DIACOMIT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DIACOMIT (DIACOMIT).
Stiripentol is an anticonvulsant that potentiates GABAergic neurotransmission by acting as a positive allosteric modulator of GABA-A receptors and inhibiting GABA transaminase. It also inhibits CYP2C19 and other cytochrome P450 enzymes, thereby increasing plasma concentrations of concomitant antiepileptic drugs like clobazam.
| Metabolism | Extensively metabolized in the liver, primarily via CYP2C19 and CYP3A4; forms glucuronide conjugates. |
| Excretion | Primarily renal excretion: 50% as unchanged drug, 30% as glucuronide conjugate, 20% via fecal/biliary routes. |
| Half-life | Terminal elimination half-life: 13-20 hours; in severe renal impairment (CrCl <30 mL/min), half-life prolonged to 40-60 hours. Requires dose adjustment. |
| Protein binding | 93-97% bound to serum albumin. |
| Volume of Distribution | 0.7-1.0 L/kg; distributes into total body water, with extensive extravascular distribution. |
| Bioavailability | Oral: 85-90% (absolute bioavailability after oral administration). |
| Onset of Action | Oral: 1-2 hours to peak plasma concentration; clinical effect on seizure frequency typically observed within 1-2 weeks of therapeutic dosing. |
| Duration of Action | 12-24 hours due to twice-daily dosing; trough levels must be maintained >4 mcg/mL for efficacy. Duration may be shorter in patients with rapid metabolism. |
| Molecular Weight | 212.25 |
10 mg/kg/day orally in two divided doses; increase weekly by 10 mg/kg/day to 70 mg/kg/day or 3 g/day, whichever is lower.
| Dosage form | CAPSULE |
| Renal impairment | Not recommended in patients with severe renal impairment (CrCl < 30 mL/min). For mild to moderate impairment (CrCl 30-89 mL/min), use with caution and monitor for adverse effects; no specific dose adjustment established. |
| Liver impairment | Contraindicated in patients with severe hepatic impairment (Child-Pugh class C). For moderate impairment (Child-Pugh class B), reduce initial dose by 50% and titrate slowly. For mild impairment (Child-Pugh class A), no adjustment required. |
| Pediatric use | Children aged 1-18 years: 10 mg/kg/day orally in two divided doses; increase weekly by 10 mg/kg/day to 70 mg/kg/day or 3 g/day, whichever is lower. |
| Geriatric use | Initiate at low end of dosing range due to possible reduced renal function and increased sensitivity; monitor renal function and adjust dose accordingly. |
| 1st trimester | Avoid due to teratogenic risk (neural tube defects, cardiac malformations). Potential for embryo-fetal toxicity observed in animal studies. |
| 2nd trimester | Use only if benefit outweighs risk. Monitor for fetal growth restriction and malformations. |
| 3rd trimester | Use only if benefit outweighs risk. Risk of hemorrhagic disease in newborn (vitamin K deficiency). Administer vitamin K to neonate. |
Clinical note
Comprehensive clinical and safety monograph for DIACOMIT (DIACOMIT).
| Placental transfer | Crosses placenta (100% transfer in animal studies; human data limited but substantial transfer expected due to low molecular weight and lipophilicity). |
| Breastfeeding | Excreted into breast milk in low amounts; monitor infant for drowsiness, poor feeding, or jaundice. Consider alternative if possible. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to stiripentol or any componentPorphyriaSevere hepatic impairmentHistory of psychosis or confusion with stiripentol
| Precautions | Somnolence and dizziness, particularly when used with clobazam, Neutropenia and thrombocytopenia, Risk of suicidal thoughts and behavior, Drug interactions due to CYP inhibition, especially with clobazam and valproate, Monitor for weight loss and growth retardation in children, Hyperammonemia when used with valproate |
| Food/Dietary | Avoid food or milk within 1 hour before or after dose; food increases absorption and risk of adverse effects. Grapefruit may increase drug levels. |
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| Lactation Rating |
| L3 (Moderately Safe) |
| Teratogenic Risk | Diacomit (stiripentol) is classified as FDA Pregnancy Category D. There is positive evidence of human fetal risk based on animal reproduction studies and human data. First trimester exposure may be associated with major congenital malformations including cardiac defects and neural tube defects. In the second and third trimesters, exposure has been linked to impaired fetal growth and neurodevelopmental effects. Due to the risk of Dravet syndrome seizures, use during pregnancy should be considered only if the benefit to the mother outweighs the potential risk to the fetus. |
| Fetal Monitoring | Monitor seizure frequency and adverse effects in the mother. Obtain serial fetal ultrasounds for growth and anatomy. Consider fetal echocardiography. Assess maternal liver function and complete blood counts regularly due to potential hepatotoxicity and neutropenia. Monitor serum stiripentol concentrations to ensure therapeutic levels. Postpartum, monitor the neonate for withdrawal symptoms, sedation, and feeding difficulties. |
| Fertility Effects | Stiripentol may impair fertility in both males and females based on animal studies. In humans, the effect on fertility is unknown; however, reproductive toxicity has been observed. Women of childbearing potential should be advised to use effective contraception during treatment. Men should consider sperm preservation if fertility is a concern. |
| Clinical Pearls |
| DIACOMIT (stiripentol) is a CYP450 inhibitor; monitor levels of co-administered anticonvulsants. Dose must be adjusted with valproate. Avoid abrupt discontinuation. Use with caution in hematologic disorders; monitor CBC. |
| Patient Advice | Take DIACOMIT exactly as prescribed; do not stop suddenly. · May cause drowsiness or dizziness; avoid driving until you know how it affects you. · Report unusual bruising, bleeding, or signs of infection. · Avoid alcohol. · Do not take with food or milk; take on an empty stomach. |