Is hydrocodone the same as oxycodone?

No, Hydrocodone and Oxycodone Are Not the Same Drug

Hydrocodone and oxycodone are two distinct semi-synthetic opioid analgesics with different chemical structures, slightly different potency profiles, and potentially different clinical outcomes, though they produce similar analgesic effects at equianalgesic doses. 1, 2

Chemical and Pharmacological Differences

• Oxycodone is approximately 1.5 times more potent than hydrocodone on a milligram-to-milligram basis, requiring dose adjustment when converting between the two agents. 2, 3

• Both are semi-synthetic opioid agonists derived from morphine congeners, but they have distinct molecular structures and metabolic pathways. 1

• Oxycodone has better oral bioavailability (60-90%) compared to hydrocodone, which affects their relative dosing when administered orally. 1

• The drugs differentially affect dopamine D2/D3 receptors, with oxycodone producing greater dopaminergic supersensitivity than hydrocodone in preclinical models. 4

Clinical Efficacy Comparisons

• At equianalgesic doses, hydrocodone and oxycodone provide equivalent pain relief with no clinically significant differences in efficacy, adverse effects, or patient satisfaction. 1, 2

• A prospective randomized trial comparing oxycodone 5 mg/acetaminophen with hydrocodone 7.5 mg/ibuprofen found no differences in pain relief, doses taken, global efficacy evaluations, health status, or pain interference with work over an 8-day period. 1

• In non-drug-abusing volunteers, equi-miotic doses of oxycodone/acetaminophen and hydrocodone/acetaminophen produced similar prototypic opioid effects and psychomotor impairment of comparable magnitude. 5

Critical Safety and Outcome Differences

Despite similar analgesic efficacy, these drugs carry different risks for adverse outcomes:

• Oxycodone is associated with significantly higher risk of opioid overdose (adjusted hazard ratio 1.65,95% CI 1.45-1.87) compared to hydrocodone in opioid-naïve patients. 6

• Oxycodone monotherapy carries the highest overdose risk (adjusted hazard ratio 2.18,95% CI 1.86-2.57) compared to hydrocodone/acetaminophen combinations. 6

• Hydrocodone is associated with substantially higher rates of transition to long-term use (estimated 12% vs. 2% for oxycodone) in primary care patients with acute back pain. 7

• Among patients receiving more than one prescription, 23% of hydrocodone-treated patients transitioned to long-term use versus only 5% of oxycodone-treated patients. 7

Regulatory Classification

• Both hydrocodone and oxycodone single-entity formulations are currently Schedule II controlled substances under federal drug scheduling. 1, 8, 3

• Historically, hydrocodone combination products were Schedule III until 2014, while oxycodone combinations have always been Schedule II, but this classification reflects abuse potential rather than analgesic efficacy. 1, 2, 3

Prescribing Recommendations

• Initial dosing for immediate-release formulations is 5-15 mg every 4-6 hours as needed for both agents, adjusted for the 1.5:1 potency ratio (oxycodone:hydrocodone). 1, 8, 3

• Given the lower overdose risk, hydrocodone may be the favorable agent when prescribing for opioid-naïve patients, particularly when combined with acetaminophen. 6

• However, hydrocodone's higher risk of transition to long-term use must be weighed against oxycodone's higher acute overdose risk when selecting between agents. 6, 7

• Prescriptions should clearly state the specific drug name, release mechanism (immediate vs. extended), and exact dose to prevent medication errors, as these are not interchangeable medications. 8

• Extended-release formulations of either drug (e.g., OxyContin) should not be used for acute pain and are indicated only for opioid-tolerant patients with chronic pain. 1, 3

Common Pitfall to Avoid

Do not assume these drugs are interchangeable or that one is simply "stronger" than the other. While oxycodone is more potent per milligram, this does not translate to superior analgesia at equianalgesic doses. The choice between hydrocodone and oxycodone should be based on the specific clinical context: prioritize hydrocodone to minimize acute overdose risk, but monitor more carefully for transition to long-term use; conversely, oxycodone may be appropriate when short-term use is assured but carries higher immediate overdose risk. 2, 6, 7