Dosage ; 150-300mg daily in single or divided doses (max.600mg).
Children: 5-8mg/kg daily in 1 or 2 doses to be taken after meals.
Status epilepticus, acute symptomatic seizures associated with trauma or neurosurgery.
By slow intravenous injection or infusion
(with blood-pressure and ECG monitoring), neonate, initially 20 mg/kg as a loading dose then 2.5-5 mg/kg twice daily.
Child 1 mont-12 years initially 20 mg/kg as a loading dose then 2.5-5 mg/kg twice daily,
Child 12-18 years initially 20 mg/kg as a loading dose then up to 100 mg 3-4 times daily.
| Brand Name | Manufacturer Name | Distributor | Drug Strength | Packaging | Formulation | Formulation Strength | Price |
|---|---|---|---|---|---|---|---|
| Epanutin | Pfizer Global Pharmaceuticals | Phillips Pharmaceuticals Ltd. | 50mg | 28 | Capsule | per capsule | KES 375.00 |
| Epanutin | Pfizer Global Pharmaceuticals | Phillips Pharmaceuticals Ltd. | 100mg | 84 | Capsule | per capsule | KES 859.00 |
| Epanutin | Pfizer Global Pharmaceuticals | Phillips Pharmaceuticals Ltd. | 50mg | 5 | Injection | per vial | KES 1,877.00 |
| Epanutin | Pfizer Global Pharmaceuticals | Phillips Pharmaceuticals Ltd. | 50mg | 10 | Injection | per vial | KES 2,632.81 |
| Phenytoin | Laboratory & Allied Ltd. | Laboratory & Allied Ltd | 50mg | 1000 | Capsule | per capsule | KES 480.00 |
| Phenytoin | Laboratory & Allied Ltd. | Laboratory & Allied Ltd | 100mg | 1000 | Capsule | per capsule | KES 1,000.00 |
| Epigon | Prism Life Sciences | Galaxy Pharmaceuticals Ltd | 100mg | 100 | Tablet | per tablet | KES 150.00 |
| Phenytoin | Biodeal Laboratories Ltd. | Biodeal Laboratories Ltd. | 100mg | 1000 | Tablet | per tablet | KES 1,000.00 |
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Phenytoin More info |
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| Mode Of Action | The mechanism of action of phenytoin is not fully known. It is thought to involve stabilization of neuronal membranes at the cell body, axon, and synapse and limitation of the spread of neuronal or seizure activity. It decreases sodium and calcium ion influx by prolonging voltage-dependent channel inactivation time during generation of nerve impulses. |
| Drug Indication | Grand mal and temporal epilepsy; migraine; arrhythmia; skeletal muscle relaxant; trigeminal neuralgia. |
| Precautions | It has a low therapeutic index hence it requires therapeutic drug monitoring; severe myocardial insufficiency; to be withdrawn or substituted gradually; administration of vitamin K to mothers during delivery and infant after delivery. |
| Contra-Indications | |
| Side Effects | Hirsutism; gingival hyperplasia; acne; course facies and rashes; ataxia; GI disturbances; slurred speech; nystagmus; blurred vision; diplopia; headache; drowsiness; skin eruptions; blood dyscrasia; tinnitus; hyperglycaemia; weight gain; gynaecomastia. |
| Dosage | 150-300mg daily in single or divided doses (max.600mg). Children: 5-8mg/kg daily in 1 or 2 doses to be taken after meals. Status epilepticus, acute symptomatic seizures associated with trauma or neurosurgery. By slow intravenous injection or infusion (with blood-pressure and ECG monitoring), neonate, initially 20 mg/kg as a loading dose then 2.5-5 mg/kg twice daily. Child 1 mont-12 years initially 20 mg/kg as a loading dose then 2.5-5 mg/kg twice daily, Child 12-18 years initially 20 mg/kg as a loading dose then up to 100 mg 3-4 times daily. |
| Pregnancy Category | Category D |
| Pregnancy Category Description | Drugs, which have caused, are suspected to have caused, or may be expected to cause an increased rise in the frequency of malformations or irreversible damage. These drugs may also have adverse pharmacological effects required required |
| Drug Category | DRUGS ACTING ON CNS |
| Drug Sub-Category | Anticonvulsants
Specific dosages; Status epilepticus: I.V.: Loading dose: Manufacturer recommends 10-15 mg/kg, however, 15-20 mg/kg is generally recommended; maximum rate: 50 mg/minute Anticonvulsant: Oral: Loading dose: 15-20 mg/kg; based on phenytoin serum concentrations and recent dosing history; administer oral loading dose in 3 divided doses given every 2-4 hours to decrease GI adverse effects and to ensure complete oral absorption; maintenance dose: 300 mg/day or 5-6 mg/kg/day in 3 divided doses or 1-2 divided doses using extended release (range: 200-1200 mg/day) Dosage adjustment in obesity: Loading dose: Use adjusted body weight (ABW) correction based on a pharmacokinetic study of phenytoin loading doses in obese patients (Abernethy, 1985). The larger correction factor (ie, 1.33) is due to a doubling of Vd estimated in these obese patients. ABW = [(Actual body weight – IBW) x 1.33] + IBW Maximum loading dose: 2000 mg (Erstad, 2004) Maintenance doses should be based on ideal body weight, conventional daily doses with adjustments based upon therapeutic drug monitoring and clinical effectiveness. (Abernethy, 1985; Erstad, 2002; Erstad, 2004) Dosing: Pediatric (For additional information see "Phenytoin: Pediatric drug information") Note: Phenytoin base (eg, oral suspension, chewable tablets) contains ~8% more drug than phenytoin sodium (~92 mg base is equivalent to 100 mg phenytoin sodium). Dosage adjustments and closer serum monitoring may be necessary when switching dosage forms. Status epilepticus: I.V.: Infants and Children: Loading dose: 15-20 mg/kg in a single or divided dose; maintenance dose: Initial: 5 mg/kg/day in 2 divided doses, usual doses: 6 months to 3 years: 8-10 mg/kg/day 4-6 years: 7.5-9 mg/kg/day 7-9 years: 7-8 mg/kg/day 10-16 years: 6-7 mg/kg/day, some patients may require every 8 hours dosing Anticonvulsant: Children: Oral: Refer to adult dosing. Dosing: Geriatric Refer to adult dosing. Dosing: Renal Impairment Phenytoin level in serum may be difficult to interpret in renal failure. Monitoring of free (unbound) concentrations or adjustment to allow interpretation is recommended. Dosing: Hepatic Impairment Safe in usual doses in mild liver disease; clearance may be substantially reduced in cirrhosis and plasma level monitoring with dose adjustment advisable. Free phenytoin levels should be monitored closely |