Phrenilin With Caffeine And Codeine Side Effects

Generic name: acetaminophen / butalbital / caffeine / codeine

Medically reviewed by Drugs.com. Last updated on Jan 4, 2025.

Note: This document provides detailed information about Phrenilin with Caffeine and Codeine Side Effects associated with acetaminophen / butalbital / caffeine / codeine. Some dosage forms listed on this page may not apply specifically to the brand name Phrenilin with Caffeine and Codeine.

Applies to acetaminophen / butalbital / caffeine / codeine: oral capsule.

Precautions

It is very important that your doctor check your progress while you are using this medicine, especially within the first 24 to 72 hours of treatment. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood and urine tests may be needed to check for unwanted effects.

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

If you think you or someone else may have taken an overdose of this medicine, get emergency help at once. Your doctor may also give naloxone and other medicines to treat an overdose.Signs of an overdose include: dark urine, difficult or trouble breathing, irregular, fast or slow, or shallow breathing, nausea or 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 may cause sleep-related breathing problems (eg, sleep apnea, sleep-related hypoxemia). Your doctor may decrease your dose if you have sleep apnea (stop breathing for short periods during sleep) while using this medicine.

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. Also, there may be a greater risk of liver damage if you drink 3 or more alcoholic beverages while you are taking acetaminophen. Do not drink alcoholic beverages, and check with your doctor before taking any of these medicines while you are using this medicine.

This medicine may cause adrenal gland problems. 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.

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. If this problem continues or gets worse, check with your doctor right away.

This medicine may make you dizzy, drowsy, confused, or disoriented. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

This medicine may cause serious skin reactions (eg, acute generalized exanthematous pustulosis, Stevens-Johnson syndrome, toxic epidermal necrolysis). Check with your doctor right away if you have blistering, peeling, or loosening of the skin, chills, cough, diarrhea, itching, joint or muscle pain, red irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in the mouth or on the lips, or unusual tiredness or weakness.

This medicine may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and require immediate medical attention. Call your doctor right away if you have a cough, dizziness, fast heartbeat, hives, rash, itching, puffiness or swelling of the eyelids, or around the eyes, face, lips, or tongue, tightness in the chest, trouble breathing or swallowing, or unusual tiredness or weakness while you are using this medicine.

Check the labels of all nonprescription (over-the-counter [OTC]) or prescription medicines you now take. If any contain a barbiturate, acetaminophen, caffeine, or codeine, check with your doctor. Taking them together with this medicine may cause an overdose.

Using this medicine while you are pregnant may cause serious unwanted effects, including neonatal 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.

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 experience extreme 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 a 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 taking 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 or hospital emergency room right away 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.

Do not suddenly Stop taking acetaminophen/butalbital/caffeine/codeine without first checking with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping completely. This may help prevent a possible worsening of your condition and reduce the possibility of withdrawal symptoms such as restlessness, chills, muscle pain, runny nose, sweating, tearing of the eyes, or yawning.

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, 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.

Before you have any medical tests, tell the medical doctor in charge that you are taking this medicine. The results of some tests may be affected by this medicine.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking this medicine. Serious side effects can occur if your doctor or dentist gives you certain medicines without knowing that you have been taking butalbital or codeine.

Check with your doctor right away if you have anxiety, restlessness, a fast heartbeat, fever, sweating, muscle spasms, twitching, nausea, vomiting, diarrhea, or see or hear things that are not there. These may be symptoms of a serious condition called serotonin syndrome. Your risk may be higher if you also take certain other medicines that affect serotonin levels in your body.

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.

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 acetaminophen / butalbital / caffeine / codeine 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, acetaminophen/butalbital/caffeine/codeine 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 acetaminophen / butalbital / caffeine / codeine:

Get emergency help immediately if any of the following symptoms of overdose occur while taking acetaminophen / butalbital / caffeine / codeine:

Symptoms of overdose

• anxiety (severe)
• cold and clammy skin
• confusion (severe)
• dizziness, lightheadedness, drowsiness, or weakness (severe)
• excitement (severe)
• increased sleepiness in babies (more than usual)
• increased sweating
• irritability (severe)
• limpness (in babies)
• nausea
• restlessness (severe)
• slow, fast, or irregular heartbeat
• slurred speech
• stomach cramps or pain
• swelling, pain, or tenderness in the upper abdomen or stomach area
• trembling or shaking of the hands or feet
• trouble sleeping (severe)
• unusually slow breathing
• vomiting

For healthcare professionals

Applies to acetaminophen / butalbital / caffeine / codeine: oral capsule.

General adverse events

The most frequently reported adverse events have included drowsiness, lightheadedness, dizziness, sedation, shortness of breath, nausea, vomiting, abdominal pain, and intoxicated feeling.^[Ref]

Hepatic

Acetaminophen:

• Frequency not reported: Liver failure^[Ref]

Acute liver failure has been reported with acetaminophen use; many cases have been associated with use at doses in excess of 4 g/day, and often involving more than 1 acetaminophen-containing product.^[Ref]

Respiratory

• Common (1% to 10%): Shortness of breath
• Uncommon (0.1% to 1%): Nasal congestion

Codeine:

• Postmarketing reports: Respiratory depression including deaths^[Ref]

Respiratory depression resulting in death has been reported in children who received codeine postoperatively following tonsillectomy and/or adenoidectomy. These children had evidence of being ultra-rapid metabolizers of codeine. Death has also been reported in nursing infants exposed to high levels of morphine in breast milk due to their breastfeeding mother being an ultra-rapid metabolizer of codeine.^[Ref]

Hypersensitivity

• Uncommon (0.1% to 1%): Allergic reactions
• Postmarketing reports: Anaphylaxis

Acetaminophen:

• Postmarketing reports: Anaphylaxis^[Ref]

Dermatologic

Butalbital/Acetaminophen/Caffeine/Codeine:

• Uncommon (0.1% to 1%): Hyperhidrosis, pruritus
• Frequency not reported: Toxic epidermal necrolysis, erythema multiforme

Acetaminophen:

• Rare (less than 0.1%): Serious skin reactions such as acute generalized exanthematous pustulosis, Stevens-Johnson syndrome, and toxic epidermal necrolysis
• Frequency not reported: Rash^[Ref]

Several cases of dermatologic reactions including toxic epidermal necrolysis and erythema multiforme have been reported with butalbital/acetaminophen/caffeine.^[Ref]

Psychiatric

Butalbital/Acetaminophen/Caffeine/Codeine:

• Uncommon (0.1% to 1%): Agitation, euphoria

Caffeine:

• Frequency not reported: Irritability, dependence^[Ref]

Gastrointestinal

• Common (1% to 10%): Nausea, vomiting, abdominal pain
• Uncommon (0.1% to 1%): Dry mouth, difficulty swallowing, heartburn, flatulence, constipation^[Ref]

Renal

Butalbital/Acetaminophen/Caffeine/Codeine:

• Uncommon (0.1% to 1%): Diuresis

Caffeine:

• Frequency not reported: Nephrotoxicity^[Ref]

Hematologic

Acetaminophen:

• Frequency not reported: Thrombocytopenia, agranulocytosis^[Ref]

Cardiovascular

Butalbital/Acetaminophen/Caffeine/Codeine:

• Uncommon (0.1% to 1%): Tachycardia

Caffeine:

• Frequency not reported: Cardiac stimulation^[Ref]

Nervous system

Butalbital/Acetaminophen/Caffeine/Codeine:

• Common (1% to 10%): Drowsiness, lightheadedness, dizziness, sedation
• Uncommon (0.1% to 1%): Headache, shaky feeling, tingly, fainting, numbness, seizures, mental confusion, excitement or depression due to intolerance

Caffeine:

• Frequency not reported: Tremor

Opioids:

• Frequency not reported: Serotonin syndrome (with concomitant serotonergic drugs)^[Ref]

Other

• Common (1% to 10%): Intoxicated feeling
• Uncommon (0.1% to 1%): Fatigue, high energy, heavy eyelids, sluggishness, hot spells, fever, earache, tinnitus

Metabolic

Caffeine:

• Frequency not reported: Hyperglycemia^[Ref]

Musculoskeletal

• Uncommon (0.1% to 1%): Leg pain, muscle fatigue^[Ref]

Endocrine

Opioids:

• Frequency not reported: Adrenal insufficiency, androgen deficiency

See also:

Further information

Phrenilin with Caffeine and Codeine 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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