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Opioid Analgesic/Discontinued

CONZIP

CONZIP

Clinical safety rating

caution

Comprehensive clinical and safety monograph for CONZIP (CONZIP).


Mechanism of Action

Tramadol hydrochloride (opioid agonist) and acetaminophen (centrally acting analgesic). Tramadol binds to mu-opioid receptors and inhibits serotonin and norepinephrine reuptake; acetaminophen inhibits cyclooxygenase (COX) and activates descending serotonergic pathways.

What the body does with it

MetabolismTramadol: hepatic via CYP2D6 and CYP3A4 to active M1 metabolite; acetaminophen: hepatic via conjugation (glucuronidation, sulfation) and CYP2E1 (minor).
Excretion~60% renal (unchanged drug and glucuronide conjugates), ~35% fecal
Half-lifeTerminal elimination half-life: 3-4 hours for tramadol, 5-9 hours for M1 metabolite; clinically, dosing interval is 4-6 hours
Protein binding~20% bound to plasma proteins (primarily albumin)
Volume of Distribution3.9 L/kg (tramadol), indicating extensive tissue distribution
BioavailabilityOral: 75% (immediate-release); extended-release: ~100% relative to immediate-release
Onset of ActionOral: 1 hour (immediate-release); extended-release: 2 hours
Duration of ActionOral immediate-release: 4-6 hours; extended-release: 12-24 hours (up to 24 hours with CONZIP ER)
Molecular Weight327.8

Classification & Brands

Action ClassFungal ergosterol synthesis inhibitor
Brand SubstitutesFluent 150mg Tablet, Odicon 150 Tablet, Gocan 150mg Tablet, Fluka 150 Tablet, Fusys 150 Tablet

Dosing & administration

100 mg to 300 mg orally once daily with food. Initiate at 100 mg daily and titrate up by 100 mg increments every 4-7 days based on tolerability. Maximum dose 300 mg daily.

Dosage formCAPSULE, EXTENDED RELEASE
Renal impairmentFor creatinine clearance (CrCl) 60-89 mL/min: no adjustment. For CrCl 30-59 mL/min: reduce dose by 30% (e.g., start 70 mg daily). For CrCl 15-29 mL/min: reduce dose by 50% (e.g., start 50 mg daily). For CrCl <15 mL/min: not recommended. Hemodialysis: administer dose after dialysis on dialysis days; reduce dose by 70%.
Liver impairmentFor Child-Pugh Class A (mild): no adjustment. For Child-Pugh Class B (moderate): reduce dose by 50% (e.g., start 50 mg daily). For Child-Pugh Class C (severe): not recommended (or maximum 50 mg daily with caution).
Pediatric useSafety and efficacy not established in pediatric patients (<18 years). No recommended dosage.
Geriatric useFor patients ≥65 years: initiate at 100 mg daily. Use caution and monitor for confusion and sedation. Consider reducing dose to 50 mg daily if tolerability issues arise.

Use during pregnancy

1st trimesterNo adequate studies; avoid use unless benefit outweighs risk. Teratogenic effects not confirmed but caution advised.
2nd trimesterLimited data; use only if clearly needed. Monitor fetal growth and well-being.
3rd trimesterAvoid use near term due to risk of neonatal respiratory depression and withdrawal syndrome.

Clinical note

Comprehensive clinical and safety monograph for CONZIP (CONZIP).

Placental transferCrosses placenta; degree unknown but expected due to low molecular weight.
BreastfeedingExcreted into human milk in low concentrations, but potential for infant sedation. American Academy of Pediatrics recommends caution. Monitor infant for drowsiness, poor feeding, and respiratory depression.
Lactation RatingL3 (Moderately Safe)
Teratogenic RiskCONZIP (tramadol hydrochloride) is FDA Pregnancy Category C. In first trimester, cross-reactivity with opioid receptors raises concern for neural tube defects based on animal studies; human data limited but not excluded. In second and third trimesters, prolonged use may cause fetal opioid dependence and neonatal abstinence syndrome (NAS). Near term, use may lead to respiratory depression in the neonate.
Fetal MonitoringMonitor maternal respiratory rate, sedation level, and bowel function. Fetal monitoring: non-stress test (NST) and biophysical profile (BPP) if prolonged use or signs of withdrawal. Neonatal monitoring for respiratory depression, sedation, and NAS (especially with chronic use).
Fertility EffectsTramadol may impair female fertility via prolactin elevation or direct effects on ovarian steroidogenesis, as suggested by animal studies. Human data limited; men may experience reduced libido or erectile dysfunction. Effects are typically reversible upon discontinuation.

Warnings & precautions

■ FDA Black Box Warning

Addiction, abuse, and misuse; life-threatening respiratory depression; accidental ingestion (especially in children); ultra-rapid metabolism of tramadol to O-desmethyltramadol (M1) in CYP2D6 poor metabolizers leading to toxicity; neonatal opioid withdrawal syndrome with prolonged use during pregnancy; risks from concomitant use with benzodiazepines or other CNS depressants.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to tramadol or any component of CONZIPAcute intoxication with alcohol, hypnotics, opioids, or psychotropic drugsSevere respiratory depression including in acute asthma or COPDConcurrent use of MAO inhibitors or within 14 days of discontinuationSeizure disorderSignificant risk of serotonin syndrome (e.g., SSRIs, SNRIs, TCAs)

Clinical Precautions

PrecautionsRespiratory depression; seizure risk (especially with CNS depressants, MAOIs, SSRIs, SNRIs); serotonin syndrome; increased intracranial pressure; severe hypotension; head injury; acute abdominal conditions; renal/hepatic impairment; elderly; debilitated patients; drug dependence; withdrawal; pregnancy; nursing mothers; CYP2D6 ultrarapid metabolizers; concomitant use with alcohol or other CNS depressants.
Food/DietaryGrapefruit and grapefruit juice may increase tramadol levels by inhibiting CYP3A4 metabolism. Avoid excessive caffeine as it may increase seizure risk. Food does not significantly affect absorption; may be taken with or without food.

Clinical Tips & Counseling

Clinical PearlsCONZIP (tramadol hydrochloride) is a centrally acting opioid analgesic with additional serotonin and norepinephrine reuptake inhibition. It has a lower risk of respiratory depression compared to typical opioids but carries risks of seizures, especially in patients with epilepsy, head trauma, or those taking SSRIs, SNRIs, or MAOIs. CYP2D6 poor metabolizers may have reduced efficacy. Do not exceed 400 mg/day (300 mg in elderly >75 years). Avoid sudden discontinuation to prevent withdrawal syndrome.
Patient AdviceTake exactly as prescribed; do not increase dose or frequency without consulting your doctor. · Avoid alcohol, sedatives, and other CNS depressants as they increase risk of severe drowsiness and respiratory depression. · Do not stop suddenly; taper dose under medical supervision to prevent withdrawal symptoms. · May cause dizziness or drowsiness; avoid driving or operating machinery until you know how you react. · Risk of serotonin syndrome when combined with other serotonergic drugs; report symptoms like agitation, high fever, or muscle twitching. · If you have a history of seizures, inform your doctor; tramadol may lower seizure threshold. · Swallow tablets whole; do not crush, chew, or split extended-release tablets. · Store in original container away from moisture and heat.

CONZIP Interactions

Loading safety data…

This overview is compiled from peer-reviewed clinical sources and FDA labeling. It's here to support — not replace — clinical judgment. Always verify dosing against your institution's current protocols before prescribing.

On this page

Mechanism of ActionDosing & administrationUse during pregnancyWarnings & precautionsDrug interactions

Compare with

ABSTRALACEPHENACTIQALFENTAALFENTANIL

External sources

DailyMed (NIH) PubMed OpenFDA