What is pain medications?

Pain medicine side effects in children: Overview

When you take your child for medical care, your child may get strong medicine called an opioid to help with pain. Some examples are fentanyl and morphine. The medicine may be given in a vein (by I.V.). Or it may be given as an injection (shot). These medicines help relieve your child's pain. But they also have side effects.

It's important that you know how this strong pain medicine affects your child. Common side effects can include:

  • Constipation.
  • Nausea or vomiting.
  • Feeling dizzy or lightheaded.
  • Feeling sleepy.

The doctor has checked your child carefully, but problems can develop later. If you notice any problems or new symptoms, get medical treatment right away.

What medicines are used to treat cancer pain?

Many different medicines are used to treat cancer pain. Over-the-counter medicines may relieve your pain at times. But you may need stronger medicines that your doctor prescribes. These may be used alone or with other medicines.

If you already take pain medicine for another problem, tell your doctor how often you take it and how well it works.

Over-the-counter pain relievers

Pain medicines that you can buy without a prescription include:

  • Acetaminophen, such as Tylenol.
  • Anti-inflammatory medicines, which also reduce swelling. Examples include:
    • Ibuprofen, such as Advil or Motrin.
    • Naproxen, such as Aleve or Naprosyn.
    • Aspirin, such as Bayer or Ecotrin.

Be careful when taking these over-the-counter medicines.

  • Talk with your doctor before you take these medicines. This is especially important if you have a fever or have had kidney or liver disease, gastrointestinal bleeding, or a stomach ulcer.
  • Don't take more than the label says, unless your doctor tells you to do so.

Prescription medicines

These include:

Opioid pain relievers.
Examples are fentanyl, morphine, oxycodone, and tramadol. Fast-acting opioids may be prescribed for breakthrough pain.
Other medicines that may be used with opioid pain relievers.

These medicines may be given to help your pain medicine work better or to treat your symptoms. Or they may be given for certain types of pain. They include:

  • Seizure medicines (anticonvulsants). These can help control nerve pain, like burning and tingling.
  • Antidepressants. These can relieve pain and help you sleep.
  • Anti-inflammatory medicines and steroid medicines (such as prednisone and dexamethasone).
  • Bisphosphonates and other medicines to treat bone pain.
  • Local anesthetics to help relieve pain in the skin and surrounding tissues. Examples include skin creams with capsaicin or lidocaine.

These medicines may be stronger or work differently than over-the-counter medicines.

  • Be sure to follow your doctor's instructions when you take these stronger medicines. If you still have pain, call your doctor.
  • Some of these medicines may work better than others. It depends on the type of pain you have.

Some people use cannabis products. It's not clear whether cannabis helps cancer pain. Ask your doctor if you think you might want to try this.

How can you care for side effects from pain medicine?


  • Don't do anything for 24 hours that requires attention to detail, such as going to work, making important decisions, or signing any legal documents. Strong pain medicines like opioids can make your mind foggy. It takes time for the effects to wear off completely.
  • Don't drive a car until you are sure the effects from the medicine are gone.


  • Be safe with medicines. Read and follow all instructions on the label.
    • If the doctor gave you a prescription medicine for pain, take it as prescribed.
    • If you are not taking a prescription pain medicine, ask your doctor if you can take an over-the-counter medicine.


  • You can eat your normal diet, unless your doctor gives you other instructions. If your stomach is upset, try clear liquids and bland, low-fat foods like plain toast or rice.
  • If your strong pain medicine makes you feel constipated, talk to your doctor about a laxative. If a laxative doesn't work, your doctor may suggest a prescription medicine.
  • Drink plenty of fluids (unless your doctor tells you not to).
  • Don't drink alcohol for 24 hours after taking opioids.

How can you safely take pain medicines?

  • Be safe with medicines. If you take an over-the-counter pain medicine, such as acetaminophen (Tylenol), ibuprofen (Advil, Motrin), or naproxen (Aleve), read and follow all instructions on the label.
  • Do not give aspirin to anyone younger than 20. It has been linked to Reye syndrome, a serious illness.
  • Be careful when taking over-the-counter cold or flu medicines and Tylenol at the same time. Many of these medicines contain acetaminophen, which is Tylenol. Read the labels to make sure that you are not taking more than the recommended dose. Too much Tylenol can be harmful.
  • Do not take two or more pain medicines at the same time unless the doctor told you to.
  • Do not take pain medicines (like an opioid) with alcohol or with certain drugs like sleeping pills and muscle relaxers. This can slow down your breathing and cause an accidental overdose.
  • Safely store and dispose of opioids. Make sure that pets, children, friends, and family can't get to them.
  • If your pain pills make you constipated:
    • Talk to your doctor about a laxative. If a laxative doesn't work, your doctor might suggest a prescription medicine.
    • Drink plenty of fluids. If you have kidney, heart, or liver disease and have to limit fluids, talk with your doctor before you increase the amount of fluids you drink.
    • Take fiber, such as Citrucel or Metamucil, daily if needed. Read and follow all instructions on the label. If you take pain medicine for more than a few days, talk to your doctor before you take fiber.

Side effects of pain medicine in children: When to call

Call 911 anytime you think your child may need emergency care. For example, call if:

  • Your child has trouble breathing.
  • Your child passes out (loses consciousness).

Call your doctor now or seek immediate medical care if:

  • Your child has new or worse pain.
  • Your child is sleepy and confused.

Watch closely for changes in your child's health, and be sure to contact your doctor if:

  • Your child does not get better as expected.

How are medicines for cancer pain given?

Medicines for cancer pain are usually taken by mouth. But medicine can be given in other ways if you have trouble swallowing or need faster pain relief.

Pain medicine may be given:

By mouth.

This includes pills, capsules, liquids, and medicines that dissolve on the tongue or under the tongue.

As a shot (injection).

Usually medicine is injected under the skin between the skin and the muscle. Sometimes it is injected into a muscle.

Through a skin patch.

Medicine in the patch is absorbed through the skin.

As a nasal spray.

Medicine sprayed into the nose can be absorbed into the body quickly.

As a rectal suppository.

Medicine in capsules or pills is put inside the rectum and absorbed into the body.

With a needle into a vein (IV).

A person with an IV may be able to use a patient-controlled analgesia (PCA) pump. This lets you control your own pain medicines.

Into the spine.

Medicine can be put into the area around the spinal cord, such as with spinal anesthesia or an epidural.

With a pain pump.

Also called an infusion pump, this is placed under your skin to deliver pain medicine directly to your spine.

What are the side effects of pain medicines?

All medicines have side effects. They vary depending on which ones you take. Many side effects can be managed so that you can still take the medicine.

Talk to your doctor if you have any side effects. Your doctor may change your dose or the type of medicine you take.

Examples of side effects of over-the-counter medicines

Acetaminophen (Tylenol).

It may cause:

  • Nausea.
  • Rash.
  • Liver damage (with high doses).
Nonsteroidal anti-inflammatory drugs, or NSAIDs (such as Advil, Aleve, and Motrin).

These may cause:

  • Stomach upset and heartburn. If the medicine upsets your stomach, you can try taking it with food.
  • Stomach ulcers or kidney problems (with long-term use).
  • Allergic reaction (rare).
  • Increased risk of heart attack and stroke. These risks are greater if the medicine is taken at higher doses or for longer than recommended.

No one younger than 20 should take aspirin. It has been linked to Reye syndrome, a serious illness.

Examples of side effects of prescription medicines

Anticonvulsant medicines.

These may cause:

  • Dizziness.
  • Drowsiness.
  • Fatigue.
  • Headache.
  • Confusion.
  • Skin rash.
Opioid pain relievers.

They may cause:

  • Constipation.
  • Drowsiness.
  • Nausea or vomiting.
  • Trouble urinating.
  • Tolerance, or needing larger doses over time.

Opioid pain relievers can be misused. This can lead to developing opioid use disorder. Moderate to severe opioid use disorder is sometimes called addiction. Misusing opioids can also cause an accidental overdose or death. If you are worried about developing opioid use disorder, talk with your doctor.

Serotonin and norepinephrine reuptake inhibitor (SNRI) antidepressants.

These may cause:

  • Constipation or diarrhea.
  • Cough.
  • Dizziness.
  • Dry mouth.
  • Headache.
  • Nausea and loss of appetite.
  • Decrease in sexual desire or ability.
  • Sleep problems.
  • Weight gain or weight loss.
Tricyclic and tetracyclic antidepressants.

These may cause:

  • Blurred vision.
  • Constipation.
  • Weight gain.
  • Drowsiness and fatigue.
  • Dry mouth.
  • Loss of sexual desire or ability.
  • Abnormal heart rate.

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