Mesantoin (Mephenytoin) - Drug Interactions, Contraindications, Overdosage, etc

DRUG INTERACTIONS

Drug Interactions

There have been no reports of drug interactions associated with the use of Mesantoin^® (mephenytoin), however, caution should be used when Mesantoin^® (mephenytoin) is coadministered with products known to interact with phenytoin.

OVERDOSAGE

Lethal Dose

While the fatal dose of Mesantoin^® (mephenytoin) has not been established, the minimum lethal dose for adults is probably in the region of 3 to 5 gm.

Symptoms and signs of overdosage include: ataxia, dysarthria, nystagmus, drowsiness, confusion and coma with areflexia.

Hypotension, which may proceed to a shock-like state, can also occur.

Tachycardia and arrhythmias of ventricular origin have also been reported.

Terminal hyperpyrexia was reported in one fatal case.

Transient thrombocytopenia, hemorrhagic bullae and petechal rash have been reported following a single overdose.

Treatment

There is no specific antidote for an overdosage of Mesantoin^® (mephenytoin).

General measures include:

• Elimination of offending drug by induction of emesis, gastric lavage, catharsis, or activated charcoal.
• Maintenance of pulmonary ventilation with suction or endotracheal intubation.

Correction of hypotension, using a pressor agent.

• Maintenance of normal body temperature.

EKG Monitoring

The hydantoins as a group are known to have a depressive effect on the heart, particularly in high doses. If arrhythmias occur, regular EKG monitoring should begin at once.

CONTRAINDICATIONS

Mesantoin^® (mephenytoin) is contraindicated in patients who have previously shown hypersensitivity to hydantoin products.

DRUG ABUSE AND DEPENDENCE

Abuse

To date, there have been no reports of abuse with the use of Mesantoin^® (mephenytoin).

Dependence

To date, there have been no reports of dependence (psychological or physical) with the use of Mesantoin^® (mephenytoin).