MEASURIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MEASURIN (MEASURIN).
Measurin is an aspirin preparation that irreversibly inhibits cyclooxygenase (COX-1 and COX-2), thereby reducing prostaglandin and thromboxane synthesis. This results in analgesic, antipyretic, anti-inflammatory, and antiplatelet effects.
| Metabolism | Measurin is rapidly hydrolyzed to salicylic acid in the gastrointestinal tract and liver. Salicylic acid is primarily metabolized in the liver via conjugation with glycine (to form salicyluric acid) and glucuronic acid, and oxidation to gentisic acid and other metabolites. Major enzymes: UGTs, CYP2E1 (minor). |
| Excretion | Renal excretion of salicylate and its metabolites (salicyluric acid, salicyl phenolic glucuronide, salicyl acyl glucuronide, gentisic acid) accounts for >90% of elimination; minor biliary/fecal excretion (<5%) occurs. |
| Half-life | Plasma elimination half-life is 2-3 hours at low doses (antiplatelet) and increases to 15-30 hours at anti-inflammatory doses due to saturation of hepatic metabolism; clinical context: higher doses require longer dosing intervals to avoid accumulation. |
| Protein binding | Highly bound to albumin (80-90%); binding is saturable at high concentrations. |
| Volume of Distribution | 0.1-0.2 L/kg; low Vd indicates limited extravascular distribution; increased in acidosis or hypoalbuminemia. |
| Bioavailability | Oral: 80-100% (immediate-release); delayed-release forms have reduced rate but complete extent of absorption. |
| Onset of Action | Oral: Analgesic effect begins 30-60 minutes; anti-inflammatory effect begins 1-2 hours; antiplatelet effect occurs within 1 hour (irreversible COX-1 inhibition). |
| Duration of Action | Analgesic/antipyretic: 3-4 hours; anti-inflammatory: up to 12 hours; antiplatelet: 7-10 days (lifespan of platelet). |
| Molecular Weight | 180.16 |
325-650 mg orally every 4-6 hours as needed; maximum 4 g/day.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | GFR 10-50 mL/min: avoid use or extend dosing interval to 6-8 hours; GFR <10 mL/min: contraindicated. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50% and monitor; Child-Pugh C: contraindicated. |
| Pediatric use | 10-15 mg/kg/dose orally every 4-6 hours; maximum 75 mg/kg/day or 4 g/day. |
| Geriatric use | Initiate at lowest effective dose; consider 325 mg every 6-8 hours due to increased risk of GI bleeding and renal impairment. |
| 1st trimester | Risk of miscarriage and congenital malformations; avoid if possible. May cause premature closure of ductus arteriosus and oligohydramnios. |
| 2nd trimester | Avoid due to risk of premature closure of ductus arteriosus and oligohydramnios. |
| 3rd trimester | Contraindicated in third trimester due to increased risk of premature closure of ductus arteriosus and oligohydramnios. |
Clinical note
Comprehensive clinical and safety monograph for MEASURIN (MEASURIN).
| Placental transfer | Crosses placenta; extent of transfer is significant, with fetal concentrations reaching similar levels to maternal. |
| Breastfeeding | Enters breast milk in low concentrations; adverse effects in infants are rare but monitor for rash, bleeding, or drowsiness. Use with caution. |
■ FDA Black Box Warning
Reye's syndrome: Aspirin should not be used in children or teenagers with viral infections because of the risk of Reye's syndrome.
| Serious Effects |
Active peptic ulcer diseaseHemophilia or bleeding disordersHypersensitivity to NSAIDsSevere renal impairmentThird trimester pregnancy
| Precautions | Risk of gastrointestinal bleeding, ulcers, and perforation; increased bleeding risk (especially with alcohol, anticoagulants); Reye's syndrome in children with viral illness; hypersensitivity reactions including asthma and anaphylaxis; impaired renal function; avoid use during late pregnancy (may cause premature closure of ductus arteriosus and increase risk of hemorrhage). |
| Food/Dietary | Avoid alcohol. Taking with food may reduce GI irritation. High-fat meals may delay absorption; take consistently with meals. |
Loading safety data…
| Lactation Rating |
| L2 (Safer) |
| Teratogenic Risk | Measurin (aspirin) is contraindicated in the third trimester due to risk of premature closure of ductus arteriosus and oligohydramnios. In first and second trimesters, increased risk of gastroschisis and cardiac defects. Avoid high doses near term. |
| Fetal Monitoring | Monitor fetal ultrasound for ductus arteriosus flow and amniotic fluid index. Maternal bleeding time, platelet count, and signs of gastrointestinal bleeding. Neonatal monitoring for bruising and bleeding. |
| Fertility Effects | Aspirin may inhibit prostaglandin synthesis, potentially delaying ovulation or impairing implantation. Reversible effect. |
| Clinical Pearls | Measurin is an extended-release formulation of aspirin (acetylsalicylic acid) designed for once-daily dosing. It should not be crushed or chewed. Monitor for signs of GI bleeding, especially in elderly patients or those on anticoagulants. Reye syndrome risk in children with viral infections. |
| Patient Advice | Take with a full glass of water and food to reduce stomach upset. · Swallow whole; do not crush, chew, or break the tablet. · Avoid alcohol while taking this medication. · Do not use in children or teenagers with viral infections due to Reye syndrome risk. · Seek medical help if you experience ringing in the ears, bloody stools, or easy bruising. |