ফেনাইটোইন সোডিয়াম (Phenytoin) এ আছে Phenytoin (ফেনাইটোইন সোডিয়াম)। ফেনাইটোইন সোডিয়াম (Phenytoin) এর কাজ, খাওয়ার নিয়ম, পার্শ্বপ্রতিক্রিয়া, মাত্রা ও সেবনবিধি, সতর্কতা, মিথষ্ক্রিয়া, গর্ভাবস্থায় ও স্তন্যদানকালে ব্যবহার, মাত্রাধিক্যতাঃ
ফেনাইটোইন স্নায়ু প্রবণতা প্রজন্মের সময় মোটর কর্টেক্সে কোষের ঝিল্লি জুড়ে সোডিয়াম আয়নগুলির প্রবাহ বৃদ্ধি বা হ্রাস দ্বারা অ্যান্টিকনভালসেন্ট হিসাবে কাজ করে; এইভাবে নিউরোনাল ঝিল্লি স্থিতিশীল এবং কমে যাওয়া ক্রিয়াকলাপ। এটি কার্যকর প্রতিরোধক সময়কাল বাড়িয়ে এবং ভেন্ট্রিকুলার পেসমেকার অটোমেটিভিটি দমন করে, হৃদয়ে ক্রিয়াকলাপকে সংক্ষিপ্ত করে একটি অ্যান্টিআরিথাইমিক হিসাবে কাজ করে।
কাজ
পেরেনট্রাল ফেনাইটোইন সাধারণ টনিক-ক্লোনিক স্থিতির মৃগী রোগের চিকিত্সা এবং নিউরোসার্জির সময় ঘটে যাওয়া আক্রান্তদের প্রতিরোধ এবং চিকিত্সার জন্য দেওয়া হয়। ইনফ্রেভেনস ফেনাইটোইনকেও মৌখিক ফিনাইটিনের জন্য স্বল্প-মেয়াদী ব্যবহার হিসাবে প্রতিস্থাপিত করা যেতে পারে। পেরেনট্রাল ফেনাইটোইন কেবল তখনই ব্যবহার করা উচিত যখন মৌখিক ফেনিটাইন প্রশাসন সম্ভব হয় না।
থেরাপিউটিক ক্লাস
Adjunct anti-epileptic drugsমাত্রা ও সেবনবিধি
Oral:Epilepsy:
- Adult: Initially, 3-4 mg/kg daily as single dose or in divided doses. Alternatively, 150-300 mg daily increased gradually to 600 mg daily if necessary. Maintenance: 200-500 mg daily.
- Child: Initially, 5 mg/kg daily in 2-3 divided doses. Maintenance: 4-8 mg/kg daily in divided doses. Max dose: 300 mg daily.
Intravenous:Tonic-clonic status epilepticus:
- Adult: Adjunctive therapy with a benzodiazepine (e.g. diazepam): 10-15 mg/kg by slow inj or intermittent infusion at a max rate of 50 mg/min. Maintenance: 100 mg IV (or orally) given every 6-8 hr.
- Child: Neonates: 20 mg/kg as a loading dose, then 2.5-5 mg/kg bid; 1 mth-12 yr: 18 mg/kg as a loading dose, then 2.5-5 mg/kg bid; >12 yr: 18 mg/kg as a loading dose, then up to 100 mg 3-4 times daily.
Should be taken with food. When administering to patients on nasogastric or other enteral feeds, do not administer feeds 2 hr before or after a dose. Be consistent throughout therapy in relation to feed times. Do not switch dosage forms/brands w/o prior consideration.
পার্শ্ব প্রতিক্রিয়া
Hypersensitivity, lack of appetite, headache, dizziness, tremor, transient nervousness, insomnia, GI disturbances (e.g. nausea, vomiting, constipation), tenderness and hyperplasia of the gums, acne, hirsutism, coarsening of the facial features, rashes, osteomalacia. Phenytoin toxicity as manifested as a syndrome of cerebellar, vestibular, ocular effects, notably nystagmus, diplopia, slurred speech, and ataxia; also with mental confusion, dyskinesias, exacerbations of seizure frequency, hyperglycaemia. Solutions for inj may cause local irritation or phlebitis. Prolonged use may produce subtle effects on mental function and cognition, especially in children.
সতর্কতা
Cardiovascular disease, e.g. sinus bradycardia, heart blocks; DM; hepatic impairment; hypoalbuminemia; porphyria; seizures (may increase frequency of petit mal seizures); debilitated patients; elderly. Caution in IV admin in hypotension, heart failure or MI, monitor BP and ECG during therapy. IV must be given slowly (too rapid admin may cause hypotension, CNS depression, cardiac arrhythmias and impaired heart conduction). Extravasation and intra-arterial admin must be avoided. Do not discontinue abruptly (may increase seizure frequency), unless safety concerns require a more rapid withdrawal. May impair ability to drive or operate machinery.
ঔষধের মিথষ্ক্রিয়া
Effects with other sedative drugs or ethanol may be potentiated. Enhances toxic effects of paracetamol, lithium. Increased risk of osteomalacia with acetazolamide. Decreased serum levels/effects with acyclovir, antineoplastics, benzodiazeines, ciprofloxacin, CYP2C9 inducers (e.g. carbamazepine), CYP2C19 inducers (e.g. rifampin), folic acid, vigabatrin. Increased serum concentrations with allopurinol, capecitabine, cimetidine, CYP2C9 inhibitors (e.g. fluconazole), CYP2C19 inhibitors (e.g. delavirdine), disulfiram, methylphenidate, metronidazole, omeprazole, SSRI, trazodone, trimethoprim. Increases metabolism of antiarrhythmics, anticonvulsants, antipsychotics, beta-blockers, calcium channel blockers, chloramphenicol, corticosteroids, doxycycline, oestrogens, HMG-CoA reductase inhibitors, methadone, theophylline, TCAs. Decreases levels/effects of clozapine, ciclosporin, tacrolimus, CYP2B6 substrates (e.g. bupropion, selegiline), CYP2C8 substrates (e.g. amiodarone), CYP2C9 substrates (e.g. celecoxib), CYP2C19 substrates (e.g. citalopram), CYP3A4 substrates (e.g. benzodiazepines), digoxin, itraconazole, levodopa, neuromuscular-blocking agents, thyroid hormones, topiramate. Increases levels/effect of dopamine, ticlopidine. Valproic acid may displace phenytoin from binding sites; and affect phenytoin serum concentrations. Transiently increases the hypothrombinaemia response to warfarin initially, followed by an inhibition of the response.
গর্ভাবস্থায় ও স্তন্যদানকালে ব্যবহার
বিভাগ ডি: মানুষের ভ্রূণের ঝুঁকি সম্পর্কে ইতিবাচক প্রমাণ রয়েছে তবে গর্ভবতী মহিলাদের ব্যবহার থেকে প্রাপ্ত সুবিধাগুলি ঝুঁকি থাকা সত্ত্বেও গ্রহণযোগ্য হতে পারে।
মাত্রাধিক্যতা
Thelethaldose in pediatric patients is not known. The lethal dose in adults is estimated to be 2 to 5 grams. The initial symptoms arenystagmus,ataxia, anddysarthria. Other signs aretremor, hyperreflexia,lethargy, slurred speech, blurred vision, nausea, and vomiting. The patient may become comatose andhypotensive. Death is caused by respiratory andcirculatorydepression.
There are marked variations among individuals with respect tophenytoinserum levels where toxicity may occur. Nystagmus, onlateralgaze, usually appears at 20 mcg/mL, ataxia at 30 mcg/mL, dysarthria and lethargy appear when the serum concentration is over 40 mcg/mL, but as high a concentration as 50 mcg/mL has been reported without evidence of toxicity. As much as 25 times the therapeutic dose has been taken to result in a serum concentration over 100 mcg/mL with complete recovery. Irreversible cerebellar dysfunction andatrophyhave been reported.
Treatment: Treatment is nonspecific since there is no knownantidote. The adequacy of the respiratory and circulatory systems should be carefully observed and appropriate supportive measures employed.Hemodialysiscan be considered since phenytoin is not completely bound to plasma proteins. Total exchangetransfusionhas been used in the treatment of severe intoxication in pediatric patients. In acute overdosage the possibility of other CNS depressants, including alcohol, should be borne in mind.
প্রতিলক্ষণ
Phenytoin Sodium is contraindicated in patients with:
- A history of hypersensitivity to phenytoin, its inactive ingredients, or other hydantoins
- Sinus bradycardia, sino-atrialblock, second and third degree A-V block, and Adams-Stokes syndrome because of the effect ofparenteralphenytoin onventricularautomaticity.
- A history of prior acute hepatotoxicity attributable to phenytoin
- Coadministration with delavirdine because of the potential for loss of virologic response and possible resistance to delavirdine or to the class of non-nucleosidereverse transcriptaseinhibitors.
বিশেষ সতর্কতা
Pediatric Use: A loading dose of 15 to 20 mg/kg of Phenytoin intravenously will usually produce serum concentrations of phenytoin within the generally accepted serum total concentrations between 10 and 20 mcg/mL (unbound phenytoin concentrations of 1 to 2 mcg/mL). Because of the increased risk of adverse cardiovascular reactions associated with rapid administration Phenytoin should be injected slowly intravenously at a rate not exceeding 1 to 3 mg/kg/min or 50 mg per minute, whichever is slower
Geriatric Use: Phenytoin clearance tends to decrease with increasing age. Lower or less frequent dosing may be required
Renal and Hepatic Impairment Or Hypoalbuminemia: The liver is the site of biotransformation. Patients with impaired liver function, elderly patients, or those who are gravely ill may show early toxicity. Because the fraction of unbound phenytoin is increased in patients with renal or hepatic disease, or in those with hypoalbuminemia, the monitoring of phenytoin serum levels should be based on the unbound fraction in those patients.
সংরক্ষণ
Intravenous: Store at room temperature of 15-30°C.Oral:
- Tablet/capsule: Store below 30°C. Protect from light and moisture;
- Oral suspension: Store at room temperature of 20-25°C, do not freeze, protect from light.