NAPRELAN

Clinical safety rating: caution

Comprehensive clinical and safety monograph for NAPRELAN (NAPRELAN).

How it works

Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis, which mediates pain, inflammation, and fever.

What the body does with it

Metabolism	Primarily hepatic via CYP1A2 and CYP2C9; minor metabolism via glucuronidation and other pathways.
Excretion	Renal: 50-60% as metabolites and conjugates; biliary/fecal: ~5%; remainder uncharacterized.
Half-life	Terminal elimination half-life: 10-20 hours; context: allows twice-daily or once-daily dosing for chronic pain or inflammation.
Protein binding	>99% bound, primarily to albumin.
Volume of Distribution	0.16 L/kg; clinical meaning: low Vd indicates limited tissue distribution, predominantly in plasma.
Bioavailability	Oral (conventional): ~95%; NAPRELAN: approximately 85% of conventional naproxen (due to controlled-release matrix).
Onset of Action	Oral: 1-2 hours (as conventional tablet); NAPRELAN (controlled-release): 2-4 hours.
Duration of Action	12-24 hours; clinical note: NAPRELAN formulation provides sustained plasma levels for twice-daily dosing.

Classification & Brands

Dosing & administration

750 mg to 1000 mg orally once daily, with or without food.

Dosage form	TABLET, EXTENDED RELEASE
Renal impairment	CrCl <30 mL/min: avoid use; CrCl 30-59 mL/min: reduce dose to 500 mg once daily or use alternative.
Liver impairment	Child-Pugh Class B or C: reduce dose to 500 mg once daily or avoid use; monitor for toxicity.
Pediatric use	Not established for children under 18 years; safety and efficacy not determined.
Geriatric use	Initiate at lowest effective dose (e.g., 500 mg once daily); monitor renal function and adjust as needed.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for NAPRELAN (NAPRELAN).

Breastfeeding	Naproxen is excreted into breast milk in small amounts; M/P ratio is approximately 0.01. The American Academy of Pediatrics considers it compatible with breastfeeding, but caution is advised, especially in preterm infants or neonates with compromised renal function. Monitor infant for drowsiness, poor feeding, or jaundice.
Teratogenic Risk	Naproxen (NAPRELAN) is contraindicated in the third trimester due to risk of premature closure of ductus arteriosus and oligohydramnios. In first and second trimesters, use only if clearly needed; limited data suggest possible association with spontaneous abortion and cardiac defects, but absolute risk is low.

Warnings & precautions

■ FDA Black Box Warning

Nonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may occur early in treatment and may increase with duration of use. Naproxen is contraindicated in the setting of coronary artery bypass graft (CABG) surgery.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to naproxen or any NSAID; history of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs; perioperative pain in the setting of CABG surgery; active gastrointestinal bleeding; advanced renal disease.

Clinical Precautions

Precautions

Cardiovascular risk (increased risk of MI and stroke); gastrointestinal risk (bleeding, ulceration, perforation); renal toxicity; hepatic impairment; asthma exacerbation; fluid retention; hypertension; anaphylactoid reactions; pregnancy (avoid in third trimester).

Clinical Tips & Counseling

Drug interactions

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NAPRELAN

Clinical safety rating: caution

Comprehensive clinical and safety monograph for NAPRELAN (NAPRELAN).

How it works

Nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis, which mediates pain, inflammation, and fever.

What the body does with it

Metabolism	Primarily hepatic via CYP1A2 and CYP2C9; minor metabolism via glucuronidation and other pathways.
Excretion	Renal: 50-60% as metabolites and conjugates; biliary/fecal: ~5%; remainder uncharacterized.
Half-life	Terminal elimination half-life: 10-20 hours; context: allows twice-daily or once-daily dosing for chronic pain or inflammation.
Protein binding	>99% bound, primarily to albumin.
Volume of Distribution	0.16 L/kg; clinical meaning: low Vd indicates limited tissue distribution, predominantly in plasma.
Bioavailability	Oral (conventional): ~95%; NAPRELAN: approximately 85% of conventional naproxen (due to controlled-release matrix).
Onset of Action	Oral: 1-2 hours (as conventional tablet); NAPRELAN (controlled-release): 2-4 hours.
Duration of Action	12-24 hours; clinical note: NAPRELAN formulation provides sustained plasma levels for twice-daily dosing.

Classification & Brands

Dosing & administration

750 mg to 1000 mg orally once daily, with or without food.

Dosage form	TABLET, EXTENDED RELEASE
Renal impairment	CrCl <30 mL/min: avoid use; CrCl 30-59 mL/min: reduce dose to 500 mg once daily or use alternative.
Liver impairment	Child-Pugh Class B or C: reduce dose to 500 mg once daily or avoid use; monitor for toxicity.
Pediatric use	Not established for children under 18 years; safety and efficacy not determined.
Geriatric use	Initiate at lowest effective dose (e.g., 500 mg once daily); monitor renal function and adjust as needed.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for NAPRELAN (NAPRELAN).

Breastfeeding	Naproxen is excreted into breast milk in small amounts; M/P ratio is approximately 0.01. The American Academy of Pediatrics considers it compatible with breastfeeding, but caution is advised, especially in preterm infants or neonates with compromised renal function. Monitor infant for drowsiness, poor feeding, or jaundice.
Teratogenic Risk	Naproxen (NAPRELAN) is contraindicated in the third trimester due to risk of premature closure of ductus arteriosus and oligohydramnios. In first and second trimesters, use only if clearly needed; limited data suggest possible association with spontaneous abortion and cardiac defects, but absolute risk is low.