Article Contents ::
Details About Generic Salt :: Phenytoin
Main Medicine Class:: Nervous System Sub Medicine Class :: Anti Epileptics
| 1C. ANTI-EPILEPTICS in 1. NERVOUS SYSTEM |
| PHENYTOIN |
| HYDANTOIN | ANTI-EPILEPTIC |
| PK: A: Slow D: Neonates/ premature: 1-1.2 L/kg, full-term: 0.8-0.9 L/kg, infants: 0.7-0.8 L/kg, child: 0.7 L/kg, adult: 0.6-0.7 L/kg (Vd) E: Urine |
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Indications & Dose: NEUROSURGERY Prophylactic therapy IV Adult 100-200mg at 4h intervals during surgery & immediately in postoperative period | STATUS EPILEPTICUS Emergency therapy IV Adult Loading dose 15-20mg/kg, max 50mg/min Child Neonate: Loading dose: 20mg/kg then 2.5-5mg/kg BID, 1 month-12 yr: Loading dose: 20mg/kg then 2.5-5mg/kg BID, 12-18 yr: Loading dose: 20mg/kg then 100mg TID/QID | TONIC-CLONIC STATUS EPILEPTICUS IV Adult Inj/inf: 10-15mg/kg at 50mg/min, MD 100mg q6-8h (PO/IV) | VENTRICULAR ARRHYTHMIAS IV Adult 3.5–5mg/kg rate not exceeding 50mg/min, repeated once if needed |
| Contra: Hypersensitivity, porphyria, avoid parenteral use in sinus bradycardia, sino-atrial block, second & third degree heart block, stokes-adams syndrome
Precautions: Avoid abrupt withdrawal, hepatic/renal impairment, hypotension, HF ADR: Serious: Hypersensitivity reactions, SJS, TEN, osteomalacia, hepatotoxicity, CNS depression, thrombocytopenia, arrhythmias, CV collapse, hypotension, respiratory collapse, blurred vision, hepatitis, neurological changes, Others: leukopenia, cerebellar vestibular symptom, ataxia, nystagmus, diplopia, slurred speech, behavioural disorders, hallucinations, hyperglycemia, gingival hyperplasia, acne, coarse facies, hirsutism, fever, Headache, sedation, confusion DDI: Serious Pyridoxine (at high doses) decreases drug level, Chloramphenicol (when given by IV)increases drug level and leads to toxicity, Acenocoumarol causes severe bleeding, Carboplatin/Bleomycin/Ciprofloxacin/Cisplatin/Cyclophosphamide/Diazoxide/Doxorubicin/Etoposide/Folic acid/Mercaptopurine/Methotrexate/Rifampicin/Tamoxifen/Vinblastine/Vincristine decreases drug level, Warfarin efficacy is increased, Cimetidine/Amiodarone/Cotrimoxazole/Felbamate/Fluconazole/Fluoxetine/Fluvoxamine/Imipramine/Isoniazid/Miconazole/Nifedipine/Sulfadiazine/Ticlopidine/Trimethoprim/Voriconazole increases drug level, Disulfiram increases drug level and causes toxicity, Pregabalin level is reduced, Ketoconazole/Itraconazole levels are decreased, Sertraline/Paroxetine levels are reduced, Prochlorperazine/Chlorpromazine may alter the drug level, Thioridazine metabolites are reduced, Metronidazole prolongs half-life of the drug (when given by IV), Nitrofurantoin/Clofazimine reduces drug level Others Allopurinol increases drug level, Nimodipine/Felodipine/Verapamil levels are decreased, Carbamazepine may increase/decrease the drug level Diet: With food Monitor: BP, drug level, CBC, LFTs |
