Phenytoin drug data and news

---

New Study Shows Initial Treatment With 800 mg/day Imatinib ...  May 15, 2006
...least 50% and clinical response should be carefully monitored in patients receiving Gleevec tablets with a potent CYP3A4 inducer such as rifampin or phenytoin. ... - DG News

Anticonvulsant Treatment for Psychiatric and Seizure Indications ...  May 4, 2006
...of a psychiatric disorder only (1). A majority of those with a seizure disorder (66 percent) were given a prescription for phenobarbital or phenytoin, and most ... - Psychiatric Services (subscription)

Lamotrigine Improves Depressed Mood in Women With Epilepsy ...  May 11, 2006
Background antiepileptic drugs were phenytoin (26%), carbamazepine (19%), valproic acid (15%), oxcarbazepine (13%) and topiramate (9%). ... - DG News

Self-Mutilation of Fingers After Cervical Spinal Cord Injury  May 9, 2006
...cases. Carbamazepine was used in four of the cases. Phenytoin and gabapentin were each utilized in two separate cases. Soft barriers ... - Psychosomatics (subscription)

Neuropathic Pain: An Update on Effective Management Strategies  May 5, 2006
Other antiepileptic agents include the first-generation agents (eg, phenytoin and carbamazepine) and second-generation agents (eg, lamotrigine, levetiracetam ... - Medscape (subscription)

Halozyme Therapeutics Reports First Quarter 2006 Financial Results  May 10, 2006
Precautions for the use of Hylenex consist of incompatibility with furosemide, benzodiazepines and phenytoin, and recommendation for consulting appropriate ... - PR Newswire (press release),

Insulin-dependent Diabetes Mellitus  Apr 30, 2006
...cause diabetes. Certain drugs can also cause temporary diabetes, including corticosteroids, beta-blockers, and phenytoin. Rare genetic ... - About - News & Issues,

Can you diagnose cancer without a biopsy?  Apr 30, 2006
Some drugs – anticonvulsants including phenytoin and sodium valproate, benzodiazepines like diazepam (valium) and high-dose steroids – increase the risk of ... - The Herald,

There are many drugs which may increase or decrease phenytoin levels or which phenytoin may affect. Serum level determinations for phenytoin are especially helpful when possible drug interactions are suspected. The most commonly occurring drug interactions are listed below:

1. Drugs which may increase phenytoin serum levels include: acute alcohol intake, amiodarone, chloramphenicol, chlordiazepoxide, diazepam, dicumarol, disulfiram, estrogens, H₂-antagonists, halothane, isoniazid, methylphenidate, phenothiazines, phenylbutazone, salicylates, succinimides, sulfonamides, tolbutamide, trazodone.

2. Drugs which may decrease phenytoin serum levels include: carbamazepine, chronic alcohol abuse, reserpine, and sucralfate. Moban brand of Molindone Hydrochloride contains calcium ions which interfere with the absorption of phenytoin. Ingestion times of phenytoin and antacid preparations containing calcium should be staggered in patients with low serum phenytoin levels to prevent absorption problems.

3. Drugs which may either increase or decrease phenytoin serum levels include: phenobarbital, sodium valproate, and valproic acid. Similarly, the effect of phenytoin on phenobarbital, valproic acid and sodium valproate serum levels is unpredictable.

4. Although not a true drug interaction, tricyclic antidepressants may precipitate seizures in susceptible patients and phenytoin dosage may need to be adjusted.

5. Drugs whose efficacy is impaired by phenytoin include: corticosteroids, coumarin anticoagulants, digitoxin, doxycycline, estrogens, furosemide, oral contraceptives, quinidine, rifampin, theophylline, vitamin D.

Drug/Laboratory Test Interactions

Phenytoin may cause decreased serum levels of protein-bound iodine (PBI). It may also produce lower than normal values for dexamethasone or metyrapone tests. Phenytoin may cause increased serum levels of glucose, alkaline phosphatase, and gamma glutamyl transpeptidase (GGT).