Acetaminophen with Oxycodone

Controlled Substances

Only midwives who have completed the “Opioids and Benzodiazepines: Safe Prescribing for Midwives” course may independently prescribe controlled substances.

(Endocet®, Percocet®). An analgesic combined opioid which blocks pain perception in the cerebral cortex by binding to opiate receptors in the CNS. Binding inhibits the flow of pain sensations and peripherally blocks pain impulses as synthesis of prostaglandins in the central nervous system is inhibited. Produces antipyresis and binds to opiate receptors in the CNS, altering perception and response to pain.

Indications and Clinical Use:

Acetaminophen and oxycodone combined may be prescribed by midwives for up to 72 hours postpartum to relieve moderate to severe pain in the postpartum period following vaginal and/or operative delivery. Midwives may only prescribe, order or administer acetaminophen with oxycodone on their own authority for the purpose of postpartum pain relief and not for any other purpose. If a longer course of a pain medication is required, a non-narcotic medication should be prescribed upon discharge or a referral to a physician to determine if continued use of acetaminophen with oxycodone seems appropriate.

For clients with poorly controlled pain, maximum doses of non-narcotic analgesics such as acetaminophen and nonsteroidal anti-inflammatory drugs should be considered prior to prescribing this medication.


Hypersensitivity to oxycodone, acetaminophen, or any component found in the formulation. Contraindicated in the presence of respiratory depression, bronchial asthma, hypercarbia, paralytic ileus.

Warnings and Precautions:

May cause CNS depression, impairing mental or physical abilities. Use with caution in known G6PD deficiency. May cause hepatotoxicity in the following: with excessive use > greater than 4 g/day of acetaminophen-containing medications; alcohol use; pre-existing liver disease; or chronic daily use. History of substance use should be considered before prescribing or ordering oxycodone as it is an opioid agonist of the morphine-type and can be misused in a similar manner as other opioid agonists, legal or illicit.


Acetaminophen – Human Data Suggest Low Risk

Oxycodone- Human Data Suggest Risk

There is a risk of congenital birth defects if exposure occurs during organogenesis. Use for prolonged periods or at high doses at term can cause respiratory depression or withdrawal in the neonate.


Acetaminophen – Category L1 – Compatible

Oxycodone – Category L3 – Limited Data- Probably Compatible

Oxycodone is considered suitable for short term use in lactation; about 1.5-3.5% of the dose is known to enter breastmilk. The lowest effective dose should be given for the shortest possible period of time. The neonate should also be monitored for signs of sedation, such as not waking up to feed at regular intervals. If ongoing narcotic is required postpartum consider other alternative agents such as hydromorphone.

Adverse Reactions:

Allergic reaction, dizziness, light-headedness, nausea, vomiting, constipation, dysphoria, respiratory depression, sedation, skin rash.

Dosage and Administration:

Usual initial dose for mild to moderate pain:
Oxycodone: PO 2.5mg, Acetaminophen: PO 325mg (every 6 hours prn)

Usual initial dose for severe pain:
Oxycodone: PO 5mg, Acetaminophen: PO 325mg (6 hours prn)

Maximum daily dose:
Oxycodone 20 mg/24 hours. Acetaminophen: 4000 mg/24 hours.

Doses should be given every 6 hours as needed and titrated accordingly based on appropriate analgesic effects.

The initial dose is based on the oxycodone content and the maximum daily dose is based on the acetaminophen content.


Acetaminophen with oxycodone may be prescribed in hospital or in the community. If Acetaminophen with oxycodone is prescribed in the community, a controlled drugs and substances duplicate prescription pad must be used[1]. A prescription cannot exceed three days. No refills.

[1] Regulator-approved controlled drugs and substances duplicate prescription pads are not yet available for use by midwives.

Onset of Action:

10-30 minutes

Time to peak effect: 30-60 minutes


Adult – 2 hours for acetaminophen, ranges from 3.7 (2-4 hours) for oxycodone, 5 hours for extended release

Neonate – 7 hours for acetaminophen, 1.2-3 hours for oxycodone

Prescribing extended-release analgesic medication is not within midwifery scope of practice. If a client has been prescribed or is currently taking an extended release prescription medication such as oxycodone or hydromorphone and requires additional pain management in labour or during the early postpartum period, a physician consultation or order is required.


In urine as metabolites