Ultracet (tramadol / acetaminophen)

Pronunciation: TRAM-a-dol / a-SEET-a-MIN-oh-fen.

Generic name
tramadol hydrochloride and acetaminophen
Drug class
Opioid analgesic (tramadol) combined with a non-opioid analgesic (acetaminophen/paracetamol)
Form
Film-coated tablet, 37.5 mg tramadol hydrochloride / 325 mg acetaminophen (some markets also have an effervescent tablet form)
Route
Oral
Legal status
Prescription-only; controlled substance (Schedule IV in the United States) because of the tramadol component

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia

Australia: Zaldiar (7), Tramadol/Paracetamol 37.5/325 Apotex (generic) (7) · Full directory

What tramadol hydrochloride and acetaminophen is and how it works

Ultracet combines tramadol, an opioid pain reliever, with acetaminophen (paracetamol), a non-opioid pain reliever, in a single tablet. Combining the two allows effective pain relief for moderate to severe short-term pain. (2) (4)

This medicine is intended for short-term use only (typically five days or less in the US labelling) for acute pain that needs an opioid, when other pain relievers have not been enough. Because it contains an opioid, it carries real risks of dependence, breathing problems, and interactions with other sedating medicines or alcohol, so it is only used exactly as your prescriber directs, for as short a time as possible.

Mechanism of action: how tramadol hydrochloride and acetaminophen works

Tramadol is a centrally acting synthetic opioid analgesic; its analgesic activity results from both binding of the parent compound and its M1 metabolite to mu-opioid receptors and weak inhibition of norepinephrine and serotonin reuptake. Acetaminophen (paracetamol) is a non-opioid, non-salicylate analgesic and antipyretic whose exact central mechanism is not fully established. The combination provides analgesia through complementary mechanisms. (2) (4)

What tramadol hydrochloride and acetaminophen is used for

Short-term management of acute pain

Used for the management of acute pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate, typically for five days or less. (2)

Moderate to severe pain (combination-specific indication outside the US)

In the UK, EU, Canada, and Australia, this combination is indicated for the symptomatic treatment of moderate to severe pain, restricted to patients whose pain is considered to specifically require a tramadol/paracetamol combination rather than either ingredient alone. (4)

Before taking tramadol hydrochloride and acetaminophen

Do not take / not appropriate for

  • Do not take this medicine if you have a known allergy to tramadol, acetaminophen/paracetamol, or any opioid. (all countries) (1) (4)
  • Do not take this medicine if you are acutely intoxicated with alcohol, sleeping tablets, other opioids, or other centrally acting/psychotropic medicines. (all countries) (1) (4)
  • Do not take this medicine if you are taking, or have taken within the last 2 weeks, a monoamine oxidase inhibitor (MAOI). (United Kingdom, European Union, Canada, Australia) (4)
  • Do not give this medicine to children under 12 years of age, or to anyone under 18 who has had their tonsils or adenoids removed. (all countries) (2)
  • Do not take this medicine if you have severe liver impairment or uncontrolled epilepsy. (United Kingdom, European Union, Canada, Australia) (4)
  • Do not take any other medicine that also contains acetaminophen/paracetamol while taking this medicine. (all countries) (2)

Tell your clinician about

  • Any personal or family history of substance use disorder, opioid misuse, or addiction.
  • Any history of seizures, head injury, or conditions that lower the seizure threshold.
  • Any history of liver or kidney problems.
  • Whether you are taking antidepressants (including SSRIs, SNRIs, or tricyclics), triptans, or other medicines that affect serotonin, given the risk of serotonin syndrome.
  • Whether you are pregnant, plan to become pregnant, or are breastfeeding.
  • Whether you drink alcohol regularly or take sedatives, sleeping tablets, or benzodiazepines.
(2) (4)

How to take tramadol hydrochloride and acetaminophen

  • Take exactly as prescribed, for the shortest duration needed to control your pain -- typically five days or less.
  • Do not increase your dose or take it more often than prescribed, even if your pain is not fully controlled -- contact your prescriber instead.
  • Do not stop taking this medicine suddenly after extended use without medical guidance, as withdrawal symptoms can occur.
  • Never combine with alcohol or other sedating medicines unless your prescriber has specifically approved it.
(2) (4)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6) (7) (8)

Missed dose

This medicine is normally taken as needed for pain rather than on a fixed schedule. If you have been given a fixed dosing schedule and miss a dose, contact your prescriber or pharmacist for guidance rather than doubling your next dose.

Overdose

Seek emergency medical help immediately if an overdose is suspected, including accidental ingestion by a child of even a single tablet. Signs can include severe drowsiness, slow or shallow breathing, pinpoint pupils, confusion, seizures, nausea, vomiting, abdominal pain, or (from the acetaminophen component) signs of liver injury such as loss of appetite or yellowing of the skin/eyes, which can appear days after the overdose. Overdose is a medical emergency requiring urgent hospital treatment, which may include naloxone for the opioid component and N-acetylcysteine for the acetaminophen component -- N-acetylcysteine is most effective if started within 8 hours but should still be given as soon as possible even later. (4) (2)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Nausea, dizziness, and drowsiness (somnolence).

What to notice: Nausea, dizziness, and drowsiness (somnolence).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (4)

Constipation.

What to notice: Constipation.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1) (4)

Increased sweating.

What to notice: Increased sweating.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Headache and tremor.

What to notice: Headache and tremor.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (4)

Vomiting and diarrhoea.

What to notice: Vomiting and diarrhoea.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1) (4)

Serious warnings

Signs of opioid addiction, abuse, or misuse — boxed_warning

Symptoms: Taking more than prescribed, seeking early refills, using the medicine for reasons other than pain, or drug-seeking behaviour.

Action: Discuss any concerns about dependence honestly with your prescriber -- this is a recognised, monitored risk of the medicine, not a personal failing, and your care team can help manage it safely. (2) (4)

Signs of life-threatening respiratory depression — boxed_warning

Symptoms: Very slow, shallow, or stopped breathing; extreme drowsiness; unresponsiveness; blue-tinged lips or fingertips.

Action: This is a medical emergency -- call emergency services immediately. Risk is highest when starting treatment, after a dose increase, or when combined with alcohol or other sedating medicines. (2)

Accidental ingestion by a child — boxed_warning

Symptoms: Any ingestion of even one tablet by a child, whether or not symptoms are yet visible.

Action: Seek emergency medical help immediately -- even a single dose can be fatal to a child. Store tablets securely and out of reach of children at all times. (2)

Signs of serious liver injury (from the acetaminophen component) — boxed_warning

Symptoms: Loss of appetite, nausea, unusual tiredness, upper right abdominal discomfort, dark urine, or yellowing of the skin or eyes (jaundice).

Action: Seek medical attention promptly and ask the prescriber about stopping it unless directed otherwise by your clinician -- never exceed the recommended dose or combine with other acetaminophen/paracetamol-containing products. (2)

Signs of serotonin syndrome — high caution

Symptoms: Agitation, confusion, rapid heart rate, high blood pressure, dilated pupils, muscle twitching or rigidity, sweating, shivering, diarrhoea, and fever.

Action: Seek urgent medical attention, especially if you also take antidepressants, triptans, or other serotonergic medicines. (4)

Seizures — high caution

Symptoms: Convulsions, which can occur at recommended doses but are more likely above the recommended dose or with certain other medicines.

Action: Seek emergency medical help for any seizure; tell your prescriber about any personal history of seizures or epilepsy before starting treatment. (4)

Signs of a serious allergic reaction — emergency

Symptoms: Swelling of the face, lips, tongue, or throat; difficulty breathing; widespread rash or hives; anaphylaxis.

Action: Seek emergency medical help immediately. (4)

Interactions

  • Benzodiazepines and other CNS depressants (including alcohol, sleeping tablets, and other opioids) increase the risk of profound sedation, breathing problems, coma, and death when combined with this medicine. (2)
  • Monoamine oxidase inhibitors (MAOIs), including within 2 weeks of stopping one, must not be combined with this medicine. (4)
  • SSRIs, SNRIs, tricyclic antidepressants, triptans, and other serotonergic medicines increase the risk of serotonin syndrome and seizures. (4)
  • Strong CYP3A4/CYP2D6-affecting medicines (such as certain antifungals, macrolide antibiotics, and some antidepressants) can change tramadol and its active metabolite's levels in complex ways -- discuss any new medicine with your prescriber or pharmacist. (2)
  • Carbamazepine is not recommended with this medicine, as it can substantially reduce tramadol's effectiveness. (4)
  • Warfarin and other blood-thinning medicines may need closer monitoring when combined with this medicine. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Not recommended in pregnancy; if opioid treatment is required for an extended period during pregnancy, the baby is at risk of neonatal opioid withdrawal syndrome after birth, which can be life-threatening if not recognised and treated in a setting with neonatal specialists available. (1) (2) (3) (4) (5) (6) (7) (8)

Breastfeeding

Not recommended for use during breastfeeding as ongoing treatment; discontinuing breastfeeding is generally not considered necessary after a single dose, but prolonged use should be discussed with your prescriber. (1) (2) (3) (4) (5) (6) (7) (8)

Children

Contraindicated under 12 years of age, and in anyone under 18 who has had tonsils or adenoids removed, because of reports of life-threatening breathing problems and death. Caution advised in other adolescents 12-18 years with additional risk factors for respiratory depression. (1) (2) (3) (4) (5) (6) (7) (8)

Elderly

Cautious dose selection recommended, reflecting the greater likelihood of reduced liver, kidney, or heart function, and prolonged drug elimination in patients over 75. (1) (2) (3) (4) (5) (6) (7) (8)

Hepatic_impairment

Use not recommended (US labelling) or contraindicated in severe impairment (UK/EU/Canada/Australia labelling), given the combined risks of opioid accumulation and acetaminophen-related liver injury. (1) (2) (3) (4) (5) (6) (7) (8)

Renal_impairment

Dosing interval should be extended (e.g. no more than every 12 hours) in patients with a creatinine clearance under 30 mL/min. (1) (2) (3) (4) (5) (6) (7) (8)

Source_ids

US-DAILYMED-ULTRACET-BRAND-2011,US-DAILYMED-GENERIC-TRAMADOL-ACET-CURRENT-2026,UK-EMC-TRAMACET-2026 (1) (2) (3) (4) (5) (6) (7) (8)

Monitoring

Before starting

  • Assessment of individual risk for opioid addiction, abuse, or misuse
  • Review of liver and kidney function
  • Review of other medicines for serotonergic, MAOI, or CNS-depressant interactions
  • Seizure history

During treatment

  • Regular reassessment for signs of opioid misuse, dependence, or drug-seeking behaviour.
  • Monitoring for excessive sedation or slowed breathing, especially at treatment initiation or after a dose change.
  • Monitoring for signs of liver injury given the acetaminophen component, particularly with prolonged or high-dose use.
(2) (4)

Storage

Store below 25°C (or as labelled), in the original packaging, out of reach and sight of children -- accidental ingestion of even one tablet can be fatal to a child.

Professional information

Clinician-facing context only, sourced from the current US generic tramadol/acetaminophen DailyMed label, the original 2011 ULTRACET brand label, and the UK Tramacet SmPC; verify against the current full label before prescribing.

United States

Indication: Acute pain requiring an opioid, short-term (typically <=5 days)

Dose summary: 2 tablets every 4-6 hours as needed, maximum 8 tablets/day; extend interval to every 12 hours if CrCl <30 mL/min; not recommended in hepatic impairment.

Renal context: CrCl <30 mL/min: maximum 2 tablets every 12 hours. (1) (2)

United Kingdom / European Union / Canada / Australia

Indication: Moderate to severe pain requiring a tramadol/paracetamol combination

Dose summary: Initial 2 tablets, additional doses as needed at intervals >=6 hours, maximum 8 tablets/day; not for children <12 years; contraindicated in severe hepatic impairment.

Renal context: Extend dosing interval in renal impairment; use with caution and consider dose adjustment. (4)

Mechanism of action

Hepatic guidance

Acetaminophen carries a real risk of acute liver failure, particularly above 4,000 mg/day or with concomitant use of other acetaminophen-containing products; combined tramadol/acetaminophen use is not recommended, or contraindicated in severe cases, in patients with hepatic impairment.

Overdose note

Naloxone reverses the opioid (tramadol) component's respiratory depression but does not reduce the risk of seizure; N-acetylcysteine treats acetaminophen toxicity and is most effective within 8 hours of ingestion but should be given as soon as possible regardless of timing. (2) (4)

Frequently asked questions

Is Ultracet still available, or has it been discontinued?

The original ULTRACET brand has been discontinued in the United States. However, the identical combination of tramadol hydrochloride and acetaminophen remains FDA-approved and is actively marketed as a generic. Outside the US, the same combination is sold as Tramacet (UK, Canada) or Zaldiar (EU, Australia). (3) (2)

Is this medicine available in the US, UK, Europe, Canada, Australia, and New Zealand?

The tramadol/acetaminophen combination is confirmed authorised in the US (as a generic), UK, EU (nationally in multiple member states), Canada, and Australia. Its status in New Zealand specifically for the combination product could not be confirmed despite thorough searching -- tramadol alone is registered there, but no record of the combination product was found. (2) (4) (5) (6) (7) (8)

Why can't I take this with other pain relievers containing acetaminophen or paracetamol?

Because this medicine already contains 325 mg of acetaminophen per tablet, taking another acetaminophen/paracetamol-containing product at the same time risks exceeding the safe daily limit (4,000 mg), which can cause serious, potentially fatal liver damage. (2)

Why is this medicine only for short-term use?

Because it contains an opioid (tramadol), longer use raises the risk of dependence, tolerance, and withdrawal. US labelling recommends use for five days or less; your prescriber will advise if longer treatment is genuinely needed and how to do so safely. (2)

What is the mechanism of action of tramadol hydrochloride and acetaminophen?

Tramadol is a centrally acting synthetic opioid analgesic; its analgesic activity results from both binding of the parent compound and its M1 metabolite to mu-opioid receptors and weak inhibition of norepinephrine and serotonin reuptake. Acetaminophen (paracetamol) is a non-opioid, non-salicylate analgesic and antipyretic whose exact central mechanism is not fully established. The combination provides analgesia through complementary mechanisms. (2) (4)

What is the generic name of Ultracet (tramadol / acetaminophen)?

The generic name is tramadol hydrochloride and acetaminophen. (2) (1) (4)

What class of drug is tramadol hydrochloride and acetaminophen?

Ultracet (tramadol / acetaminophen) is classed as: Opioid analgesic (tramadol) combined with a non-opioid analgesic (acetaminophen/paracetamol). (2) (1) (4)

References

  1. ULTRACET (tramadol hydrochloride and acetaminophen) tablets -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH) -- original ULTRACET brand full prescribing information (2011 label revision, pre-2016 class-wide opioid labeling update) · United States · accessed 2026-07-30 · source 1
  2. TRAMADOL HYDROCHLORIDE AND ACETAMINOPHEN tablet -- full prescribing information (current generic, ANDA-approved equivalent of discontinued ULTRACET brand)U.S. Food and Drug Administration / DailyMed (NIH) -- current generic tramadol hydrochloride/acetaminophen tablet label (ANDA, e.g. Amneal/Preferred Pharmaceuticals), reflecting the standardized 2016 class-wide opioid analgesic boxed warning · United States · accessed 2026-07-30 · source 2
  3. Ultracet brand discontinuation / generic availabilityMultiple secondary US sources (Drugs.com generic-availability page, search aggregation) describing FDA/manufacturer market status · United States · accessed 2026-07-30 · source 3
  4. Tramacet 37.5 mg/325 mg film-coated tablets -- Summary of Product Characteristics (PL 50414/0024)electronic medicines compendium (emc), United Kingdom -- Grunenthal Pharma Ltd · United Kingdom · accessed 2026-07-30 · source 4
  5. Paracetamol/tramadol -- list of nationally authorised medicinal products (PSUSA/00002310)European Medicines Agency (EMA) -- Periodic Safety Update Report Single Assessment (PSUSA) documentation for paracetamol/tramadol · European Union · accessed 2026-07-30 · source 5
  6. TRAMACET (tramadol hydrochloride/acetaminophen) and TARO-TRAMADOL/ACET Product MonographsHealth Canada product monographs -- Janssen-Ortho Inc. (Tramacet) and generic sponsors (e.g. Taro Pharmaceuticals) · Canada · accessed 2026-07-30 · source 6
  7. ZALDIAR tramadol hydrochloride/paracetamol 37.5 mg/325 mg effervescent tablets (ARTG 179678); TRAMADOL/PARACETAMOL 37.5/325 APOTEX film-coated tablets (ARTG 280698)Therapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-30 · source 7
  8. TRAMAL (tramadol) New Zealand Data Sheet -- monotherapy product, cited to establish what IS confirmed for New ZealandMedsafe (New Zealand regulator) · New Zealand · accessed 2026-07-30 · source 8

Brand names by country

Single-ingredient tramadol hydrochloride and acetaminophen names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Ultracet (1) (3)brand discontinued no longer marketed · 37.5 mg / 325 mg · originally Ortho-McNeil-Janssen Pharmaceuticals
  • Tramadol hydrochloride and acetaminophen (generic) (2)FDA approved currently marketed ANDA · 37.5 mg / 325 mg · multiple ANDA holders, e.g. Amneal Pharmaceuticals / Preferred Pharmaceuticals

United Kingdom

  • Tramacet (4)MHRA licensed emc smpc confirmed · 37.5 mg / 325 mg · Grunenthal Pharma Ltd (PL 50414/0024)

Canada

  • Tramacet (6)Health Canada approved confirmed · 37.5 mg / 325 mg · Janssen-Ortho Inc.
  • TARO-TRAMADOL/ACET (generic) (6)Health Canada approved confirmed · 37.5 mg / 325 mg · Taro Pharmaceuticals Inc.

Australia

  • Zaldiar (7)TGA ARTG registered confirmed · 37.5 mg / 325 mg · ARTG 179678
  • Tramadol/Paracetamol 37.5/325 Apotex (generic) (7)TGA ARTG registered confirmed · 37.5 mg / 325 mg · ARTG 280698, Apotex Pty Ltd
View brands in additional countries.

European Union

Zaldiar (5)

This page provides general reference information about the tramadol/acetaminophen combination (Ultracet and its equivalents) and is not a substitute for advice from the prescriber managing your treatment. All dosing and treatment decisions should be made with your prescriber.

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