Naltrexone Side Effects

Like all medications, Naltrexone can cause side effects. Most people do not experience serious adverse effects, but it is important to know what to look for and when to seek medical care.

Common Side Effects

→Constipation (very common, may require laxatives)
→Nausea and vomiting especially when initiating
→Sedation and drowsiness
→Dry mouth
→Pruritus (itching)

Serious Side Effects

→Respiratory depression (life-threatening overdose)
→Physical dependence and withdrawal
→Opioid use disorder
→Severe constipation or bowel obstruction
→Urinary retention

When to Seek Medical Care

→Breathing that is slow, shallow, or difficult
→Extreme drowsiness or unresponsiveness
→Blue lips or fingernails
→Severe constipation for more than 3 days
→Signs of allergic reaction

Safety Note

If you experience any unexpected or concerning symptoms while taking Naltrexone, contact your doctor or pharmacist. Do not stop taking Naltrexone without medical advice unless you experience a serious adverse reaction.

Frequently Asked Questions

Are side effects from Naltrexone common?

Most patients tolerate Naltrexone well at therapeutic doses. Common side effects are usually mild and often improve after the first few weeks. Serious side effects are less common but should be reported immediately.

What should I do if I experience side effects from Naltrexone?

Mild side effects: discuss with your pharmacist, as many resolve spontaneously. Serious side effects: seek medical care immediately and contact your prescriber. Do not stop Naltrexone abruptly for long-term conditions without medical advice.

More About Naltrexone

Dosage & Administration

Drug Interactions

Warnings & Precautions

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Medical Disclaimer: This drug reference is provided for informational purposes only and is not a substitute for professional medical advice. Always consult your physician or pharmacist before changing your medication. Information reviewed by the vHospital Editorial Team · Sources: WHO, BNF, FDA prescribing information.