Gastroparesis is a commonly diagnosed gastrointestinal disorder with a high prevalence globally and high disease burden to those afflicted with it. Etiologies are variable with idiopathic and diabetes being the most common causes of gastroparesis. Management of gastroparesis depends on the etiology, and accurate diagnosis is required for better targeted therapy. Medication-induced gastroparesis is reversible, and discontinuing the medication is generally curative. This case report discusses 2 cases of medication-induced gastroparesis which were initially diagnosed as diabetic gastroparesis, and thorough history taking revealed the cause to be medication induced. Repeat studies following medication discontinuation revealed improvement in symptoms and resolution of gastroparesis. Further research needs to be done to assess the frequency of misdiagnosing diabetic patients with gastroparesis due to medications, specifically glucagon-like peptide-1 receptor agonists which are increasingly being used in diabetics.

Metoclopramide has been the cornerstone of gastroparesis management for the past 40 years as it is the only FDA-approved medication for gastroparesis. Other medications such as erythromycin and domperidone have been used off-label with variable efficacy. Historically, metoclopramide has been used in oral, intravenous, and subcutaneous formulations. It is an antiemetic and prokinetic medication that acts through the inhibition of central (chemoreceptor trigger zone) and peripheral dopaminergic and serotogenic receptors. Due to its antidopaminergic effects, extrapyramidal symptoms have been reported, with the most feared adverse event being tardive dyskinesia. Subsequently, the FDA issued a metoclopramide black box warning label in February 2009 due to its risk of causing tardive dyskinesia, which can be irreversible. The incidence and prevalence of tardive dyskinesia among metoclopramide users have been variable in different studies. However, upon review of the current literature, the true prevalence of tardive dyskinesia seems to be lower than previously thought. This review will focus on metoclopramide and the extrapyramidal symptoms associated with its use.

Advances in the management of diabetes mellitus have come a long way in the 21st century. One of the most important developments in diabetes management has been the discovery of glucagon-like peptide-1 (GLP-1) receptor agonists. The most common side effects of GLP-1 receptor (GLP-1R) agonists are nausea and vomiting which have been attributed to delayed gastric emptying. While the effects of GLP-1R agonists on gastric emptying have prompted further research in this field, there are limited studies evaluating their effects on patients with pre-existing gastroparesis. Additionally, the frequency of GLP-1R agonist use among patients with gastroparesis has not been assessed in the past and this study aims to identify that percentage along with evaluating for possible iatrogenic gastroparesis. A retrospective review of all the gastric emptying studies performed at one academic medical center between January 2019 and January 2021 was performed. We found that although patients on GLP-1R agonists were more likely to have delayed gastric emptying, we could not establish a statistical significance. This could be due to the small sample size in the study. However, GLP-1R agonists use was associated with delayed gastric emptying in patients with diabetes for <10 years. Moreover, a significant proportion (24%) of patients with diabetes with delayed gastric emptying were on a GLP-1R agonist. Recently, semaglutide (GLP-1R agonist) gained Food and Drug Administration approval as a weight loss medication in both patients with and without diabetes. This should prompt further research to evaluate the safety profile of these medications in patients with and without pre-existing gastroparesis.

Giardia lamblia is a protozoan that results in the commonly diagnosed giardiasis. Due to its prevalence and incidence worldwide, it is essential to recognize the different presentations of giardiasis, routes of transmission, modalities of diagnosis, treatments, and complications. Diagnostic modalities have evolved over the years and can be achieved reliably through noninvasive stool testing. Endoscopic duodenal aspirate and biopsies can also be used; however, they yield lower sensitivity and specificity rates and are therefore not used as a first-line modality for diagnosing giardiasis. Nonetheless, its use should be considered in cases with high suspicion and unremarkable stool testing. Herein, we discuss the case of a 27-year-old male with chronic weight loss and abdominal pain for six months diagnosed with G. lamblia through a duodenal biopsy.

Acute intermittent porphyria (AIP) is a rare autosomal dominant inherited disease, predominantly seen in female patients, caused by mutations in the hydroxymethylbilane synthase gene. When impaired, elevated heme biosynthesis precursor levels accumulate in the liver, resulting in neurological symptoms, psychiatric disturbances, darkened urine color, abdominal pain, nausea, vomiting, and ileus. We present a 22-year-old Hispanic female with diffuse abdominal pain and no bowel movements for 8 days. She reported recent antibiotic and oral contraceptive pill use. Computerized tomography of her abdomen revealed a dilated small bowel and marked colonic distension. A colonoscopy found mild nonspecific inflammation in the rectosigmoid and terminal ileum. Her abdominal pain persisted despite interventions and improvements in appetite, bowel movements, abdominal imaging, and treatment of an identified Clostridium difficile infection. A random urine porphobilinogen was then obtained and found to be elevated. Fractionation of plasma and urine porphyrins was suggestive of AIP. Her symptoms improved with 3 days of intravenous (IV) hematin and IV dextrose. This is a unique case of a rare disease due to her clinical presentation with ileus, unremarkable past medical history, family history, and the prehospitalization and intrahospitalization factors that likely exacerbated the patient AIP.

Methemoglobinemia is a rare cause of hypoxia and can be a diagnostic challenge early in the disease course. The incidence of medication-induced methemoglobinemia is more common than congenital-related methemoglobinemia. The most common cause of methemoglobinemia is exposure to household detergents, illicit drugs, or medications with nitrate or sulfonamide chemical groups. The 2 main medications accounting for up to 45% of medication-induced cases are dapsone and benzocaine. We report a case of hypoxia and diarrhea with an arterial blood gas (ABG) showing methemoglobinemia at 26%. Infectious and autoimmune workup were negative. Methemoglobinemia level returned to normal level within 2 weeks of hydrochlorothiazide discontinuation, suggesting medication-induced methemoglobinemia at appropriate hypertension dosage. In this case, there was an acute rise in methemoglobin levels following initiation of an hydrochlorothiazide-losartan combination, which improved following the discontinuation of hydrochlorothiazide. Extensive workup ruled out cytochrome b5 reductase (Cb5R) and Glucose-6-phosphate dehydrogenase (G6PD) deficiency, which raised the suspicion of hydrochlorothiazide-induced methemoglobinemia, as it is part of the sulfa drug family.