Naltrexone is a medication primarily used to help individuals manage alcohol use disorder and opioid use disorder. This medication works by blocking the effects of opioids in the brain, which can help reduce cravings for alcohol and opioids. Nausea is a common side effect for those taking this medication.
Nausea as a Common Side Effect
Nausea is frequently reported among individuals taking naltrexone, making it one of the most common side effects for both oral tablets and intramuscular injections. This sickness begins when treatment is initiated or following the first dose of an injection. For most, nausea is mild to moderate and temporary. It subsides within a few days to a few weeks as the body adjusts to the medication.
Digestive issues such as vomiting, diarrhea, or abdominal pain may also occur alongside nausea. While uncomfortable, nausea from naltrexone rarely leads to treatment discontinuation.
Understanding Why Nausea Occurs
Nausea associated with naltrexone arises from its fundamental action as an opioid receptor antagonist. Naltrexone binds to and blocks opioid receptors, particularly mu-opioid receptors, found in the brain and throughout the gastrointestinal tract. By blocking these receptors in the gut, naltrexone can influence gastrointestinal motility, slowing down the digestive process. When food lingers longer in the stomach, it can contribute to feelings of fullness and discomfort, leading to nausea.
Naltrexone’s interaction with opioid receptors also affects the brain’s chemoreceptor trigger zone, an area involved in the sensation of nausea. This interaction can alter neurotransmitter activity, influencing the signals that control the vomiting reflex. Prior alcohol consumption can influence the body’s endogenous opioid system. How recently and intensely someone has consumed alcohol before starting naltrexone influences the risk of experiencing nausea, with longer periods of abstinence reducing this risk.
Strategies for Managing Nausea
Several practical approaches can help manage naltrexone-induced nausea. Taking the medication with food or immediately after a meal can significantly reduce stomach upset. Staying well-hydrated by drinking plenty of fluids throughout the day is beneficial. Avoiding foods that are spicy, fried, or high in fat can relieve digestive discomfort.
Adjusting the timing of the dose can also be helpful; while many take naltrexone in the morning, some prefer to take it at night if they experience daytime sleepiness or dizziness. Taking it in the morning can lessen intense dreaming for some users. For those starting treatment, a healthcare provider may recommend beginning with a lower dose, such as 25 mg, and gradually increasing it to the standard 50 mg to allow the body to slowly adjust. Over-the-counter remedies like ginger or bismuth can also provide relief from nausea.
It is important to discuss any persistent or bothersome nausea with a healthcare professional, who can offer personalized advice, consider anti-nausea medications, or explore alternative dosing strategies. Ensuring that opioids or alcohol are not in one’s system before starting naltrexone is also important, as their presence can intensify side effects like nausea.