Can I take Lactulose and Oxycodone together?

Why this happens

Oxycodone slows down the movement of the digestive system (gut motility). Lactulose works by drawing water into the bowel to soften stools and stimulate movement. These two medications have opposing effects on the speed of your digestive tract.

What you should do

It is safe and very common to take these together, but you should monitor your bowel habits. If you remain constipated despite taking lactulose, speak to your doctor or pharmacist, as you may need a different type of laxative (such as a stimulant laxative) to counteract the effects of the oxycodone. Ensure you drink plenty of water.

Important precautions

Respiratory conditions (e.g. COPD, severe asthma)

Oxycodone can cause life-threatening breathing difficulties; do not take this if you have severe lung disease or breathing problems.

Opioid dependence/Addiction

Oxycodone is addictive and can cause withdrawal symptoms; it should only be used for short periods as prescribed.

Galactosaemia

You must not take lactulose if you have galactosaemia, a rare genetic disorder where your body cannot process galactose.

Diabetes

If you are taking high doses of lactulose for liver disease (portal systemic encephalopathy), the sugar content may affect your blood glucose levels.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol while taking oxycodone. Combining alcohol with opioid painkillers like oxycodone significantly increases the risk of dangerous side effects, including extreme sleepiness, breathing difficulties, and a potentially fatal overdose.

It is best to avoid or strictly limit alcohol when taking lactulose. Alcohol can cause dehydration, which may worsen the constipation you are trying to treat. Additionally, if you are taking lactulose for liver disease (hepatic encephalopathy), alcohol must be avoided entirely as it can significantly worsen your condition.

Grapefruit juice

Avoid drinking grapefruit juice or eating grapefruit while taking oxycodone. Grapefruit can interfere with how your body breaks down the medicine, leading to higher levels of oxycodone in your blood, which increases the risk of serious side effects.

Water and Fluids

It is essential to drink plenty of fluids (such as water) while taking lactulose. This medicine works by drawing water into the bowel to soften stools; if you do not drink enough, the medicine may not work effectively and you may become dehydrated.

Using other medicines

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.