Naltrexone is a medication used to support individuals managing alcohol or opioid dependence, helping reduce cravings and the rewarding effects of these substances. While generally well-tolerated, individuals starting naltrexone may experience side effects. Nausea is one of the most commonly reported side effect across both forms of the medication.
Why Naltrexone Can Cause Nausea
Naltrexone functions as an opioid antagonist, blocking opioid receptors in the body. This action directly influences the gastrointestinal tract, where these receptors are abundant. By blocking them, naltrexone can increase gut motility and disrupt normal digestive processes, leading to discomfort or nausea.
Naltrexone also affects opioid receptors in the brain. The brain’s chemoreceptor trigger zone (CTZ), which plays a role in nausea and vomiting, can be indirectly influenced by these changes, contributing to the sensation of nausea.
How Long Naltrexone Nausea Lasts
The duration of naltrexone-induced nausea varies, but it typically resolves as the body adjusts to the medication. For most, nausea is mild and tends to subside within a few days to a couple of weeks after starting treatment. This initial period allows the body to adapt to the medication’s presence and its effects on the opioid receptor system.
Factors influencing how long nausea may persist include individual sensitivity, dosage, and medication form (oral or injectable). Oral naltrexone side effects often improve within two to four weeks. For the injectable form, nausea is most common after the first injection and generally improves within a few days. Persistent or worsening nausea beyond this initial adjustment period is less common.
Strategies for Managing Nausea
Several approaches can help manage naltrexone-induced nausea. Taking the medication with food can reduce stomach upset and discomfort. Eating smaller, more frequent meals may also help ease digestive symptoms.
Gradually increasing the dosage can allow the body to adjust smoothly. Maintaining hydration by drinking plenty of fluids is beneficial. Avoiding greasy, spicy, or irritating foods can alleviate nausea. Some find relief with over-the-counter remedies like ginger or antacids; consult a healthcare provider before use.
When to Seek Medical Advice
While naltrexone-induced nausea is often temporary and manageable, certain symptoms warrant medical attention. Contact a healthcare professional if you experience severe or persistent vomiting that prevents keeping down fluids. Signs of dehydration, such as decreased urination or dizziness, also require prompt medical evaluation.
Other concerning symptoms include severe abdominal pain. Signs of potential liver problems, such as yellow skin or eyes (jaundice), dark urine, or clay-colored stools, require medical consultation. Any new or worsening symptoms should also be discussed with a healthcare provider.