Morphine extended-release oral tablet side effects: A detailed guide

This article describes possible side effects of morphine extended-release (ER) oral tablet. (With ER, the drug releases slowly over time in your body.) You’ll also find information on cost savings and coupon options for morphine. You can explore this overview article to learn more about morphine ER oral tablet, including the drug’s uses, side effects, ways to save on cost, and more.

Morphine ER oral tablet is a generic version of the brand-name drug MS Contin. Morphine also comes in other forms, including injectable forms and other forms that you’ll swallow, but these forms aren’t described in this article. To learn more about these forms, talk with your doctor.

Boxed warnings

Morphine has boxed warnings about the following risks. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

• risk of misuse and addiction
• risk of serious respiratory depression
• risk of accidental ingestion
• risk of neonatal opioid withdrawal syndrome (NOWS)
• risk of serious harm if taken with benzodiazepines or other central nervous system depressants

For details about the risk of misuse and addiction, see the “Misuse and morphine” section below. For more information about the risk of NOWS, see the “Warnings for morphine” section below. For details about all the other risks, see the “Side effects of morphine in detail” section below.

More common side effects of morphine

Morphine extended-release (ER) oral tablet may cause mild or serious side effects. Below are some of the more common side effects of this medication.

Commonly reported side effects of morphine ER oral tablet include:

• constipation
• dizziness
• sleepiness
• nausea
• vomiting

Mild side effects of morphine

Morphine may cause certain mild side effects. Most often, mild side effects are temporary and can be easily managed. Tell your doctor or pharmacist if you have side effects that don’t go away or become bothersome.

Mild side effects of morphine extended-release (ER) oral tablet that occurred in studies include:

• constipation or diarrhea
• dizziness
• sleepiness
• nausea
• vomiting
• sweating
• feeling uneasy
• dry mouth
• abdominal pain
• indigestion (upset stomach)
• weakness
• decreased appetite
• decreased libido (sex drive)
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)
• swelling, such as in the legs or ankles
• mild allergic reaction*

* To learn more about this side effect, see the “Side effects of morphine in detail” section below.

Morphine ER oral tablet may cause more mild side effects than those listed above. For details, see the drug’s prescribing information.

Serious side effects of morphine

Morphine may cause certain serious side effects. If you have any serious side effects from morphine extended-release (ER) oral tablet, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.

After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with morphine.

Serious side effects of morphine ER oral tablet that occurred in studies include:

• adrenal insufficiency (inability of your adrenal glands to make enough hormones)
• bladder problems, including urinary retention
• hallucinations
• heart problems, including irregular heart rhythm and high blood pressure
• mood and mental health problems, including depression
• seizure
• very low blood pressure, including when standing or sitting up, which may lead to fainting
• vision problems, including blurry or double vision
• withdrawal symptoms, including suicidal thoughts, if you suddenly stop taking the drug
• central nervous system (CNS) depression*
• risk of misuse and addiction†
• risk of serious respiratory depression‡
• risk of accidental ingestion‡
• risk of serious harm if taken with benzodiazepines or other CNS depressants‡
• risk of neonatal opioid withdrawal syndrome§
• severe allergic reaction*

* To learn more about this side effect, see the “Side effects of morphine in detail” section below.
† Morphine ER oral tablet has a boxed warning for this side effect. A boxed warning is the most serious warning from the FDA. To learn more, see the “Misuse and morphine” section below.
‡ Morphine ER oral tablet has a boxed warning for this side effect. A boxed warning is the most serious warning from the FDA. To learn more, see the “Side effects of morphine in detail” section below.
§ Morphine ER oral tablet has a boxed warning for this side effect. A boxed warning is the most serious warning from the FDA. To learn more, see the “Warnings for morphine” section below.

Suicide prevention

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

• Call the 988 Suicide and Crisis Lifeline at 988.
• Text HOME to the Crisis Textline at 741741.
• Not in the United States? Find a helpline in your country with Befrienders Worldwide.
• Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you are not in the same household, stay on the phone with them until help arrives.

Common questions about side effects of morphine

Here are answers to some common questions about side effects of morphine extended-release (ER) oral tablet. If you have other questions, talk with your doctor or pharmacist.

Is morphine safe for older adults?

Yes, morphine is safe for use in older adults (age 65 years and older).

That said, doctors sometimes prescribe a lower starting dose of morphine to older adults. They may also wait longer before increasing the dose if needed. This is because as you age, your organs, including your liver and kidneys, don’t work as they used to. And having a liver or kidney condition can affect whether morphine is safe for you to take.

Talk with your doctor to learn more about the risks and benefits of treatment with morphine. This includes how your health history affects your risk of side effects if you take the drug.

Does morphine cause long-term side effects?

Yes, in some cases, morphine ER oral tablet may cause long-term side effects. These can occur if you take the drug for a long time.

Examples of long-term side effects reported with morphine ER oral tablet include:

• adrenal insufficiency (inability of your adrenal glands to make enough hormones)
• risk of misuse and addiction*
• risk of serious respiratory depression†

Talk with your doctor to learn more about these side effects and how to manage them. Ask your doctor for more information about how long these side effects of morphine may last.

* Morphine ER oral tablet has a boxed warning for this side effect. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Misuse and morphine” section below.
† Morphine ER oral tablet has a boxed warning for this side effect. A boxed warning is the most serious warning from the FDA. To learn more, see the “Side effects of morphine in detail” section below.

Misuse and morphine

Morphine extended-release (ER) oral tablet has a boxed warning about the risk of misuse and addiction. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

Like other opioid drugs, morphine ER oral tablet has a risk of misuse. Misuse is when a drug is taken in a way other than how it’s prescribed, such as taking it to feel “high.” Misusing morphine ER oral tablet can cause life threatening side effects, including an overdose.

Misusing morphine can also lead to addiction. With drug addiction, you continue taking a drug despite it causing harm.

Due to these risks, morphine ER oral tablet is a controlled substance in the United States. Healthcare professionals must follow strict laws whenever they prescribe or dispense morphine ER oral tablet. These laws are in place to help prevent misuse and addiction.

Before prescribing morphine ER oral tablet, your doctor will ask about your health history. This includes asking if you have a substance use disorder, such as opioid use disorder. This will help your doctor determine whether morphine ER oral tablet is safe for you to take.

Talk with your doctor if you have questions or concerns about morphine ER oral tablet and misuse or addiction.

Coupon for morphine

Visit this page to access Optum Perks coupons and get price estimates for morphine when you use the coupons. These coupons can provide significant savings on your prescription costs. 

Note: Optum Perks coupons cannot be used with insurance copays or benefits.

Side effects of morphine in detail

Below you’ll find details on some of the side effects of morphine extended-release (ER) oral tablet.

Boxed warnings

Morphine ER oral tablet has boxed warnings about the following risks:

• risk of serious respiratory depression
• risk of accidental ingestion
• risk of serious harm if taken with benzodiazepines or other central nervous system depressants

A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

Risk of serious respiratory depression

With respiratory depression, you experience slow, shallow breathing or difficulty breathing. In rare cases, such as with overdose, you may stop breathing. This side effect was rare in studies of morphine ER oral tablet.

The risk of this side effect is highest when you first start taking morphine ER oral tablet and any time your dose is increased. But it can occur at any time during treatment. If you have sleep apnea or another breathing condition, you have a higher risk of this side effect.

Ways to manage

If you believe you’re having symptoms of respiratory depression from taking morphine ER oral tablet, seek emergency medical attention, such as calling 911 or your local emergency number.

If you’re prescribed morphine ER oral tablet, your doctor may also prescribe naloxone. It’s an emergency treatment that treats respiratory depression from taking too much morphine.

Risk of accidental ingestion

If morphine ER oral tablet is accidentally taken by someone it’s not prescribed to, such as a child, it can be life threatening with only one dose. Children have a higher risk of accidental ingestion and serious side effects of morphine.

Ways to manage

If someone accidentally ingests morphine ER oral tablet, seek emergency medical attention. You can call 911 or your local emergency number.

To help prevent accidental ingestion, keep morphine ER oral tablet stored somewhere safe and out of reach from children.

Risk of serious harm if taken with benzodiazepines or other central nervous system depressants

Serious harm can occur if morphine ER oral tablet is taken with benzodiazepines or other central nervous system (CNS) depressants.

On its own, morphine ER can cause CNS depression as a side effect. Taking it with a benzodiazepine or another CNS depressant raises the risk and severity of this side effect. And serious CNS depression can be life threatening in rare cases.

Examples of benzodiazepines include alprazolam (Xanax) and clonazepam (Klonopin). Other CNS depressants include sleep drugs such as zolpidem (Ambien) and muscle relaxants like methocarbamol (Robaxin).

Ways to manage

Because of this risk, doctors try to avoid prescribing morphine ER oral tablet with benzodiazepines or other CNS depressants. If there are no other treatment options, your doctor will prescribe the lowest dose of morphine and the other drug for the shortest time needed to treat your condition.

If you have concerns about these risks, tell your doctor. They can review the risks and benefits of morphine ER tablet and decide the best treatment for your pain.

Central nervous system (CNS) depression

In studies, CNS depression was rare in people taking morphine ER oral tablet. This side effect may be mild or serious.

With CNS depression, your CNS function slows down. (Your CNS is made up of your brain and spinal cord). Symptoms may include severe problems with balance or coordination or slurred speech. This can affect your ability to safely perform certain activities, such as driving or operating machinery. You may also have difficult or slowed breathing or even coma in serious cases.

Certain factors can raise the risk of CNS depression with morphine ER oral tablet. These include taking other medications that cause CNS depression, such as eszopiclone (Lunesta), zolpidem (Ambien), or methocarbamol (Robaxin).

Ways to manage

If your symptoms feel severe or life threatening, seek immediate medical treatment. You can call 911 or your local emergency number or go to the nearest hospital.

If you experience mild symptoms of CNS depression, tell your doctor. They’ll likely recommend lowering your morphine dose or stopping treatment.

Allergic reaction

For some people, morphine ER oral tablet can cause an allergic reaction. These reactions were rare in studies.

Symptoms can be mild or serious, and they may include:

• itchiness
• skin rash
• swelling under the skin, usually affecting eyelids, lips, hands, or feet
• swelling of the mouth, tongue, or throat, which can make it hard to breathe
• flushing (temporary warmth, redness, or deepening of skin color)

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to morphine ER oral tablet, your doctor may recommend taking a different medication instead.

Warnings for morphine

Below are some factors you may want to discuss with your doctor before taking morphine extended-release (ER) oral tablet.

Boxed warnings

This drug has boxed warnings about the following risks. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

• risk of misuse and addiction
• risk of serious respiratory depression
• risk of accidental ingestion
• risk of neonatal opioid withdrawal syndrome (NOWS)
• risk of serious harm if taken with benzodiazepines or other central nervous system depressants

For details about the risk of misuse and addiction, see the “Misuse and morphine” section above. For more information about the risk of NOWS, see the “Morphine and pregnancy” section below. For details about all the other risks, see the “Side effects of morphine in detail” section above.

Other warnings

It may not be safe for you to take morphine ER oral tablet if you have specific health conditions. These are sometimes called drug-condition interactions. Other things may also affect whether morphine ER oral tablet is a safe treatment option for you.

Before taking morphine ER oral tablet, tell your doctor about your health and medications you take. Things to consider include:

• breathing or lung conditions, such as chronic obstructive pulmonary disease
• blockage or narrowing in your bowels or stomach
• epilepsy or seizures
• head injury
• thyroid conditions
• liver conditions
• pancreas conditions
• gallbladder conditions
• kidney conditions
• urinary conditions
• past allergic reaction to morphine

Morphine and pregnancy

Morphine ER oral tablet has a boxed warning for the risk of neonatal opioid withdrawal syndrome (NOWS) if taken during pregnancy. A boxed warning is the most serious warning from the FDA.

Risk of neonatal opioid withdrawal syndrome

If morphine is taken for a long time during pregnancy, it could cause NOWS. With NOWS, an infant experiences opioid withdrawal symptoms after birth. Withdrawal symptoms are side effects that happen when you stop taking a drug your body is dependent on. This can happen with infants because they are no longer exposed to morphine following birth. Without immediate treatment, opioid withdrawal in an infant can be life threatening.

If you’re pregnant or can become pregnant, talk with your doctor about treatment options for your pain. They can review the risks and benefits of morphine ER oral tablet and other pain treatments when taken during pregnancy. If you agree that you’ll take the drug during pregnancy, your doctor can monitor your child after delivery. And they can treat NOWS if it occurs.

Morphine and breastfeeding

Morphine ER oral tablet should not be taken while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking this medication. Your doctor may recommend other ways to feed your child during treatment with morphine.

Morphine and alcohol

Morphine ER oral tablet is known to interact with alcohol. You should avoid consuming alcohol while you’re taking morphine ER oral tablet.

Both morphine ER oral tablet and alcohol can cause central nervous system (CNS) depression. Combining the two further raises the severity and risk of this side effect. Serious CNS depression can result in life threatening side effects, such as respiratory depression (shallow, slow, or stopped breathing).

Talk with your doctor if you have more questions about the risks of consuming alcohol while you’re taking morphine ER oral tablet.

What to ask your doctor

This article describes common and serious side effects of morphine extended-release (ER) oral tablet. If your doctor prescribes this medication, they can discuss possible side effects with you. Let your doctor know if you have concerns or questions about treatment with this medication.

Here’s a list of some possible questions you may want to ask your doctor:

• How do side effects of morphine ER oral tablet compare with other treatments for severe pain?
• Do any health conditions I have interact with morphine ER oral tablet and raise my risk of side effects from taking it?
• If any medications I take interact with morphine ER oral tablet, will you prescribe a lower dose for me to take?
• How long do side effects of morphine ER oral tablet typically last?

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.