From the Guidelines
Isotretinoin causes diarrhea and vomiting primarily through its irritant effects on the gastrointestinal tract and its influence on mucosal secretion. As a vitamin A derivative, isotretinoin affects epithelial cells throughout the body, including those lining the digestive system. The medication directly irritates the gastric and intestinal mucosa, which can trigger inflammatory responses leading to nausea, vomiting, and diarrhea, as noted in the guidelines of care for the management of acne vulgaris 1. Additionally, isotretinoin alters mucus production and secretion in the gut, potentially disrupting the protective barrier of the digestive tract. The drug may also affect gut motility by influencing smooth muscle function and altering intestinal transit time. Some patients experience these side effects due to isotretinoin's impact on bile acid metabolism, which can lead to malabsorption and subsequent diarrhea.
These gastrointestinal side effects typically occur in about 20% of patients taking standard doses (0.5-1 mg/kg/day) and are usually dose-dependent, meaning higher doses increase the likelihood and severity of these symptoms, similar to the dose-dependent effects seen with other medications like TKIs 1. Patients can minimize these effects by taking isotretinoin with food and maintaining adequate hydration throughout treatment. It's also important to note that while the exact mechanism of isotretinoin-induced diarrhea and vomiting is multifactorial, the medication's influence on the gastrointestinal tract is a primary factor, and managing these side effects is crucial to improve patient outcomes and quality of life.
Key points to consider:
- Isotretinoin's effects on the gastrointestinal tract are a primary cause of diarrhea and vomiting
- The medication's influence on mucosal secretion and epithelial cells contributes to these side effects
- Dose-dependent effects are observed, with higher doses increasing the likelihood and severity of symptoms
- Patients can minimize these effects by taking isotretinoin with food and maintaining adequate hydration throughout treatment, as recommended in the guidelines of care for the management of acne vulgaris 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Mechanism of Isotretinoin-Induced Diarrhea and Vomiting
- The exact mechanism by which isotretinoin causes diarrhea and vomiting is not fully understood, but it is believed to be related to its effects on the intestinal mucosae 2.
- Isotretinoin can cause damage to the intestinal mucosae, leading to adverse effects such as bloody and mucousy diarrhea, colitis, and ileitis 2.
- The drug can affect all mucous membranes, causing multiple disorders of varying severity, including gastrointestinal tract disorders such as colitis 2.
- There is no clear explanation for how isotretinoin causes diarrhea and vomiting, but it is thought to be related to its anti-inflammatory and immunoregulatory properties 3.
- Other studies have reported that isotretinoin can cause a range of adverse effects, including mucocutaneous side effects, but do not provide a clear mechanism for how it causes diarrhea and vomiting 4, 5, 6.