Acetaminophen; Hydrocodone

What it is

A combination tablet containing hydrocodone, a full opioid agonist that acts mainly at the mu-opioid receptor, and acetaminophen (paracetamol), a non-opioid pain reliever whose mechanism is not fully established. It is a Schedule II opioid in the US.

What the research says

In a single-dose dental-surgery trial it relieved pain better than placebo, but in an emergency-department trial it gave no clinically important advantage over ibuprofen plus acetaminophen, and in a 12-month trial of chronic back, hip or knee pain an opioid strategy that started with drugs including hydrocodone/acetaminophen was not better for function and was worse for pain intensity and side effects than non-opioid drugs. Harms include addiction, respiratory depression, overdose, and liver failure from the acetaminophen component at high doses.

Evidence grade: Limited evidence.

How it works

Drug class: Opioid agonist (hydrocodone) combined with a non-opioid analgesic (acetaminophen/paracetamol)

Hydrocodone binds and activates opioid receptors, mainly the mu receptor, in the nervous system, which dulls pain signals and also slows breathing. How acetaminophen relieves pain is not established but is thought to involve actions in the brain and spinal cord. (Source 1)

Boxed warning

Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed 4,000 milligrams per day

(Source 2)

What it is used for

• Better than placebo after dental surgery in a small single-dose trial, but in an emergency-department trial of limb pain it was no better than ibuprofen plus acetaminophen at 2 hours. Evidence: limited. (Source 3)
• Long-term use for chronic pain is outside the acute-pain labelling. In the 12-month SPACE trial, an opioid strategy (including hydrocodone/acetaminophen) was not superior to non-opioid drugs for function and caused more side effects. Evidence: not-supported. (Source 4)

Interactions

• Alcohol (label): Combining opioids with alcohol or other CNS depressants can cause profound sedation, slowed breathing, coma and death. (Source 2)
• Chronic alcohol use, fasting or malnutrition (acetaminophen component) (theoretical): Chronic alcohol use and low glutathione states (fasting, malnutrition, alcoholism) predispose to acetaminophen liver toxicity. (Source 5)
• CYP3A4 inhibitors (drugs) (label): Drugs that block the CYP3A4 enzyme can raise hydrocodone blood levels. (Source 2)
• Benzodiazepines and other sedatives (label): Combined sedation and respiratory depression, which can be fatal. (Source 2)

Stopping it

• The label (April 2026) says not to stop suddenly or cut the dose rapidly in someone physically dependent; the dose should be tapered gradually. (Source 1)
• Physical dependence shows up as withdrawal symptoms after abrupt stopping or a large dose cut. (Source 1)
• In a large observational study of people on long-term higher-dose opioids, tapering was associated with more overdoses and mental health crises (as reported by the university news release). (Source 6)

What goes wrong

People on the opioid strategy reported about twice as many medication-related symptoms on a symptom checklist as those on non-opioid drugs over 12 months (an average count of symptoms, not the share of people affected). (Source 4)

• Randomized trial, Moderate certainty.
• Size: 240 randomized.
• Who: US veterans with chronic back, hip or knee pain.
• How long: 12 months.
• Result: Mean number of medication-related symptoms at 12 months 1.8 opioid vs 0.9 non-opioid (difference 0.9, 95% CI 0.3 to 1.5; overall P = .03).
• Funding: Not stated in the abstract.

Adverse medication-related symptoms were significantly more common in the opioid group over 12 months (overall P = .03)

Nausea and vomiting were common after a single hydrocodone/acetaminophen dose in dental-surgery patients. (Source 3)

• Randomized trial, Low certainty.
• Size: 200 participants.
• Who: Adults after wisdom-tooth extraction.
• How long: Single dose.
• Result: Nausea 36% and vomiting 30% with HC/APAP, versus 18% and 12% with 2 tramadol/APAP tablets.
• Funding: Not stated in the text we read.

The incidence of nausea (18% T/APAP, 36% HC/APAP) and vomiting (12% T/APAP, 30% HC/APAP) was ∼50% lower with 2 T/APAP tablets than with HC/APAP (P < 0.05).

Acetaminophen, the other ingredient, is the leading cause of acute liver failure in the US, Europe and Australia. (Source 5)

• Official position, Certainty not rated.
• Size: Not applicable (reference review)
• Who: General population.
• How long: Not applicable.
• Result: No rate given in the passage we recorded.
• Funding: Independent (NIH)

Currently, acetaminophen is the major cause of acute liver failure in the United States, Europe and Australia.

Tapering stable long-term high-dose opioid prescriptions was associated with more overdoses and mental health crises (observational, reported via a university news release on the JAMA study). (Source 6)

• Cohort study, Low certainty.
• Size: 113,618 patients (per news release)
• Who: US patients on stable long-term opioid doses of 50 MME/day or more.
• How long: Baseline year plus at least 2 months follow-up.
• Result: 68% increase in overdose events and a doubling of mental health crises among tapered vs non-tapered patients.
• Funding: Not stated in the text we read.

Limit of this finding: This finding rests only on a university news release describing the JAMA study (Agnoli et al., 2021); we did not read the paper itself. The study was observational, so it shows an association, not that tapering caused the harms.

a 68% increase in overdose events and a doubling of mental health crises among tapered as compared to non-tapered patients.

The FDA label (April 2026) carries a boxed warning for addiction, abuse and misuse, life-threatening respiratory depression, accidental ingestion, neonatal withdrawal, CYP3A4 interactions, hepatotoxicity and combined use with benzodiazepines or alcohol. (Source 2)

• Official position, Certainty not rated.
• Size: Not applicable.
• Who: Label position.
• How long: Not applicable.
• Result: Not applicable.
• Funding: Manufacturer label approved by FDA.

Serious, life-threatening, or fatal respiratory depression may occur with use of hydrocodone bitartrate and acetaminophen tablets, especially during initiation or following a dosage increase.

What the evidence supports

Hydrocodone/acetaminophen relieved pain better than placebo in a single-dose dental-surgery trial. (Source 3)

• Randomized trial, Low certainty.
• Size: 200 participants.
• Who: Adults with at least moderate pain after removal of 2 or more impacted wisdom teeth.
• How long: Single dose.
• Result: Both tramadol/APAP 75/650 mg and HC/APAP were statistically superior to placebo on TOTPAR, SPID and SPRID (P <= 0.024), and on hourly PAR, PID and PRID over 6 hours (P <= 0.045).
• Funding: Not stated in the text we read; comparator product was tramadol/APAP, likely manufacturer-linked authors.

T/APAP 75/650 mg and HC/APAP were statistically superior to placebo on the primary efficacy measures of TOTPAR, SPID, and SPRID (P ≤ 0.024), as well as on hourly PAR, PID, and PRID over 6 hours (P ≤ 0.045).

What the evidence does not support

For acute limb pain in the emergency department, hydrocodone/acetaminophen was no better than ibuprofen plus acetaminophen at 2 hours. (Source 7)

• Randomized trial, Moderate certainty.
• Size: 416 randomized, 411 analyzed.
• Who: Adults 21-64 with moderate to severe acute extremity pain in 2 Bronx EDs.
• How long: 2 hours after one dose.
• Result: Pain fell 3.5 points (95% CI 2.9 to 4.2) with hydrocodone/APAP vs 4.3 (3.6 to 4.9) with ibuprofen/APAP on a 0-10 scale; P = .053 overall. Adverse events were not assessed.
• Funding: Not stated in the abstract.

At 2 hours, the mean NRS pain score decreased by 4.3 (95% CI, 3.6 to 4.9) in the ibuprofen and acetaminophen group

Over 12 months for chronic back, hip or knee pain, an opioid strategy (first step morphine, oxycodone or hydrocodone/acetaminophen) was not better for function than non-opioid drugs, and pain intensity was worse. (Source 4)

• Randomized trial, Moderate certainty.
• Size: 240 randomized.
• Who: US veterans with moderate to severe chronic back pain or hip or knee osteoarthritis pain.
• How long: 12 months.
• Result: BPI interference 3.4 opioid vs 3.3 non-opioid (difference 0.1, 95% CI -0.5 to 0.7); BPI severity 4.0 vs 3.5 (difference 0.5, 95% CI 0.0 to 1.0).
• Funding: Not stated in the abstract (Veterans Affairs setting)

Treatment with opioids was not superior to treatment with nonopioid medications for improving pain-related function over 12 months.

Where the research disagrees

Whether an opioid combination adds benefit over non-opioid analgesics

• FDA-approved label (2026), position: Indicated for pain severe enough to require an opioid; carries a boxed warning. (Source 2)
• Krebs et al., SPACE trial (2018), rct: "Results do not support initiation of opioid therapy for moderate to severe chronic back pain or hip or knee osteoarthritis pain." (Source 4)

How much

• Reference intake: Dosing is set by the prescriber. As a position, the label (April 2026) tells patients not to take more than 4,000 mg of acetaminophen per day from all sources. (Source 1)
• Upper limit: Label position (April 2026): no more than 4,000 milligrams of acetaminophen per day; most liver injury cases involve doses above this. (Source 1)
• Studied: Chang 2017: a single dose of 5 mg hydrocodone with 300 mg acetaminophen in the emergency department. (Source 7)
• Studied: Fricke 2002: a single HC/APAP tablet after wisdom-tooth extraction. (Source 3)

A common belief, and what the research shows

The belief: An opioid combination is always a stronger painkiller than over-the-counter options.

What the research shows: In an ED trial there were "no statistically significant or clinically important differences in pain reduction at 2 hours among single-dose treatment with ibuprofen and acetaminophen or with 3 different opioid and acetaminophen combination analgesics."

Questions and answers

What is it?

A prescription tablet combining hydrocodone, an opioid, with acetaminophen (paracetamol). Hydrocodone is a full opioid agonist that acts mainly on the mu-opioid receptor. (Source 1)

What does it do in the body?

Hydrocodone activates opioid receptors to reduce pain but also slows breathing; acetaminophen is thought to act centrally. In trials it beat placebo for dental pain but was not better than ibuprofen plus acetaminophen for acute limb pain. (Source 1)

Is it good or bad for you?

It can relieve short-term acute pain, but for chronic back, hip or knee pain a 12-month trial found no functional benefit over non-opioid drugs and more side effects. It carries risks of addiction, overdose, respiratory depression and liver injury. (Source 4)

How do you get more of it?

It is available only on prescription; the dose is set by the prescriber. The label caps total acetaminophen from all sources at 4,000 mg per day as a position. (Source 1)

If it is harmful, what reduces it?

Stopping should be gradual in anyone physically dependent; the label says not to stop abruptly. Observational data link tapering of long-term high doses with overdose and mental health crises, so tapering is a supervised process. (Source 1)

Why might someone be low in it or missing it?

Does not apply: this is a medicine, not a nutrient or body component, so no one is deficient in it. (Source 2)

We searched: Label and trial abstracts read for this entry; the question does not apply to a drug.

Which whole foods contain it or feed it?

Does not apply: no food contains hydrocodone. Alcohol is the key dietary interaction and can be dangerous with it. (Source 2)

What happens if you do not have it?

Does not apply as a deficiency. Not taking it means relying on other pain relief; in the ED trial ibuprofen plus acetaminophen performed similarly at 2 hours. (Source 7)

How can you test for it?

No test is needed to use it; we did not source literature on urine or blood opioid testing or its reliability for this entry. (Source 2)

We searched: Did not search drug-testing literature within the search budget; label read.

References

1. US National Library of Medicine DailyMed. Hydrocodone Bitartrate and Acetaminophen Tablets prescribing information, dosage, dependence and mechanism sections (DailyMed, updated April 20, 2026). 2026. Read the source
2. US National Library of Medicine DailyMed. Hydrocodone Bitartrate and Acetaminophen Tablets prescribing information (DailyMed, updated April 20, 2026). 2026. Read the source
3. Clinical Therapeutics. A double-blind, single-dose comparison of the analgesic efficacy of tramadol/acetaminophen combination tablets, hydrocodone/acetaminophen combination tablets, and placebo after oral surgery. 2002. PMID 12117085, DOI 10.1016/S0149-2918(02)80010-8. Read the source
4. JAMA. Effect of Opioid vs Nonopioid Medications on Pain-Related Function in Patients With Chronic Back Pain or Hip or Knee Osteoarthritis Pain: The SPACE Randomized Clinical Trial. 2018. PMID 29509867, DOI 10.1001/jama.2018.0899. Read the source
5. NIDDK / NCBI Bookshelf. LiverTox: Acetaminophen. 2016. Read the source
6. UC Davis Health. Is reducing opioids for pain patients linked to higher rates of overdose and mental health crisis? (UC Davis Health news release on Agnoli et al., JAMA 2021, doi 10.1001/jama.2021.11013). 2021. DOI 10.1001/jama.2021.11013. Read the source
7. JAMA. Effect of a Single Dose of Oral Opioid and Nonopioid Analgesics on Acute Extremity Pain in the Emergency Department: A Randomized Clinical Trial. 2017. PMID 29114833, DOI 10.1001/jama.2017.16190. Read the source