W/ MAOIs EMS Use caution w/ other CNS depressants concurrent EtOH use can T CNS depression OD May cause N/V,... 

Inhibitors of CYP450 2D6 and CYP450 3A4 may inhibit donepezil metabolism and increase its plasma levels Inducers of CYP450 2D6 and CYP450 3A4 may increase clearance of donepezil and decrease its plasma levels Donepezil may interact with anticholinergic agents and the combination may decrease the efficacy of both... 

Galantamine may interact with anticholinergic agents and the combination may decrease the efficacy of both... 

Drug interactions Additive CNS depressant effects may occur when antihistamines are administered concomitantly with other CNS depressants, including barbiturates, benzodiazepines, alcohol, and other sedatives. Additive anticholinergic effect also may occur when used in combination with other anticholinergic agents. 

Clinically important, potentially hazardous interactions with acarbose, acetaminophen, alcohol, anticholinergic agents, atropine, miglitol... 

Flushed red skin may be caused by carbon monoxide poisoning, boric acid intoxication, chemical burns from corrosives or hydrocarbons, or anticholinergic agents. It may also result from vasodilation (eg, phenothiazines or disulfiram-ethanol interaction). 

Drugs that may interact with anticholinergic antiparkinson agents include... 

Tricyclic antidepressants are notorious for their risk to be involved in drug-drug interactions. Additive anticholinergic effects can be expected in combination with antihistamines, antipsychotics and anticholinergic-type anti-Parkinson agents. Hepatic enzyme-inducing agents increase their hepatic metabolism while enzyme inhibitors may potentiate the effects of tricyclics. Concomitant use with monoamine oxidase inhibitors will produce hypertension, hyperpyrexia and convulsions. 

Common pharmacodynamic interactions involve the additive anticholinergic or antidopaminergic effects of antipsychotics. Thus, concomitantly administered antiparkinsonian agents (e.g., benztropine) may increase the chances of toxicity (e.g., delirium) while dopamimetic agents (e.g., levodopa) may counteract the antipsychotic or neurotoxic effects of these agents. 

Elevations of TCA levels may occur when combined with CYP2D6 inhibitors or from constitutional factors. About 7% of the Caucasian population in the USA has a CYP2D6 polymorphism that is associated with slow metabolism of TCAs and other 2D6 substrates. Combination of a known CYP2D6 inhibitor and a TCA in a patient who is a slow metabolizer may result in additive effects. Such an interaction has been implicated, though rarely, in cases of TCA toxicity. There may also be additive TCA effects such as anticholinergic or antihistamine effects when combined with other agents that share these properties such as benztropine or diphenhydramine. Similarly, antihypertensive drugs may exacerbate the orthostatic hypotension induced by TCAs. 

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