Precautions and warnings

Use with caution in people with heart problems (like slow heart rate or blocked heart signals), diabetes, liver issues, low blood protein, porphyria, or seizures (especially patients prone to petit mal seizures). Be especially careful with older adults or those who are very weak. When giving this medicine by IV, watch patients closely if they have low blood pressure, heart failure, or have had a heart attack—monitor their blood pressure and heart activity during treatment. Give IV doses slowly, because giving it too fast can cause low blood pressure, drowsiness, abnormal heart rhythms, or heart signal issues. Make sure the medication does not leak outside the vein, and never inject it into an artery. Don’t stop the medication suddenly, as this can cause more seizures, unless it's necessary for safety. This medicine can affect your ability to drive or use machines, so use caution.

Drug Interactions

**Phenytoin can have stronger effects when used with other sedative medicines or alcohol. It can make the harmful effects of paracetamol and lithium worse. If you take acetazolamide, you have a higher risk of developing osteomalacia (soft bones).**

**Phenytoin’s effect may be reduced if you use acyclovir, cancer medicines, benzodiazepines, ciprofloxacin, certain enzyme inducers like carbamazepine and rifampin, folic acid, or vigabatrin.**

**Its blood levels may increase if you’re also using allopurinol, capecitabine, cimetidine, certain enzyme blockers (like fluconazole or delavirdine), disulfiram, methylphenidate, metronidazole, omeprazole, SSRIs, trazodone, or trimethoprim.**

**Phenytoin speeds up the breakdown of many drugs, such as antiarrhythmics, anticonvulsants, antipsychotics, beta-blockers, calcium channel blockers, chloramphenicol, steroids, doxycycline, estrogen, cholesterol-lowering drugs, methadone, theophylline, and tricyclic antidepressants.**

**It can lower the levels or effects of other medicines, including clozapine, ciclosporin, tacrolimus, and certain other drugs processed by liver enzymes, as well as digoxin, itraconazole, levodopa, muscle relaxants, thyroid medicine, and topiramate.**

**Phenytoin can increase the effects of dopamine and ticlopidine. Valproic acid can push phenytoin off its protein binding sites and change phenytoin’s blood levels. When taken with warfarin, phenytoin first increases, then lowers the blood-thinning effect.**

**Potentially Fatal: Phenytoin can make the blood pressure dropping effect of dopamine and the heart-slowing effect of lidocaine much stronger, which can be life-threatening.**

Mode of actions

Phenytoin helps prevent seizures by controlling the movement of sodium ions in and out of nerve cells in the brain’s motor cortex. This keeps the nerve cells stable and reduces seizure activity. As an antiarrhythmic, phenytoin works by lengthening the time before the heart can be excited again and by reducing abnormal heartbeats, which helps control irregular heart rhythms.

Dosage & Administration

Adult: PO Epilepsy Initial: 3-4 mg/kg/day as single dose or in divided doses. Maintenance: 200-500 mg/day.

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.

Pregnancy & Lactation

This medicine is not allowed during pregnancy. Do not use it if you are pregnant. It can be absorbed through the skin and lungs caused can damage your unborn child’s organs and cause congenital disabilities. Strict effective birth control during treatment and for six months after stopping this medicine. If you do become pregnant, stop taking this medicine and discuss your doctor right away.

There is no specific information on whether this medicine passes into breast milk or not. Considering the possible risks for the children, breastfeeding while using this medicine is not recommended and at least two weeks after the last dose. Consult your doctor before breastfeeding.

Pack Size & Price