PROPACET 100
Clinical safety rating
cautionComprehensive clinical and safety monograph for PROPACET 100 (PROPACET 100).
Propacet 100 is a prodrug of acetaminophen; it is hydrolyzed to acetaminophen, which inhibits cyclooxygenase (COX) and modulates the endogenous cannabinoid system, leading to analgesic and antipyretic effects.
| Metabolism | Rapidly hydrolyzed by plasma esterases to acetaminophen; acetaminophen is primarily metabolized by glucuronidation and sulfation, with a minor pathway via CYP2E1 to the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI). |
| Excretion | Propacet 100 (propacetamol) is a prodrug of acetaminophen. Renal elimination accounts for >90% of the administered dose, with approximately 85% as acetaminophen glucuronide and sulfate conjugates, and about 5% as unchanged acetaminophen. Biliary/fecal elimination is minimal (<5%). |
| Half-life | The terminal elimination half-life of acetaminophen after propacetamol administration is approximately 2–3 hours in adults with normal hepatic function. This half-life may be prolonged in patients with hepatic impairment or overdose. |
| Protein binding | Acetaminophen is minimally bound to plasma proteins, with protein binding of approximately 10–25% at therapeutic concentrations. It binds primarily to albumin. |
| Volume of Distribution | The volume of distribution (Vd) of acetaminophen is approximately 0.9–1.0 L/kg, indicating distribution into total body water. This reflects its hydrophilic nature and widespread tissue penetration. |
| Bioavailability | Propacetamol is administered intravenously; thus, bioavailability is 100%. After hydrolysis to acetaminophen, the bioavailability of active acetaminophen is essentially complete. |
| Onset of Action | Intravenous administration: Onset of analgesia occurs within 5–10 minutes after the start of infusion. Peak effect is observed at approximately 1 hour. |
| Duration of Action | Duration of analgesia is approximately 4–6 hours following intravenous administration. Clinical effect correlates with plasma acetaminophen concentrations above therapeutic threshold. |
| Molecular Weight | 151.16 |
1-2 tablets (100-200 mg propacetamol) orally every 4-6 hours; maximum 8 tablets (800 mg) per day.
| Dosage form | TABLET |
| Renal impairment | GFR 30-50 mL/min: extend interval to every 8 hours; GFR <30 mL/min: extend interval to every 12 hours; hemodialysis: dose post-dialysis. |
| Liver impairment | Child-Pugh class A: no adjustment; Child-Pugh class B: reduce dose by 50%; Child-Pugh class C: use alternative analgesic. |
| Pediatric use | 10-15 mg/kg/dose propacetamol equivalent every 6 hours; maximum 60 mg/kg/day; do not exceed adult dose. |
| Geriatric use | Initiate at lower end of dosing range (100 mg every 6 hours); maximum 800 mg/day; monitor renal and hepatic function. |
| 1st trimester | Avoid. Epidemiologic studies suggest an increased risk of miscarriage and congenital malformations (cardiac, orofacial clefts) with first trimester exposure. |
| 2nd trimester | Use with caution. Potential for oligohydramnios and fetal renal impairment with prolonged use; avoid higher doses and long-term therapy. |
| 3rd trimester | Avoid. Associated with premature closure of the ductus arteriosus, oligohydramnios, and neonatal renal impairment; may inhibit labor and increase risk of periventricular hemorrhage. |
Clinical note
Comprehensive clinical and safety monograph for PROPACET 100 (PROPACET 100).
| Placental transfer | Transfers across placenta; fetal serum concentrations may approach maternal levels. |
| Breastfeeding | Excreted into breast milk in low amounts; however, because of potential adverse effects in the infant (e.g., Reye syndrome, Kernicterus), caution is advised; consider alternative analgesics, particularly in G6PD deficiency or if infant is < 3 months old. |
| Lactation Rating | L2 (Safer) when used at recommended doses, but avoid prolonged high-dose therapy. |
| Teratogenic Risk | Propacet 100 (propacetamol) is a prodrug of paracetamol (acetaminophen). First trimester: Limited human data, no increased risk of major malformations in large cohort studies. Second and third trimesters: No known fetal toxicity at therapeutic doses; overdose may cause hepatic necrosis in mother and potentially fetus. |
| Fetal Monitoring | Monitor maternal liver function tests (ALT, AST) if prolonged use or overdose suspected. For chronic or high-dose use, assess fetal growth via ultrasound. No specific fetal monitoring required for short-term therapeutic doses. |
| Fertility Effects | No known adverse effects on human fertility. Animal studies show no impairment of fertility at clinical doses. |
■ FDA Black Box Warning
No FDA black box warning exists for propacetamol specifically; however, acetaminophen (active metabolite) carries a risk of severe liver injury in cases of overdose, particularly with chronic alcohol use or hepatic impairment.
| Serious Effects |
Severe hepatic impairment or active liver diseaseHypersensitivity to propacetamol or other NSAIDs (aspirin-sensitive asthma)Third trimester of pregnancySevere renal impairment (eGFR <30 mL/min)Active peptic ulcer disease or gastrointestinal bleeding
| Precautions | Hepatotoxicity risk with overdose or chronic alcohol use; severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis) reported rarely; use with caution in hepatic impairment, alcohol use disorder, or malnutrition. |
| Food/Dietary | No specific food interactions; however, maintain adequate caloric intake to support glutathione synthesis. Avoid alcohol as it may increase hepatotoxicity risk. |
| Clinical Pearls | Propacet 100 (propacetamol, a prodrug of acetaminophen) is administered intravenously; ensure patency of IV line to prevent extravasation, which can cause injection site reactions. Contraindicated in severe hepatic impairment (Child-Pugh C) and in patients with glutathione depletion (e.g., malnutrition, sepsis). Monitor liver function tests during prolonged use. Use with caution in patients with asthma, as sulfite in formulation may trigger bronchospasm. |
| Patient Advice | Propacet 100 is given intravenously for pain or fever; you must receive it in a healthcare setting. · Report any signs of allergic reaction such as rash, itching, swelling, or trouble breathing immediately. · This medication is a prodrug of acetaminophen; do not take additional acetaminophen-containing products while on this therapy. · Avoid alcohol during treatment to reduce risk of liver damage. |
Loading safety data…