Codeine – Uses, Side Effects, and More

Codeine is an opioid medication prescribed for mild to moderate pain and, in some cases, to control persistent coughing. While codeine can be a valuable tool in managing certain medical conditions, it’s important to understand that it carries risks. This medication can be habit-forming, and it is essential to take it only as prescribed by your doctor.

 

This article explains medical uses of codeine, its potential side effects, the risks associated with its use, and precautions you should be aware of before starting treatment. 

Uses

What is codeine prescribed for?

Codeine is an opioid analgesic indicated for the relief of mild to moderate pain [1]. It is also utilized as an antitussive to reduce the frequency and intensity of coughing. Your doctor might prescribe codeine for short-term pain management following a surgical procedure, dental work, or an injury.

 

In certain formulations, codeine is combined with other analgesics, such as acetaminophen or aspirin, to provide more effective pain relief. Due to the risk of dependence, codeine is typically recommended for short-term use. Follow your healthcare provider’s instructions to ensure the medication is used safely and appropriately.

How does codeine work?

Once absorbed, codeine is converted in the liver to morphine, which is its active form [2]. It then enters the bloodstream and travels to the central nervous system. In the brain and spinal cord, it binds to mu-opioid receptors on nerve cells. By binding to these receptors, codeine interferes with the transmission of pain signals from the body to the brain, thereby decreasing the sensation of pain. Its effect on the brainstem’s cough center also helps suppress the cough reflex.

How is codeine supplied?

Codeine is available in several formulations to suit different clinical needs. The most common form is an oral tablet, available in strengths of 15 mg, 30 mg, and 60 mg (as codeine sulfate)[3].

 

• 15 mg tablets: White, biconvex, scored, and imprinted with “15” on one side and “54 613” on the other.

• 30 mg tablets: White, biconvex, scored, and imprinted with “30” on one side and “54 783” on the other.

• 60 mg tablets: White, biconvex, scored, and imprinted with “60” on one side and “54 412” on the other.

 

Codeine is also available as an oral solution or syrup, often in combination with other medications for cough and cold symptoms. In a hospital setting, it may be administered as an injection by a healthcare professional.

How Should I Store Codeine?

To ensure its effectiveness and prevent misuse, codeine must be appropriately stored. Follow these guidelines:

 

• Store at Room Temperature: Keep the medication in a controlled room temperature environment, between 68°F and 77°F (20°C and 25°C). Avoid areas with extreme heat, moisture, and direct sunlight. For this reason, the bathroom cabinet is not a suitable storage location.

• Keep it Secure: Store codeine in a secure, lockable cabinet or box. Keep it out of reach of children, pets, and others to prevent misuse and accidental ingestion.

• Use Original Container: Always keep the medication in its original, labeled container with the child-resistant cap securely fastened.

• Proper Disposal: If the medication is no longer needed or has expired, dispose of it safely—do not throw it in the trash. Consult your pharmacist about local take-back programs or disposal instructions for controlled substances to prevent accidental exposure.

Side Effects

What are the common side effects of codeine?

Like any medication, codeine can cause side effects. The most frequently reported ones include [4]:

• Constipation: This is a very common side effect of opioids. It can begin shortly after starting the medication and may persist. Doctors advise patients to increase their fluid intake, consume more dietary fiber, and use an over-the-counter stool softener or laxative if necessary.

• Drowsiness and Dizziness: You may feel sleepy, lightheaded, or mentally “foggy,” especially when you first start taking codeine or if the dose is increased. Until you know how this medication affects you, you must avoid driving, operating heavy machinery, or performing any other hazardous activities.

• Nausea and Vomiting: This is also common but often improves after the first few days of treatment. Taking the medication with food may help lessen these symptoms.

 

Other less common side effects may include:

• Itching or mild rash

• Dry mouth

• Sweating

• Abdominal pain

• Urinary retention (difficulty urinating)

• Changes in mood

 

Long-term use of codeine, particularly at higher doses, increases the risk of physical dependence, tolerance, and withdrawal symptoms upon discontinuation.

 

What are the serious side effects of codeine?

While less common, some side effects of codeine are serious and require immediate medical attention. 

 

Serious side effects can include:

• Severe Respiratory Depression: This is the most serious risk. Signs include shallow, slow, or difficult breathing. This is a life-threatening emergency.

• Anaphylaxis (Severe Allergic Reaction): Symptoms can include swelling of the face, lips, tongue, or throat; severe hives; difficulty breathing or swallowing; and a feeling of tightness in the chest.

• Severe Dizziness, Fainting, or Loss of Consciousness: This could indicate a dangerous drop in blood pressure (hypotension).

• Seizures.

• Extreme drowsiness or inability to be awakened.

 

Some individuals are “ultra-rapid metabolizers” of codeine, meaning their bodies convert codeine to morphine very quickly. This can lead to dangerously high levels of morphine in the blood, increasing the risk of severe side effects, including life-threatening respiratory depression. For this reason, and due to safety concerns, the FDA has placed significant restrictions on the use of codeine in children [4].

Warnings & Precautions

As an opioid, codeine carries important warnings and requires careful consideration by both the prescribing physician and the patient.

 

Key precautions include:

• Respiratory Depression: Codeine can suppress the drive to breathe, which can be life-threatening. This risk is highest in elderly or debilitated patients and in those with pre-existing respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD), or sleep apnea.

• Serious Drug Interactions: Combining codeine with other central nervous system (CNS) depressants can lead to profound sedation, respiratory depression, coma, and death. These include alcohol, benzodiazepines (Xanax®, Valium®), sleep medications, and other opioids. Always inform your doctor of all medications, supplements, and substances you are taking.

• Dependence and Withdrawal: Prolonged use of codeine can lead to physical dependence. Abruptly stopping the medication after long-term use may cause withdrawal symptoms, including restlessness, muscle pain, nausea, and anxiety. Your doctor will provide a tapering schedule to discontinue the medication safely if needed.

• Hormonal Effects: Long-term opioid use can be associated with endocrine system effects, potentially leading to decreased libido, erectile dysfunction, or irregular menstrual cycles.

• Use in Pregnancy and Breastfeeding: Codeine is generally not recommended during pregnancy, as it can cross the placenta and may cause fetal harm or neonatal opioid withdrawal syndrome, a life-threatening condition for the newborn. It can also pass into breast milk and cause serious adverse reactions in a nursing infant.

Who should not use codeine (Contraindications)?

Codeine is contraindicated and should not be used in the following populations:

• Children under 12: Due to the risk of life-threatening respiratory depression.

• Post-Operative Children Under 18: Specifically after tonsillectomy and/or adenoidectomy, as these patients are particularly sensitive to respiratory depression.

• Patients with Significant Respiratory Depression: Including individuals with acute or severe bronchial asthma.

• Patients with Known or Suspected Gastrointestinal Obstruction: Including paralytic ileus.

• Individuals with a Known Hypersensitivity (Allergy): To codeine or any other ingredient in the formulation.

 

Opioids affect millions globally, including over 2 million in the U.S [5]. If you have a history of drug or alcohol problems, it’s best to avoid codeine due to its addictive nature. Pregnant women and individuals with digestive blockages, liver disease, or opioid allergies should also avoid it, as it can harm the baby or lead to withdrawal in newborns.

What Should I Know About Codeine Before Using It?

Your doctor can prescribe codeine after a complete understanding of your medical history. A thorough review helps prevent serious adverse effects and ensures this medication is appropriate for you.

 

Allergies

Tell your doctor about any allergic reactions you have had to codeine, other opioid medications (like morphine or hydrocodone), or any other drugs. You should also report any known allergies to foods, dyes, or preservatives.

 

Use in Children (Pediatric)

The use of codeine is contraindicated in children under 12 years of age. It should also not be used in patients 12 to 18 years of age who have undergone a tonsillectomy or adenoidectomy. In some children who are “ultra-rapid metabolizers,” codeine can be converted to morphine too quickly, leading to life-threatening respiratory depression and death.

 

Use in Older Adults (Geriatric)

Older adults are often more susceptible to the side effects of codeine, particularly confusion, sedation, dizziness, and respiratory depression. Patients with age-related decline in cardiac, hepatic, or renal function may require a reduced dosage and more careful monitoring.

 

Breastfeeding

Codeine is excreted into breast milk. A nursing infant can be exposed to high levels of morphine if the mother is an ultra-rapid metabolizer, potentially leading to serious and life-threatening adverse reactions in the infant, including excess sleepiness, difficulty breastfeeding, and severe breathing problems. It is strongly recommended to avoid codeine while breastfeeding [6]. 

 

Drug and Substance Interactions

You must provide a list of all medications you are currently taking, including prescriptions, over-the-counter drugs, and herbal supplements. Interactions with codeine can be dangerous.

 

Of particular concern is the concurrent use of codeine with other Central Nervous System (CNS) depressants. Combining these substances significantly increases your risk of profound sedation, severe respiratory depression, coma, and death. 

 

Be sure to tell the doctor if you use any of the following:

• Other opioids

• Benzodiazepines or other anti-anxiety medications (Xanax®, Ativan®, Valium®)

• Sedatives, hypnotics, or sleep aids

• Allergy or cold medicines

• Antipsychotic medications

• Muscle relaxants

• Alcohol

Interactions

Codeine can interact with many other medications, increasing the risk of serious side effects. Taking it with other opioids, sedatives, sleep aids, anti-anxiety drugs, or alcohol can cause dangerous drowsiness, breathing problems, or even coma. Certain antidepressants and antipsychotics may also raise these risks. Some drugs can affect how your body breaks down codeine, leading to higher or unpredictable levels in your system. 

 

Always tell your doctor about all prescription drugs, over-the-counter medicines, vitamins, or herbal products you use. This helps prevent harmful interactions and ensures codeine is used as safely as possible. Never start or stop medication without your doctor’s advice.

Does Codeine Interact with Foods or Drinks?

Yes, codeine can interact with certain drinks, especially alcohol. Drinking alcohol while taking codeine greatly increases the risk of dangerous drowsiness, slow breathing, difficult breathing, and even death [7]. Grapefruit juice may also affect how your body processes codeine, possibly raising side effects. It’s best to avoid alcohol altogether and talk to your doctor about grapefruit or other foods that could interfere with how codeine works in your body.

Does Codeine Interact with Other Medicines (Drug Interactions)?

Yes, codeine can interact with many medicines, like other opioids, sedatives, antidepressants, or anti-anxiety drugs. These combinations may increase drowsiness, slow breathing, or cause serious side effects. Always tell your doctor about all the medications and supplements you take to avoid dangerous interactions with codeine.

Overdose / Missed Dose

What should I do in case of an overdose?

An overdose of codeine is a medical emergency that requires immediate attention. Taking too much codeine can be fatal.

Seek emergency medical care immediately if you or someone else has taken more than the prescribed amount.

 

Signs and symptoms of a codeine overdose include:

• Extreme drowsiness or inability to be awakened (stupor)

• Slow, shallow, or stopped breathing

• Pinpoint pupils

• Cold, clammy skin

• Limp muscles

• Loss of consciousness or coma

What should I do if I miss a dose?

If you miss a dose of codeine, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule.

 

Do not take two doses at once or take extra medication to make up for the missed dose. Doubling the dose will increase your risk of experiencing adverse side effects. If you are unsure what to do, contact your pharmacist for guidance.

FAQs

What is codeine sulfate used for?

Codeine sulfate is an opioid medicine used to relieve mild to moderate pain and to control a bad cough. It changes how the brain and nervous system process pain and coughing. Doctors usually prescribe it for a short time after surgeries or injuries when other pain relievers are not enough.

 

Is codeine sulfate the same as morphine?

Codeine and morphine are related but not the same. Codeine needs to be processed by your liver to work, converting it into several substances, including some morphine, which provides pain relief. Morphine is a stronger opioid often used for severe pain. The effects of codeine can vary from person to person.

 

Is codeine sulfate stronger than hydrocodone?

Codeine sulfate is a weaker opioid than hydrocodone. Hydrocodone offers stronger pain relief, so doctors typically prescribe it for moderate to moderately severe pain that codeine cannot manage effectively.

 

Is codeine considered a strong opioid?

Codeine is a weaker opioid used for mild to moderate pain. It has risks like dependence, misuse, and serious side effects. Always use codeine as prescribed by a doctor.

Get Help for Codeine or Opioid Misuse at Alliance Recovery

If you’re facing codeine dependence or concerns about opioid use, professional support is ready to help. At Alliance Recovery, our dedicated team can guide you toward lasting recovery with a proven track record in addiction treatment.

 

When you come to Alliance Recovery, you’ll receive:

• Personalized individual and group therapy to meet your needs.

• A caring, sober community that truly gets what you’re going through.

• Strong aftercare planning and resources to rebuild your life and career.

Call our team today at (844) 287-8506 to start your recovery journey.

Sources:

[1] https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/codeine-information

[2] https://nida.nih.gov/research-topics/opioids#work

[3] https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/022402s006lbl.pdf

[4] https://www.ncbi.nlm.nih.gov/books/NBK526029/#article-19677.s5

[5] https://www.ncbi.nlm.nih.gov/books/NBK553166/

[6] https://medlineplus.gov/druginfo/meds/a601005.html?

[7] https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-fda-warns-about-serious-risks-and-death-when-combining-opioid-pain-or