A patient with a history of chronic alcohol abuse has been admitted to the unit with cirrhosis. Upon review of the patient's laboratory test results, the nurse notes that the patient's ammonia level is elevated at 218 mcg/dL. What medication should the nurse prepare to administer?

Choice A reason:
Loss of muscle tone at the lower esophageal sphincter (LES) is the primary cause of GERD. The LES normally prevents stomach contents from refluxing into the esophagus. When its tone is reduced, acidic gastric contents can flow back, leading to symptoms such as heartburn, regurgitation, and potential damage to the esophageal lining. Factors contributing to LES dysfunction include obesity, hiatal hernia, and certain dietary habits.
Choice B reason:
Sympathetic nerve stimulation is not a cause of GERD. The autonomic nervous system plays a role in regulating digestive functions, but GERD is primarily a mechanical issue involving the LES and is not directly related to sympathetic nervous activity.
Choice C reason:
Fibrosis of the lower third of the esophagus is typically associated with conditions such as scleroderma, which can lead to esophageal motility disorders. While fibrosis might contribute to esophageal dysfunction, it is not the primary cause of GERD.
Choice D reason:
Reverse peristalsis of the stomach is not a mechanism for GERD. GERD results from dysfunction of the LES, not from the backward movement of stomach contents due to altered motility.

Choice A reason:
In patients with chronic renal failure, the kidneys cannot effectively excrete magnesium, leading to the risk of hypermagnesemia. Magnesium hydroxide, commonly used as an antacid and laxative, should be used with caution or avoided in these patients to prevent magnesium accumulation in the blood, which can have serious cardiovascular and neuromuscular effects.

Choice B reason:
While cirrhosis affects liver function and can alter drug metabolism, magnesium hydroxide does not have a direct contraindication for use in patients with cirrhosis. However, caution is necessary due to potential electrolyte imbalances and altered pharmacokinetics. The primary concern with magnesium hydroxide in these patients is less critical compared to those with renal failure.

Choice C reason:
Hemorrhoids do not directly contraindicate the use of magnesium hydroxide. This condition primarily affects the veins around the rectum and anus and is unrelated to the systemic effects of magnesium. Therefore, the presence of hemorrhoids does not necessitate withholding the medication.

Choice D reason:
Undiagnosed abdominal pain is a significant consideration before administering magnesium hydroxide. The use of laxatives can exacerbate conditions like intestinal obstruction or acute abdomen. Therefore, caution is advised, but the immediate and more critical concern remains the risk posed to patients with chronic renal failure.