ooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. Opiate analgesics combined with antimuscarinics can cause severe constipation or paralytic ileus, especially with chronic use. Pharmacology texts report that meperidine exerts less pronounced effects on GI smooth muscle than other opiate agonists.
Fexofenadine; Pseudoephedrine: Atropine blocks the vagal reflex bradycardia caused by pseudoephedrine, and increases its pressor effect. Patients need to be asked whether they have taken pseudoephedrine before receiving atropine.
Fluoxetine; Olanzapine: The anticholinergic effects of atropine may be enhanced when combined with other drugs with moderate to significant anticholinergic effects including olanzapine. Clinicians should note that antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. Additive drowsiness may also occur.
Fluphenazine: Additive anticholinergic effects may be seen when anticholinergics are used concomitantly with phenothiazines, including fluphenazine. Clinicians should note that antimuscarinic effects may be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. Additive drowsiness or other additive CNS effects may also occur.
Food: Avoid administering marijuana and atropine together as concurrent use may result in adverse cardiovascular effects, such as tachycardia and cardiac arrhythmias. Marijuana is known to produce significant increases in heart rate and cardiac output lasting for 2-3 hours. Further, rare case reports of myocardial infarction and cardiac arrhythmias have been associated with marijuana use. Atropine has also been reported to produce a wide range of cardiovascular effects including asystole, atrial fibrillation, premature ventricular contractions (PVCs), ventricular fibrillation, palpitations, and sinus tachycardia. Coadministration of marijuana with atropine may result in significant cardiovascular adverse events and thus, should be avoided.
Galantamine: The therapeutic benefits of galantamine, a cholinesterase inhibitor, may be diminished during chronic co-administration with antimuscarinics or medications with potent anticholinergic activity. When concurrent use is not avoidable, the patient should be monitored for cognitive decline and anticholinergic side effects. Clinicians should generally avoid multiple medications with anticholinergic activity in the patient with dementia. Some of the common selective antimuscarinic drugs for bladder problems, (such as oxybutynin, darifenacin, trospium, fesoterodine, tolerodine, or solifenacin), do not routinely cause problems with medications used for dementia, but may cause anticholinergic side effects in some patients. Atropine may be used to offset bradycardia in cholinesterase inhibitor overdose.
Glucagon: The concomitant use of intravenous glucagon and anticholinergics increases the risk of gastrointestinal adverse reactions due to additive effects on inhibition of gastrointestinal motility. Concomitant use is not recommended.
Guaifenesin; Hydrocodone: Concurrent use of antidiarrheals and hydrocodone can lead to severe constipation and possibly additive CNS depression. Opiate analgesics combined with antimuscarinics can cause severe constipation or paralytic ileus, esp |
