Side effects of opioids (strong painkillers)

Opioids draw water out of your stool and slow down the muscles in your gut. This makes your stools hard and difficult to pass. Sometimes it’s not easy to know if you are constipated. If your stools are hard, if you are going less often, or if you are straining to go – you are constipated.

Unless your doctor tells you otherwise, when you are on opioid medicines you should be taking medicines to prevent constipation, which are called laxatives. Tap to learn more about constipation.

Sleepiness or drowsiness are common symptoms of cancer and cancer treatment. Opioids (especially short-acting opioids, also known as “breakthrough” pain medications) can also cause drowsiness. Drowsiness is usually worse for a few days after starting an opioid or increasing the dose. It often clears up on its own, so be patient. If your drowsiness does not clear up within 3 days of starting a new dose, here are some changes you might try. Little changes can make a big difference.

• Avoid taking your opioids at the same time as other medicines that cause sleepiness. Here are a few common medicines that can make you feel drowsy:

  • Nausea medicines: Compazine (prochlorperazine), Phenergan (promethazine), Ativan (lorazepam)

  • Anxiety medicines: Ativan (lorazepam), Xanax (alprazolam), Klonopin (Clonazepam)

  • Allergy medicines: Benadryl, Zyrtec, Claritin

  • Other pain medicines: Neurontin (gabapentin), Lyrica (pregabalin)

• If your short-acting opioid is prescribed with a range of doses, start with the lowest dose first and work your way up.

• Try using fewer opioids at times that you need to be most alert.

• If you can have caffeine, try a beverage like coffee or green tea.

• Ask your doctor about medicines that might help you be more awake during the day.

Cancer and cancer treatment commonly cause fatigue. Opioids can make fatigue worse. Fatigue is an overwhelming sense of tiredness, lack of energy, or feelings of exhaustion. If you notice that you’re getting sleepy or nodding off after taking your opioids, this sounds more like drowsiness.

Read more here about some good ways to manage your fatigue and improve your energy.

You may feel nauseous when you’re taking opioids, but it should go away after a few doses. If it doesn’t, here are a few things that might help:

• Try taking an anti-nausea pill (like Compazine or Zofran) about 30 minutes before taking your opioid

• Try drinking ginger tea

• Some people find that eating a small snack before taking your opioid may help

• Try resting for about an hour after taking your pain medicine, so your stomach can settle

• If your nausea continues, talk to your care team

Some people taking opioids describe feeling foggy, or not as sharp as usual. This can improve with time.

• For some people, feeling foggy can be just as bothersome as having severe pain. For others, it’s more important to have their pain under control. Only you can decide the right balance for you.

• If fogginess doesn’t go way, try using your opioids at times of day when you don’t need to be as sharp (like while watching TV).

• Talk to your care team about these symptoms. Sometimes other medications can help balance out feeling foggy.

Rarely, people feel dizzy or light headed after taking an opioid. If you’re experiencing this, you should discuss your symptoms with your care team.

Dizziness sometimes happens when someone stands up after sitting or lying down for a while, especially if a person’s blood pressure runs low. Here are some things you can try:

• Make sure to drink plenty of water (at least 8 cups per day). Dizziness may happen if you’re dehydrated.

• Change positions slowly to give your body time to adjust

• Sit on the edge of the bed for a few minutes before standing up.

• If you are still feeling dizzy after a few minutes, don’t stand up.

• Hold onto something when you stand up., sit back down if you feel dizzy when you stand up so that you don’t fall.

Call your care team if you have new or worsening dizziness.

Being in pain and taking opioids can cause changes to your sexual health. It can be easy to overlook the importance of sexual intimacy. But feeling intimacy and connection can be an important part of coping with pain and cancer in general.

Read more here about changes in sexual health.

Opioids can affect how you feel, and this can be different for everyone.

Some people describe feeling sad or irritable with opioids. Other say they feel moody or more emotional.

On the other hand, when opioids help to reduce your pain, your mood is likely to improve. Being in pain is depressing. Being depressed makes pain worse. It’s a vicious cycle. This is why having a pain medicine plan can be a really important way to improve your mood.

If mood changes are greatly interfering with your daily life, talk to your care team. You can also read more here about how emotions and pain are connected.

It is not rare or harmful for some people who use opioid medications to feel unusually happy or good when they take them. This is because of how the medication affects the emotional part of the brain.

If you are taking your opioid medication the way it was prescribed, these feelings may go away when your body gets used to the medicine.

If this feeling makes you worried, talk to your care team.

Some people notice their mouth feels dry when taking opioids. This is because opioids can slow down how much saliva (spit) your mouth makes. Dry mouth can also be caused by other medications, especially chemotherapy.

Here are some things you can try:

• Sip on water or suck on ice chips

• Try things that create more saliva (spit) in your mouth

  • Suck on slices of lemon, lime, or other citrus fruits (avoid if you have mouth sores from chemo or any other reason)

  • Suck on sour candies

  • Chew sugar free gum

• Try using alcohol-free mouth wash, or salt-water rinses a few times per day

• Try using Biotene® mouthwash, lozenges, or toothpaste. These are moisturizing for your mouth and can feel soothing

• Avoid alcohol-containing mouthwashes

If your mouth is uncomfortably dry, call your care team or dentist and ask about more things you can do to help.

Some people may notice difficultly starting the flow of urine (pee) or having a weak flow. This is not a common opioid side effect. If you already had troubles urinating before taking opioids (for example - if you have an enlarged prostate), opioids can make this worse.

Difficulty urinating is not usually serious, but occasionally it can represent a bigger problem that needs evaluation and treatment.

If you have new or worsening trouble passing urine, contact your care team.

These are quite rare, but serious potential side-effects. Hallucinations are:

• Seeing things that others don’t see

• Hearing things that others don’t hear

• Having difficulty knowing what’s real and what’s not

If you experience any of the following symptoms, call your care team right away.