A client admitted to the hospital with suspected myasthenic crisis was prescribed edrophonium (Tensilon). The nurse misread the dosage and administered a higher dose than prescribed. The doctor has ordered an antidote to be given. What medication does the nurse anticipate administering?

Choice A reason: Atropine is an anticholinergic medication that blocks the effects of the parasympathetic nervous system. One of its effects is relaxation of the smooth muscles in the bladder, which can lead to urinary retention. This occurs because the bladder's ability to contract is inhibited, making it difficult for the patient to void.

Choice B reason: Bradycardia is not an expected effect of atropine. In fact, atropine is often used to treat bradycardia by increasing heart rate. It works by blocking the vagus nerve's influence on the heart, which normally acts to slow the heart rate. Therefore, atropine would be expected to cause an increase in heart rate, not a decrease.

Choice C reason: Diarrhea is not a common effect of atropine. Atropine works by reducing the activity of the gastrointestinal tract, leading to a decrease in bowel movements and potentially causing constipation rather than diarrhea. Anticholinergic drugs like atropine reduce gastrointestinal motility, which can lead to a slower passage of food through the intestines.

Choice D reason: Vomiting is not typically associated with the administration of atropine. While nausea and vomiting can be side effects of many medications, atropine more commonly causes dry mouth, blurred vision, and constipation. The medication's action on the gastrointestinal tract tends to slow digestive processes rather than stimulate vomiting.

Choice A reason: Sodium bicarbonate is used to treat metabolic acidosis and is not indicated for symptomatic bradycardia.

Choice B reason: Atropine is the first-line medication for symptomatic bradycardia. It works by blocking the vagus nerve's effects on the heart, increasing heart rate. It is commonly used in emergency settings to manage bradycardia until a more definitive treatment, such as pacemaker insertion, can be provided.

Choice C reason: Magnesium is typically used to treat torsades de pointes, a specific type of ventricular tachycardia, and is not indicated for symptomatic bradycardia.

Choice D reason: Amiodarone is an antiarrhythmic medication used to manage various types of arrhythmias, including ventricular tachycardia and fibrillation, but it is not indicated for symptomatic bradycardia.