Phenytoin/Phenobarbital

pharmacological class
Hydantion/Barbiturates
Indication
Epilepsy, tonic-clonic seizure pattern, status epilepticus,seizures,seizures in neurosurgery.
Pregnancy Category
Phenytoin C, Phenobarbital D
Pregnancy
hydantion & barbiturates anticonvulsants cross the placenta risk-benefit must be considered.
Breast-feeding
hydantion & barbiturates anticonvulsants are distributed into breast milk.
Precaution
Cross-sensitivity, patients sensitive to one of the hydantion and barbiturates anticonvulsants may be sensitive to others also.
Pediatrics
Children are more sensitive to side and adverse effects of phenytoin & Phenobarbital.
Geriatrics
Geriatric patients may needs to reduced usual dose.
Contraindication & Drug interaction
Except under special circumstances, this medication should not be used when the following medical problem exists:
Cardiac function impairment, such as Adams-Stokes syndrome, second- and third-degree AV block, sino-atrial block, and sinus bradycardia, Porphyria, acute intermittent or variegata, or history .
Risk-benefit should be considered when the following medical problems exist:
Alcoholism active, Blood dyscrasias, Cardiovascular disease, Diabetes mellitus, Hepatic function impairment, Porphyria, Renal function impairment, Thyroid function impairment
Anemia, severe, Asthma, history of, Diabetes mellitus, especially with Phenobarbital, Drug abuse or dependence, history of, Hepatic coma, premonitory signs of, or, Hepatic function impairment
Hyperkinesis Hyperthyroidism Hypoadrenalism, borderline, Mental depression and/or,
Suicidal tendencies, Pain, acute or chronic, Renal function impairment, especially with intermediate- and long-acting barbiturates,Respiratory disease involving dyspnea or obstruction, particularly status asthmaticus,Sensitivity to barbiturate prescribed, Caution should be used also in debilitated patients because they may react to usual doses with marked excitement, mental depression, and confusion.
Drug interactions
Alcohol, CNS depression-producing medications, Amiodarone, Antacids, Anticoagulants, Chloramphenicol, Cimetidine, Isoniazid, Phenylbutazone, Sulfonamides, Anticonvulsants succinimide, Corticosteroids glucocorticoid, Cyclosporine, Digitalis glycosides, Disopyramide, Doxycycline, Furosemide, Levodopa, Mexiletine, Quinidine, Antidepressants tricyclic, Bupropion, Clozapine, Haloperidol, Loxapine, Maprotiline, Molindone, Monoamine oxidase (MAO) inhibitors, including furazolidone, procarbazine, and selegiline or Phenothiazines, Pimozide, Thioxanthenes, Antidiabetic agents oral, Insulin, Antifungals, azole, including: Fluconazole ,Itraconazole , Ketoconazole ,Miconazole, Antineoplastic agents such as: Bleomycin , Carmustine (BCNU),Cisplatin,Dacarbazine ,Doxorubicin ,Ifosfamide , Methotrexate ,Vinblastine ,Barbiturates, Primidone, Calcium, Calcium channel blocking agents including:Diltiazam ,Nifedipine ,Verapamil, Carbamazepine, Carbonic anhydrase inhibitors, Chlordiazepoxide, Clonazepam, Diazepam, Contraceptives, estrogen-containing oral, Contraceptives progestin-containing , Diazoxide, Dopamine, Estrogens, Progestins, Felbamate, Fluoxetine, Leucovorin, Halothane (and possibly enflurane or methoxyflurane), Lamotrigine, Levothyroxine, Lidocaine, Methadone, Omeprazole, Paroxetine, Phenacemide, Praziquantel, Rifampin, Streptozocin, Sucralfate, Ticlopidine, Valproic acid, Vitamin D, Xanthines, such as:
Aminophylline, Caffeine ,Oxtriphylline, Theophylline
Combinations containing any of the following medications, depending on the amount present, may also interact with this medication.
Acetaminophen, Addictive medications, other, especially CNS depressants with habituating potential, Adrenocorticoids, glucocorticoid and mineralocorticoid ,Chloramphenicol , Corticotropin,Dacarbazine, Metronidazole, Amphetamines, Anesthetics, Anticoagulants, coumarin- or indandione-derivative, Anticonvulsants, succinimide, Antidepressants, tricyclic , Carbonic anhydrase inhibitors, Cyclophosphamide, Disopyramide, Divalproex sodium, Valproic acid, Doxycycline, Fenoprofen, Griseofulvin, Guanadrel, Guanethidine, Haloperidol, Hypothermia-producing medications, Ketamine, Leucovorin, Levothyroxine, Loxapine, Phenothiazines, Thioxanthenes, Maprotiline, Methylphenidate, Mexiletine, , pargyline, Phenylbutazone, Posterior pituitary, Primidone.
Usual Adult Dose
Anticonvulsants
Phenytoin- 100mg three times a day
Phenobarbital- 60 to 250 mg per day as a single dose in divided doses.
Usual Pediatric Dose
Anticonvulsants:
Phenytoin-
Initial: Oral, 5 mg per kg of body weight a day, divided into two or three doses, the dosage being adjusted as needed and tolerated.
Maintenance: Oral, 4 to 8 mg per kg of body weight or 250 mg per square meter of body surface area a day, divided into two or three doses.
Phenobarbital-
Oral ,1 to 6 mg (base)per kg of body weight pr day ,as a single dose or in divided doses.
Side Effects
Those indicating need for medical attention:
Incidence rare
Blood dyscrasias, including agranulocytosis, leucopenia, pancytopenia, and thrombocytopenia, cholestatic jaundice or hepatitis, choreoathetoid movements, transient, cognitive impairment, periarteritis nodosa, Peyronie's disease, pulmonary infiltrates or fibrosis, vitamin D and/or calcium imbalance, Agranulocytosis, allergic reaction, exfoliative dermatitis, hallucinations; hypotension or megaloblastic anemia, Stevens-Johnson syndrome, hrombocytopenia, thrombophlebitis, Hepatic damage, osteopenia or rickets, Sensitivity to barbiturates, mental depression, paradoxical reaction
Those indicating need for medical attention only if they continue or are bothersome
Incidence more frequent
Constipation, mild dizziness, mild drowsiness, nausea and vomiting, Clumsiness or unsteadiness; dizziness or lightheadedness; drowsiness; "hangover" effect
Incidence less frequent
Diarrhea, enlargement of facial features, including thickening of lips, widening of nasal tip, and protrusion of jaw; gynecomastia, headache, hypertrichosis, insomnia, muscle twitching, Exfoliative dermatitis, Stevens-Johnson syndrome, Severe respiratory depression, apnea, laryngospasm, bronchospasm, Prolonged barbiturate therapy may result in osteopenia or rickets, Barbiturate dependence may occur, Anxiety or nervousness; constipation; feeling faint; headache; irritability; nausea or vomiting; nightmares or trouble in sleeping
Those indicating possible barbiturate withdrawal and need for medical attention if they occur after medication is discontinued:
Anxiety or restlessness; muscle twitching; trembling of hands; weakness; dizziness; vision problems; nausea; vomiting; trouble in sleeping, increased dreaming, or nightmares; orthostatic hypotension, Convulsions; hallucinations.
Storage
Store below 30°C (86°F). Protect from light and keep the medicine in the box.
Packaging
Box of 100, Scored tablets Phenytoin/Phenobarbital 100/50mg.