Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CARISOPRODOL COMPOUND vs IPLEX
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Carisoprodol is a centrally acting muscle relaxant that acts as a prodrug for meprobamate, a barbiturate-like compound with sedative and anxiolytic properties. Its mechanism is thought to involve GABA-A receptor modulation and depression of polysynaptic reflexes in the spinal cord and reticular formation. Aspirin provides analgesic and anti-inflammatory effects via irreversible inhibition of cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis. Codeine is an opioid agonist at mu-opioid receptors, producing analgesia by mimicking endogenous endorphins.
IPLEX (mecasermin rinfabate) is a complex of recombinant human insulin-like growth factor-1 (IGF-1) and its binding protein (IGFBP-3). It activates the IGF-1 receptor, promoting linear growth by stimulating chondrocyte proliferation in epiphyseal growth plates, as well as exerting anabolic effects on muscle and other tissues.
Relief of discomfort associated with acute, painful musculoskeletal conditions,As an adjunct to rest, physical therapy, and other measures
FDA: Treatment of growth failure in children with severe primary IGF-1 deficiency (e.g., Laron syndrome, GH gene deletion, GH receptor defects) or with neutralizing antibodies to GH.,Off-label: Treatment of insulin-like growth factor-1 deficiency in adults; investigational in ALS and other neurodegenerative disorders.
1-2 tablets (carisoprodol 200 mg/aspirin 325 mg) orally 4 times daily.
0.5-2 mg/kg subcutaneously once daily, titrated based on IGF-I levels.
Carisoprodol has a terminal elimination half-life of approximately 1.5–2 hours; its active metabolite meprobamate has a half-life of 9–12 hours, which may lead to prolonged effects with chronic use.
Terminal elimination half-life of 10-12 hours after subcutaneous administration, supporting twice-daily dosing.
Carisoprodol is metabolized by CYP2C19 to meprobamate (active metabolite). Aspirin is hydrolyzed by esterases in the liver and plasma to salicylic acid, which is further conjugated. Codeine is metabolized by CYP2D6 to morphine (active) and by CYP3A4 to norcodeine.
Mecasermin (IGF-1) is metabolized by proteolytic degradation into amino acids; IGFBP-3 is also proteolytically degraded. No significant cytochrome P450 metabolism.
Carisoprodol is primarily metabolized in the liver, with about 50% excreted renally as unchanged drug and metabolites; the major metabolite meprobamate is also renally excreted. Fecal excretion is negligible (<2%).
Renal excretion of intact IGF-I and its metabolites; approximately 70% eliminated via kidneys, with 30% biliary/fecal.
Carisoprodol is approximately 60% bound to plasma proteins, mainly albumin.
Approximately 90% bound to IGF-binding proteins (IGFBPs), primarily IGFBP-3, and a minor fraction to albumin.
Volume of distribution is approximately 0.6–0.8 L/kg, indicating distribution into total body water.
Vd approximately 0.25-0.30 L/kg, indicating distribution primarily to extracellular fluid and well-perfused tissues.
Oral bioavailability is nearly complete (close to 100%) due to rapid and extensive absorption.
Subcutaneous: Approximately 80-100%.
Contraindicated in severe renal impairment (Cr Cl <30 m L/min). No specific dose adjustment for mild-moderate impairment; use caution.
Contraindicated in severe renal impairment (Cr Cl <30 m L/min). For moderate impairment (Cr Cl 30–50 m L/min), reduce dose by 25%; monitor IGF-I closely.
Contraindicated in severe hepatic impairment (Child-Pugh class C). For moderate impairment, reduce dose or increase interval; specific guidelines not established.
Not studied in hepatic impairment; use with caution in Child-Pugh B or C; consider dose reduction based on clinical response and IGF-I monitoring.
Not recommended for pediatric patients due to aspirin content and risk of Reye syndrome.
0.5-2 mg/kg subcutaneously once daily, titrated to achieve age-appropriate IGF-I levels.
Initiate at lowest effective dose; monitor for CNS depression, falls, and aspirin-related bleeding. Avoid in patients ≥65 years due to risks of dizziness, sedation, and GI bleeding.
No specific dose adjustment; initiate at lower end of dosing range (0.5 mg/kg/day) due to potential for decreased renal function and increased sensitivity.
None
Not available (no FDA boxed warning as of current labeling).
Risk of dependence, abuse, and withdrawal with carisoprodol and codeine,CYP2D6 ultrarapid metabolizers may have morphine toxicity from codeine,Reye's syndrome risk in children with viral illness (aspirin),GI bleeding risk with aspirin,Respiratory depression with codeine,Sedation and impaired motor function,Hepatic impairment,Renal impairment
Hypoglycemia (especially in fasted state), intracranial hypertension, slipped capital femoral epiphysis, lymphatic tissue hypertrophy (e.g., tonsillar/adenoid enlargement), allergic reactions, and progression of pre-existing malignancies. Injection site reactions, lipohypertrophy. Risk of hyperglycemia if used in patients with diabetes. Monitor blood glucose, fundoscopy for papilledema, and for signs of hip/knee pain.
Hypersensitivity to carisoprodol, meprobamate, aspirin, codeine, or any component,Porphyria,Acute intermittent porphyria,Children with viral illness (aspirin) due to Reye's syndrome risk,Breastfeeding (codeine),Severe renal or hepatic impairment,GI bleeding or peptic ulcer disease (aspirin),Concurrent use of MAOIs or within 14 days,Respiratory depression (codeine)
Hypersensitivity to mecasermin rinfabate or any component; active or suspected neoplasia; epiphyseal closure (skeletal maturity); children with closed epiphyses (except if indicated for severe IGF-1 deficiency with open epiphyses).
Avoid alcohol and grapefruit juice. Alcohol increases CNS depression and risk of hepatotoxicity. Grapefruit juice may inhibit metabolism, leading to increased levels and toxicity.
No specific food interactions reported. However, to minimize hypoglycemia risk, IPLEX should be administered immediately after a meal or snack. Avoid prolonged fasting. Alcohol use may increase hypoglycemia risk; avoid or limit alcohol consumption.
Carisoprodol is a pregnancy category C drug. Data from animal studies are insufficient or show adverse effects, but no adequate human studies exist. There is a potential risk of fetal harm if used during the first trimester due to possible neural tube defects based on limited reports. In the second and third trimesters, maternal use may cause neonatal withdrawal symptoms (e.g., irritability, feeding difficulties) and respiratory depression if used near term. Carisoprodol is not recommended during pregnancy unless benefit outweighs risk.
IPLEX (mecasermin rinfabate) is a recombinant human insulin-like growth factor-1 (IGF-1) complexed with IGF-binding protein-3. There are no adequate and well-controlled studies in pregnant women. In animal studies, administration of IGF-1 during organogenesis resulted in fetal growth retardation and increased skeletal abnormalities at doses similar to human exposure. Due to its growth-promoting effects, potential for teratogenicity, and interference with normal fetal development, IPLEX is contraindicated during pregnancy. First trimester: Risk of skeletal and growth abnormalities. Second and third trimesters: continued risk of abnormal fetal growth and development, including organ overgrowth or underdevelopment. Use only if maternal benefits outweigh potential fetal risks; however, generally avoided.
Carisoprodol is excreted into human breast milk. The milk-to-plasma (M/P) ratio is approximately 2-4 based on small studies. An infant would receive a weight-adjusted dose of about 4-8% of the maternal dose, which may cause sedation, drowsiness, or irritability in the neonate. Breastfeeding is not recommended during carisoprodol use, especially in premature infants or those with hepatic impairment. If used, monitor infant for signs of CNS depression.
It is unknown whether mecasermin rinfabate or its components (IGF-1, IGFBP-3) are excreted in human milk. Due to the potential for serious adverse reactions in the nursing infant, including growth stimulation and hypoglycemia, breast-feeding is not recommended during IPLEX therapy. No M/P ratio is available.
No specific dosing adjustments for carisoprodol are established in pregnancy. However, due to increased plasma volume and altered hepatic metabolism in pregnancy, the drug's half-life may be reduced. Clinical monitoring for efficacy and maternal side effects (e.g., drowsiness, dizziness) is recommended. Use the lowest effective dose for the shortest duration. Consider avoidance of the compound formulation with aspirin or other NSAIDs, which have additional risks.
No specific pharmacokinetic studies of IPLEX in pregnancy are available. The physiological changes of pregnancy (increased plasma volume, altered renal function, increased hepatic metabolism) may affect clearance of mecasermin rinfabate; however, due to its contraindication, dose adjustments during pregnancy are not recommended. If absolutely necessary, use the lowest effective dose and monitor for efficacy and adverse effects. No established dose adjustment guidelines exist.
Carisoprodol is metabolized to meprobamate, a controlled substance with abuse potential; use cautiously in patients with history of substance abuse. Combination with other CNS depressants (e.g., alcohol, benzodiazepines) increases sedation risk. Limit use to 2-3 weeks due to lack of efficacy beyond that and risk of dependence. Avoid in patients with porphyria because carisoprodol may be porphyrinogenic.
IPLEX (mecasermin rinfabate) is a complex of recombinant human insulin-like growth factor-1 (rh IGF-1) and its binding protein (rh IGFBP-3). It is indicated for growth failure in children with severe primary IGF-1 deficiency (e.g., Laron syndrome) or with GH gene deletion who have developed neutralizing antibodies to GH. Administer subcutaneously; dose is based on IGF-1 levels. Monitor for hypoglycemia, especially after injection; patients should eat shortly after dosing. Do not use in patients with closed epiphyses or active neoplasia. May cause lymphoproliferative disorders; monitor for splenomegaly, lymphadenopathy.
This medication may cause drowsiness, dizziness, or blurred vision; avoid driving or operating machinery until you know how it affects you.,Do not consume alcohol or other CNS depressants while taking this drug.,Take only as prescribed; do not increase dose or frequency. This drug has abuse potential.,Inform your doctor if you have a history of drug or alcohol abuse, seizures, or liver/kidney disease.,Do not use for longer than 2-3 weeks unless directed by your doctor.
Inject IPLEX within 20 minutes after a meal or snack to prevent hypoglycemia.,Rotate injection sites (abdomen, thigh, upper arm) to avoid lipohypertrophy.,Report symptoms of hypoglycemia (shakiness, sweating, confusion) or increased growth velocity.,Keep a log of blood glucose levels if advised by your doctor.,Store IPLEX in the refrigerator (2-8°C); do not freeze. Protect from light.,Do not share needles or pens; dispose of used needles in a sharps container.,Continue regular follow-up appointments for growth monitoring and blood tests.
"The co-administration of pentobarbital, a barbiturate and potent CYP3A4 inducer, with carisoprodol, a prodrug that is metabolized to its active form, meprobamate, via CYP2C19, may lead to reduced plasma concentrations of meprobamate due to pentobarbital-induced upregulation of CYP2C19, potentially diminishing the sedative and muscle relaxant effects of carisoprodol. However, pentobarbital also acts as a central nervous system (CNS) depressant, and additive CNS depression can occur, increasing the risk of excessive sedation, respiratory depression, and impairment of psychomotor function. Clinical outcomes may include altered therapeutic efficacy of carisoprodol and heightened risk of CNS and respiratory adverse effects."
"Carisoprodol, a centrally acting skeletal muscle relaxant, is metabolized primarily by CYP2C19 to its active metabolite meprobamate. Isoniazid, a first-line antitubercular agent, is a known inhibitor of CYP2C19. When coadministered, isoniazid can decrease the metabolism of carisoprodol, leading to increased plasma concentrations of both carisoprodol and meprobamate. This elevation raises the risk of dose-related adverse effects such as sedation, dizziness, and respiratory depression, and may prolong the duration of muscle relaxant action."
"The combination of sulpiride, an atypical antipsychotic with dopamine D2 receptor antagonism and mild serotonin 5-HT4 agonist properties, and carisoprodol, a centrally acting muscle relaxant metabolized to meprobamate (a barbiturate-like sedative-hypnotic), can result in additive central nervous system (CNS) depression, including sedation, dizziness, and psychomotor impairment. Additionally, both drugs may lower the seizure threshold, increasing the risk of seizures. Sulpiride can also prolong the QT interval, and carisoprodol's sedative effects may mask or exacerbate this cardiotoxicity, potentially leading to ventricular arrhythmias such as torsade de pointes."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about CARISOPRODOL COMPOUND vs IPLEX, answered by our medical review team.
CARISOPRODOL COMPOUND is a Skeletal Muscle Relaxant that works by Carisoprodol is a centrally acting muscle relaxant that acts as a prodrug for meprobamate, a barbiturate-like compound with sedative and anxiolytic properties. Its mechanism is thought to involve GABA-A receptor modulation and depression of polysynaptic reflexes in the spinal cord and reticular formation. Aspirin provides analgesic and anti-inflammatory effects via irreversible inhibition of cyclooxygenase (COX-1 and COX-2), reducing prostaglandin synthesis. Codeine is an opioid agonist at mu-opioid receptors, producing analgesia by mimicking endogenous endorphins.. IPLEX is a Growth Factor that works by IPLEX (mecasermin rinfabate) is a complex of recombinant human insulin-like growth factor-1 (IGF-1) and its binding protein (IGFBP-3). It activates the IGF-1 receptor, promoting linear growth by stimulating chondrocyte proliferation in epiphyseal growth plates, as well as exerting anabolic effects on muscle and other tissues.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CARISOPRODOL COMPOUND and IPLEX depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of CARISOPRODOL COMPOUND is: 1-2 tablets (carisoprodol 200 mg/aspirin 325 mg) orally 4 times daily.. The standard adult dose of IPLEX is: 0.5-2 mg/kg subcutaneously once daily, titrated based on IGF-I levels.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between CARISOPRODOL COMPOUND and IPLEX in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. CARISOPRODOL COMPOUND is classified as Category A/B. Carisoprodol is a pregnancy category C drug. Data from animal studies are insufficient or show adverse effects, but no adequate human studies exist. There is a potential risk of fe. IPLEX is classified as Category C. IPLEX (mecasermin rinfabate) is a recombinant human insulin-like growth factor-1 (IGF-1) complexed with IGF-binding protein-3. There are no adequate and well-controlled studies in . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.