PHENYTOIN SODIUM

Phenytoin Sodium 50mg/1mL, Solution for injection

Caffeine-containing Foods/Beverages

· Severity: Moderate

· Notes for Consumers: Hydantoins may decrease the actions of Caffeine; if you have a high intake of caffeinated foods or beverages you may experience a headache or irritability from decreased caffeine levels while taking these drugs until your body adjusts. If you take Caffeine for other purposes, notify your health care provider if you think Caffeine is not working as well for you.

· Notes for Professionals: Higher caffeine doses may be needed after hydantoin administration; hydantoins increase caffeine elimination.

Phenytoin Sodium 50mg/1mL, Solution for injection

Marijuana

· Severity: Moderate

· Notes for Consumers: The effects of marijuana may be increased and side effects may get worse if it is combined with this medicine. Do not drive or operate machinery until you know how this combination will affect you. Contact your health care provider right away if you notice slurred speech, confusion, severe drowsiness, increased heart rate, or any other new or unusual side effects.

· Notes for Professionals: The incidence of marijuana associated adverse effects may change following coadministration with phenytoin or fosphenytoin. Phenytoin is an inhibitor of CYP2C9 and an inducer of CYP3A4, two isoenzymes responsible for the metabolism of marijuana's most psychoactive compound, delta-9-tetrahydrocannabinol (Delta-9-THC). When given concurrently with phenytoin, the amount of Delta-9-THC converted to the active metabolite 11-hydroxy-delta-9-tetrahydrocannabinol (11-OH-THC) may be altered. These changes in Delta-9-THC and 11-OH-THC plasma concentrations may result in an altered marijuana adverse event profile.

Phenytoin Sodium 50mg/1mL, Solution for injection

Enteral Feedings

· Severity: Major

· Notes for Consumers: Enteral feedings may decrease the effectiveness of Phenytoin suspension, by decreasing its absorption from the stomach. Take Phenytoin suspension 1 to 2 hours before or 1 to 2 hours after you take enteral feedings to limit an interaction. Phenytoin capsules do not appear to be affected by this interaction. If you are being treated for a seizure disorder, contact your health care provider if you notice an increase in the number or severity of seizures.

· Notes for Professionals: The oral absorption of phenytoin suspension can be substantially reduced (up to 70%) by the concurrent administration of enteral feedings. Conversely, when enteral feedings are halted, phenytoin concentrations may markedly rise. Other oral dosage forms of phenytoin (e.g., phenytoin sodium) do not interact with enteral feedings to the same extent as the oral suspension. There are several ways to manage patients receiving enteral feedings and phenytoin. If the patient is on intermittent feedings, time phenytoin administration 1 to 2 hours after the feeding, flush the tubing with water or normal saline, and delay subsequent feedings for another 1 to 2 hours. If practical, continuous feedings may be held for 1 to 2 hours before and after each phenytoin dose (again, flushing the tubing after drug administration); to minimize the amount of time feedings are held, give phenytoin suspension twice daily rather than more often. If enteral feeding cannot be held, increase the dose of phenytoin suspension to account for the interaction or consider the use of parenteral phenytoin/fosphenytoin. If larger enteral doses are used, phenytoin dosage reduction may be required when enteral nutrition is stopped, and an oral diet resumed. Regardless of the approach, monitor serum phenytoin concentrations and clinical status, adjusting the dosage to achieve desired therapeutic outcomes.

Phenytoin Sodium 50mg/1mL, Solution for injection

Alcohol

· Severity: Major

· Notes for Consumers: You should avoid alcoholic beverages while taking Phenytoin. Alcohol can affect seizure control and interfere with the drug treatment, and may increase the risk of serious side effects. Decreased alertness, drowsiness, falls, or other side effects may occur. Do not drive or operate machinery if you are drinking alcohol-containing beverages. If you notice slurred speech, confusion, severe weakness, or difficulty breathing, contact your health care provider immediately.

· Notes for Professionals: Phenytoin theoretically can add to the CNS-depressant effects of ethanol. Chronic ingestion of ethanol induces hepatic microsomal isozymes and increases the clearance of phenytoin. Ethanol also exhibits epileptogenic potential. Ethanol should generally be avoided in patients on fosphenytoin or phenytoin. Acute ingestion of small amounts of ethanol in non-alcoholic patients does not appear to affect the hepatic metabolism of phenytoin to a clinically significant degree.

<b>DISCLAIMER:</b><em> This drug information content is provided for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Patients should always consult their physician with any questions regarding a medical condition and to obtain medical advice and treatment. Drug information is sourced from GSDD (Gold Standard Drug Database ) provided by Elsevier.</em>