Patient B: Buproprion-Naltrexone

Patient B stated he has been taking buproprion-naltrexone (Contrave) for symptoms and has been titrating his dosage up to take two tablets, twice daily. Buproprion-naltrexone is a combination of an opioid antagonist and a weak inhibitor of neuronal reuptake of dopamine and norepinephrine. Its mechanism for weight loss is not fully understood, but it is approved for use in chronic weight management.⁶ It is contraindicated with concurrent use of bupropion-containing medications or other opioid antagonists, as well as in acute opioid withdrawal, uncontrolled hypertension, eating disorders, and seizure disorders. Buproprion-naltrexone can be associated with nausea, constipation, headache, vomiting, dizziness, insomnia, dry mouth, diarrhea, and renal impairment. It has also been associated with increases in heart rate and blood pressure.⁷ Patients are expected to titrate the medication up over time; however, they require guidance on therapeutic ceiling and to ensure they do not continue taking this medication if not efficacious. Patient B’s symptoms improved with intravenous fluids, antiemetics, and over-the-counter analgesia in the acute setting. Similarly to the management of other causes of nausea and vomiting, labs to assess for metabolic function, renal function, and acute infection should be considered. Risk stratification of headache, including a full neurological examination to assess central versus peripheral etiologies, and appropriate imaging should also be considered.

Patient B’s symptoms improved with intravenous fluids, antiemetics, and over-the-counter analgesia. On follow-up with his primary care physician, titrating his buproprion-naltrexone dose down resulted in normalization of his creatinine and resolution of his symptoms.

Patient C: Orlistat

Oily stool, also known as steatorrhea, is associated with the secretion of lipids in the gastrointestinal tract. The differential includes any intraabdominal process, such as celiac disease, tropical sprue, exocrine pancreatic insufficiency, malabsorption due to small intestinal disease, and bariatric surgery.⁸ However, medications can also cause this. Orlistat (Xeical, Alli) is a reversible inhibitor of gastric and pancreatic lipases. It inhibits absorption of dietary fats; thus, they are secreted in the stool and can frequently cause steatorrhea, fecal spotting, and diarrhea.⁹ Orlistat can also cause diffuse abdominal pain, anal fissures, hepatotoxicity, and acute kidney injury. It is contraindicated in chronic malabsorption syndromes, cholestasis, and patients with existing absorption issues secondary to prior surgical resection, such as bariatric surgery. This patient had her first seizure in years despite adherence to her valproate for management of her epilepsy. One side effect of this medication is that it can reduce the absorption of antiepileptic medications such as valproate, vigabatrin, and lamotrigine and reduce their plasma concentration, thus putting patients taking these medications at higher risk of seizure.¹⁰ Patients taking orlistat should have regular assessment of their levels of antiepileptic medications and dosing adjustments as needed. It also has the potential to decrease absorption of other medications such as amiodarone, warfarin, levothyroxine, cyclosporine, and antiretroviral medications. Similarly, consideration of subtherapeutic dosing should be considered for patients with relevant history. A high suspicion for toxic and metabolic impacts of orlistat in caring for patients with multiple comorbidities and polypharmacy is needed.