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Trezix Side Effects

Generic Name: acetaminophen / caffeine / dihydrocodeine

Note: This document contains side effect information about acetaminophen / caffeine / dihydrocodeine. Some of the dosage forms listed on this page may not apply to the brand name Trezix.

For the Consumer

Applies to acetaminophen / caffeine / dihydrocodeine: oral capsule, oral tablet

Along with its needed effects, acetaminophen/caffeine/dihydrocodeine 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/caffeine/dihydrocodeine:

More common
  • Bleeding gums
  • blood in the urine or stools
  • bloody, black, or tarry stools
  • chest pain
  • chills
  • clay colored stools
  • cough
  • dark urine
  • decreased appetite
  • dizziness
  • drowsiness
  • fever
  • headache
  • high fever
  • itching or skin rash
  • lightheadedness
  • loss of appetite
  • nausea
  • painful or difficult urination
  • pale skin
  • pinpoint red spots on the skin
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • stomach pain or tenderness
  • swelling of the feet or lower legs
  • swollen glands
  • unexplained or unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting
  • yellow eyes or skin
  • Agitation
  • confusion
  • decreased urine output
  • difficulty with swallowing
  • fast heartbeat
  • hives
  • hostility
  • irritability
  • loss of consciousness
  • muscle twitching
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • rapid weight gain
  • seeing, hearing, or feeling things that are not there
  • seizures
  • stupor
  • swelling of the face, ankles, or hands
  • tightness in the chest
  • unusual drowsiness, dullness, or feeling of sluggishness
Incidence not known
  • Cold sweats
  • darkening of the skin
  • decrease in the frequency of urination
  • decrease in the urine volume
  • difficult or troubled breathing
  • difficulty in passing urine (dribbling)
  • dizziness, faintness, or lightheadedness when getting up from lying or sitting position
  • fainting
  • irregular, fast or slow, or shallow breathing
  • overactive reflexes
  • pale or blue lips, fingernails, or skin
  • poor coordination
  • shivering
  • talking or acting with excitement you cannot control
  • trembling or shaking

Some side effects of acetaminophen / caffeine / dihydrocodeine 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:

More common
  • Difficulty having a bowel movement
  • relaxed and calm feeling
  • sleepiness
Incidence not known
  • Constricted, pinpoint, or small pupils (black part of the eye)
  • diarrhea
  • dry mouth
  • gas in the stomach
  • heartburn

For Healthcare Professionals

Applies to acetaminophen / caffeine / dihydrocodeine: oral capsule, oral tablet


The most frequently expected adverse reactions based on the individual components may include lightheadedness, dizziness, drowsiness, sedation, nausea, vomiting, constipation, pruritus and skin reactions.[Ref]


Frequency not reported: Hepatotoxicity[Ref]


Frequency not reported: Respiratory depression, cough suppression[Ref]


Frequency not reported: Confusion, physical and psychological dependence, hallucinations vivid dreams

Frequency not reported: Anxiety, anxiety neurosis, excitement, insomnia, irritability, restlessness, tenseness[Ref]


Frequency not reported: Sweating, pruritus, skin reactions

Rare (less than 0.1%): Serious skin reactions such as acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN)

Frequency not reported: Urticaria[Ref]


Frequency not reported: Anaphylactoid reactions, hypersensitivity reactions

Rare (less than 0.1%): Anaphylactoid reactions
Frequency not reported: Hypersensitivity reactions including urticarial or erythematous skin reactions, laryngeal edema, angioedema[Ref]

Nervous system

Postmarketing reports: Serotonin syndrome

Rare (less than 0.1%): Narcosis
Frequency not reported: Lightheadedness, dizziness, drowsiness, sedation, headache

Frequency not reported: Headaches, lightheadedness, tremor[Ref]


Rare (less than 0.1%): Acute renal failure
Frequency not reported: Granulomatous interstitial nephritis

Frequency not reported: Diuresis[Ref]


Frequency not reported: Orthostatic hypotension

Frequency not reported: Extrasystoles, palpitations, tachycardia[Ref]


Postmarketing reports: Adrenal insufficiency

Frequency not reported: Androgen deficiency[Ref]

Chronic opioid use may influence the hypothalamic-pituitary-gonadal axis and lead to androgen deficiency; however, the causal role of opioids is unknown due to the lack of studies into the many medical, physical, lifestyle, and psychological stressors that influence gonadal hormone levels.[Ref]


Frequency not reported: Nausea, vomiting, constipation, abdominal pain, diarrhea, dry mouth, indigestion, spasm of biliary tract

Frequency not reported: Diarrhea, nausea, stomach pain, vomiting[Ref]


Frequency not reported: Urinary retention[Ref]


Frequency not reported: Thrombocytopenia, leukopenia, pancytopenia, neutropenia, thrombocytopenic purpura, agranulocytosis[Ref]


Frequency not reported: Anorexia[Ref]


Frequency not reported: Miosis

Frequency not reported: Scintillating scotoma[Ref]


Frequency not reported: Fatigue

Frequency not reported: Tinnitus[Ref]


1. "Product Information. APAP/Caffeine/Dihydrocodeine Bitartrate (acetaminophen / caffeine / dihydrocodeine)." Xspire Pharma, Ridgeland, MS.

2. "Product Information. Trezix (acetaminophen / caffeine / dihydrocodeine)." WraSer Pharmaceuticals, Madison, MS.

Some side effects of Trezix may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.