Codeine / Phenylephrine / Promethazine Side Effects

Medically reviewed by Drugs.com. Last updated on Sep 8, 2024.

Applies to codeine / phenylephrine / promethazine: oral elixir, oral syrup.

Precautions

It is very important that your doctor check your or your child's progress while using this medicine. This will allow your doctor to see if the medicine is working properly and to decide if you or your child should continue to take it. Blood tests may be needed to check for unwanted effects.

If your or your child's symptoms (eg, cough) do not improve or become worse within 5 days, check with your doctor right away.

Do not use this medicine if you or your child is using or has used an MAO inhibitor (MAOI) such as isocarboxazid [Marplan®], linezolid [Zyvox®], phenelzine [Nardil®], selegiline [Eldepryl®], tranylcypromine [Parnate®]) within the past 14 days.

Codeine is changed to morphine in the body. Some people change codeine to morphine more quickly than others. These individuals are called "ultra-rapid metabolizers of codeine". Contact your doctor immediately if you have extreme drowsiness, sleepiness, confusion, or shallow breathing. These symptoms may indicate that you are an "ultra-rapid metabolizer of codeine". As a result, there is too much morphine in the body and more side effects of morphine than usual. Children may be especially sensitive to this effect. Do not give this medicine to:

• Children younger than 12 years of age.
• Children younger than 18 years of age who have had surgery removal of tonsils or adenoids.
• Children 12 to 18 years of age who have a high risk for breathing problems (eg, obstructive sleep apnea, obesity, lung disease).

If a nursing mother is an ultra-rapid metabolizer of codeine, it could lead to morphine overdose in the nursing baby and cause very serious side effects.

For nursing mothers taking this medicine:

• Talk to your doctor if you have any questions about using codeine or about how this medicine may affect your baby.
• Call your doctor if you become extremely tired and have difficulty caring for your baby.
• Your baby should generally nurse every 2 to 3 hours and should not sleep for more than 4 hours at a time.
• Check with your doctor, hospital emergency room, or local emergency services (eg, "call 9-1-1") immediately if your baby shows signs of increased sleepiness (more than usual), difficulty breastfeeding, difficulty breathing, or limpness. These may be symptoms of an overdose and need immediate medical attention.

Using this medicine while you are pregnant may cause serious unwanted effects, including neonatal opioid withdrawal syndrome in your newborn baby. Tell your doctor right away if you think you are pregnant or if you plan to become pregnant while using this medicine.

If you think you or someone else may have taken an overdose of this medicine, get emergency help at once. Signs of an overdose include: dark urine, difficult or troubled breathing, irregular, fast or slow, or shallow breathing, nausea, vomiting, pain in the upper stomach, pale or blue lips, fingernails, or skin, pinpoint pupils of the eyes, or yellow eyes or skin.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that can make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicine, other prescription pain medicine or narcotics, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor before taking any of these medicines while you or your child are using this medicine.

This medicine may be habit-forming. If you feel that the medicine is not working as well, do not use more than your prescribed dose. Call your doctor for instructions.

Using narcotics for a long time can cause severe constipation. To prevent this, your doctor may direct you to take laxatives or stool softeners, drink a lot of fluids, or increase the amount of fiber in your diet. Be sure to follow the directions carefully, because continuing constipation can lead to more serious problems.

This medicine may make you dizzy, drowsy, or less alert than they are normally. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

Dizziness, lightheadedness, or fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help. Also, lying down for a while may relieve dizziness or lightheadedness.

Promethazine may increase your risk for convulsions (seizures). It may also cause dystonia (movement disorder). This is more likely in sick children with diarrhea. Talk to your doctor if you have any concerns.

Check with your doctor right away if you or your child are having convulsions, difficulty with breathing, fast heartbeat, high fever, high or low blood pressure, increased sweating, loss of bladder control, severe muscle stiffness, unusually pale skin, or tiredness. These could be symptoms of a serious condition called neuroleptic malignant syndrome (NMS).

This medicine may cause adrenal insufficiency. Check with your doctor right away if you have darkening of the skin, diarrhea, dizziness, fainting, loss of appetite, mental depression, nausea, skin rash, unusual tiredness or weakness, or vomiting.

If you are especially sensitive to the effects of this medicine, do not suddenly stop using it without first checking with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely. This may help reduce the possibility of withdrawal symptoms, such as abdominal or stomach cramps, anxiety, fever, nausea, runny nose, sweating, tremors, or trouble sleeping.

Using too much of this medicine may cause infertility (unable to have children). Talk with your doctor before using this medicine if you plan to have children.

Make sure any doctor or dentist who treats you knows that you are using this medicine. You or your child may need to stop using this medicine several days before you have surgery or medical tests.

This medicine may make your skin more sensitive to sunlight. Use sunscreen when you are outdoors. Avoid sunlamps and tanning beds.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Other side effects

Some side effects of codeine / phenylephrine / promethazine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Serious side effects

Along with its needed effects, codeine/phenylephrine/promethazine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking codeine / phenylephrine / promethazine:

For healthcare professionals

Applies to codeine / phenylephrine / promethazine: oral syrup.

General adverse events

The more commonly reported adverse effects have included nausea, vomiting, constipation, blurred vision, confusion, and dizziness.^[Ref]

Respiratory

Codeine:

• Frequency not reported: Respiratory depression

Phenylephrine:

• Frequency not reported: Respiratory distress

Promethazine:

• Frequency not reported: Asthma, nasal stuffiness, respiratory depression, apnea^[Ref]

Concomitant administration of promethazine with other respiratory depressants has been associated with respiratory depression, including fatalities. Postmarketing cases in pediatric patients less than 2 years of age has been reported with a wide range of weight-based doses. Respiratory depression has been associated with antitussive use of codeine in young children.

Respiratory depression and death have occurred in children who received codeine in the postoperative period following tonsillectomy and/or adenoidectomy. Further investigation has shown these patients to be ultra-rapid metabolizers of codeine. Children with obstructive sleep apnea who are treated with codeine appear to be particularly sensitive to the respiratory depressant effects of codeine.^[Ref]

Cardiovascular

Codeine:

• Frequency not reported: Tachycardia, bradycardia, palpitation, faintness, syncope, orthostatic hypotension, circulatory depression

Phenylephrine:

• Frequency not reported: Ischemia

Promethazine:

• Frequency not reported: Increased or decreased blood pressure, tachycardia,

bradycardia, faintness^[Ref]

Ischemia with risk of gangrene or thrombosis of compromised vascular may result with phenylephrine use.^[Ref]

Nervous system

Codeine:

• Frequency not reported: CNS depression, lightheadedness, dizziness, sedation, headache, convulsions, weakness

Phenylephrine:

• Frequency not reported: Restlessness, dizziness, tremor, weakness

Promethazine:

• Frequency not reported: Drowsiness, sedation, somnolence, extra-pyramidal symptoms, torticollis, tongue protrusion, incoordination, tremors, seizures, neuroleptic malignant syndrome, paradoxical reactions^[Ref]

Promethazine use has resulted in paradoxical reactions described as hyperexcitability and abnormal movements. This has occurred following 1 dose and in some patients accompanied by respiratory depression, nightmares, delirium, and agitated behavior.^[Ref]

Psychiatric

Codeine:

• Frequency not reported: Euphoria, dysphoria, transient hallucination, disorientation

Phenylephrine:

• Frequency not reported: Anxiety, nervousness

Promethazine:

• Frequency not reported: Confusion, disorientation, euphoria, nervousness, insomnia, excitation, catatonic-like states, hysteria, hallucinations^[Ref]

Gastrointestinal

Codeine:

• Frequency not reported: Nausea, vomiting, constipation, biliary tract spasm, increased colonic motility, toxic dilation

Patients with chronic ulcerative colitis may experience increased colonic motility, while patients with acute ulcerative colitis have experienced toxic dilation with codeine use.

Promethazine:

• Frequency not reported: Dry mouth, nausea, vomiting^[Ref]

Hypersensitivity

Codeine:

• Frequency not reported: Pruritus, giant urticaria, angioneurotic edema, laryngeal edema

Promethazine:

• Frequency not reported: Angioneurotic edema

Sodium Metabisulfite:

• Frequency not reported: Anaphylaxis^[Ref]

The syrup contains sodium metabisulfite, a sulfite that may cause allergic-type reactions in susceptible people. Allergic type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes are possible.^[Ref]

Other

Phenylephrine:

• Frequency not reported: Pain

Promethazine:

• Frequency not reported: Lassitude, tinnitus, fatigue^[Ref]

Genitourinary

Codeine:

• Frequency not reported: Oliguria, urinary retention, antidiuretic effect^[Ref]

Dermatologic

Promethazine:

• Frequency not reported: Dermatitis, photosensitivity, urticaria^[Ref]

Hematologic

Promethazine:

• Frequency not reported: Leukopenia, thrombocytopenia, thrombocytopenic purpura, agranulocytosis^[Ref]

Hepatic

Promethazine:

• Frequency not reported: Cholestatic jaundice^[Ref]

Metabolic

Promethazine:

• Frequency not reported: Hyperglycemia^[Ref]

Ocular

Codeine:

• Frequency not reported: Visual disturbances

Promethazine:

• Frequency not reported: Blurred vision, oculogyric crisis, diplopia^[Ref]

See also:

Further information

Codeine/phenylephrine/promethazine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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