Peripheral treatments, though they do not address the causes of hormonal hypersecretion, may provide beneficial relief of the symptoms of carcinoid syndrome.
Antidiarrheal Agents
A variety of different pharmacologic agents have been used to treat diarrhea. Antidiarrheals can be divided into 3 main categories, depending on their mode of action: antimotility agents, adsorbent agents, antisecretory agents, and bacterial replacement agents.
Adapted with permission from Longe et al1.
Antimotility Agents1,2
- Atropine
- Diphenoxylate (eg, Lomotil® , GD Searle & Co)
- Loperamide (Imodium® , Janssen Pharmaceutical Inc)
- Paregoric (eg, Paregoric USP, Barre-National Inc)
- Opium tincture, "DTO" (deodorized tincture of opium) (Parepectolin® , Rhône-Poulenc Rorer Pharmaceuticals Inc.)
Characteristics:
- Reduce propulsive activity of the gut and thus reduce stool frequency and volume in most patients2
- Slow transit time (contact between intraluminal contents and the intestinal mucosa increases), thereby enhancing the potential for absorption2
- Potential risk of addiction if diarrhea is chronic and the agent must be used for prolonged periods1
Adsorbent Agents1
- Kaolin-pectin mixture (eg, Kaopectate® , The Upjohn Company)
- Kaolin-pectin suspension (Roxane Laboratories, Inc)
- Polycarbophil (eg, Mitrolan® Tablets, AH Robins Company)
Characteristics
- Nonspecific agents that act by binding intraluminal contents through surface adhesion
- Generally, do not require a prescription
- Indicated for symptomatic relief and may have limited value in chronic diarrhea
- Bind intraluminal contents indiscriminately—toxins, digestive secretions, nutrients, and drugs
Antisecretory Agents1
- Bismuth subsalicylate (Pepto-Bismol® , Procter & Gamble)
Characteristics:
- Contain ingredients that are toxic at high doses
- Excipients such as salicylates can cause nausea, vomiting, and tinnitus, and can interfere with blood coagulation
- Bismuth also poses a risk for toxicity at high doses
Bacterial Replacement Agents1
- Lactobacillus acidophilus (Bacid® Capsules, Fisons Corporation)
- Lactobacillus bulgaricus and L. acidophilus (Lactinex® Tablets and Granules, Hynson, Westcott & Dunning Products)
Important Safety Information
Carcinoid Syndrome:
Sandostatin® LAR Depot (octreotide acetate for injectable suspension) is indicated for long-term treatment of the severe diarrhea and flushing episodes associated with metastatic carcinoid tumors and for the long-term treatment of the profuse watery diarrhea associated with VIP-secreting tumors in patients in whom initial treatment with immediate release Sandostatin® (octreotide acetate) Injection has been shown to be effective and tolerated.
Important Safety Information:
As with immediate release Sandostatin® Injection, the most frequently reported drug-related adverse events were biliary disorders (62%), gastrointestinal disorders (14% to 38%), and injection-site pain (20% to 50%). Hypoglycemia (4%), hyperglycemia (27%), sinus bradycardia (19%), conduction abnormalities (9%), and arrhythmias (3%) have been reported.
The controlled clinical trials that support the marketing clearance for Sandostatin® LAR Depot did not include determination of effect on tumor size or rate of growth. Sandostatin® LAR Depot is not indicated for tumor shrinkage.
Acromegaly
Sandostatin® LAR Depot (octreotide acetate for injectable suspension) is indicated for long-term maintenance therapy in acromegalic patients who have had an inadequate response to surgery and/or radiotherapy, or for whom surgery and/or radiotherapy is not an option. The goal of treatment in acromegaly is to reduce GH and IGF-1 levels to normal.
Important Safety Information:
As with immediate release Sandostatin® Injection, the most frequently reported drug-related adverse events were biliary disorders (52%), gastrointestinal disorders (7% to 36%), and injection-site pain (2% to 11%). Hypoglycemia (2%), hyperglycemia (15%), and hypothyroidism (2%) have been reported. While not measured in acromegalic patients receiving Sandostatin® LAR Depot, ECG changes have been reported in patients receiving immediate release Sandostatin® Injection; the degree to which these abnormalities are related to octreotide acetate is not clear, as many acromegalics have cardiovascular disease. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.
