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The PDR link:
http://www.pdrhealth.com/drug_info/index.html
Dilantin
Pronounced: dye-LAN-tin
Generic name: Phenytoin sodium |
Why is this drug prescribed?
Dilantin is an antiepileptic drug, prescribed to control grand
mal seizures (a type of seizure in which the individual experiences a sudden loss of
consciousness immediately followed by generalized convulsions) and temporal lobe seizures
(a type of seizure caused by disease in the cortex of the temporal [side] lobe of the
brain affecting smell, taste, sight, hearing, memory, and movement).
Phenytoin (Dilantin®) was first used in the late 1930s. It has become one of
the more commonly used agents and often is considered the first-line drug to treat
seizures. It is thought to work by suppressing electrical activity in brain nerve cells.
It can be given orally or intravenously (IV), and a newer form of the drug, fosphenytoin
(Cerebryx®) can be injected into muscle. The oral form has the benefit of once-a-day
dosing.
Phenytoin is a first-line agent for treating partial and generalized tonic-clonic
(grand mal) seizures. It is also one of the main agents used with patients who present
with status epilepticus. Phenytoin drug levels need to be monitored with laboratory
testing. The therapeutic concentration recommended is between 10-20mg/L. In addition,
liver function testing and a complete blood count (CBC) need to be followed. Phenytoin has
many interactions with other medications, and its own level can fluctuate when other drugs
are taken.
Some of the side effects associated with its use include gingival hyperplasia
(overgrowth of the gums), hirsuitism/hypertrichosis (excessive hair growth), imbalance,
lethargy, anemia, and, in long-term use, peripheral neuropathy (weakness).
Dilantin may also be used to prevent and treat seizures occurring during and
after neurosurgery (surgery of the brain and spinal cord).
Most important fact about this drug
If you have been taking Dilantin regularly, do not stop abruptly. This
may precipitate prolonged or repeated epileptic seizures without any recovery of
consciousness between attacks--a condition called status epilepticus that can be fatal if
not treated promptly.
How should you take this medication?
It is important that
you strictly follow the prescribed dosage regimen and tell your doctor about any condition
that makes it impossible for you to take Dilantin as prescribed.
If you are given Dilantin Oral Suspension, shake it well before using. Use the
specially marked measuring spoon, a plastic syringe, or a small measuring cup to measure
each dose accurately.
Swallow Dilantin Kapseals whole. Dilantin Infatabs can be either chewed thoroughly and
then swallowed, or swallowed whole. The Infatabs are not to be used for once-a-day dosing.
Do not change from one form of Dilantin to another without consulting your doctor.
Different products may not work the same way.
Depending on the type of seizure disorder, your doctor may give you another drug with
Dilantin.
--If you miss a dose...
If you take one dose a day, take the dose you missed as soon as you remember. If you do
not remember until the next day, skip the missed dose and go back to your regular
schedule. Do not take 2 doses at once.
If you take more than 1 dose a day, take the missed dose as soon as possible. If it is
within 4 hours of your next dose, skip the one you missed and go back to your regular
schedule. Do not take 2 doses at once.
If you forget to take your medication 2 or more days in a row, check with your doctor.
--Storage instructions...
Store at room temperature away from light and moisture.
What side effects may occur?
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Side effects cannot be anticipated. If any develop or change in intensity, inform your
doctor as soon as possible. Only your doctor can determine whether it is safe for you to
continue taking Dilantin.
- More common side effects may include:
Decreased coordination, involuntary eye movement, mental confusion, slurred speech
- Other side effects may include:
Abnormal hair growth, abnormal muscle tone, blood disorders, coarsening of facial
features, constipation, dizziness, enlargement of lips, fever, headache, inability to fall
asleep or stay asleep, joint pain, nausea, nervousness, overgrowth of gum tissue,
Peyronie's disease (a disorder of the penis that causes the penis to bend on an angle
during erection, often making intercourse painful or difficult), rapid and spastic
involuntary movement, skin peeling or scaling, skin rash, tremors, twitching, vomiting,
yellowing of skin and eyes
Why should this drug not be prescribed?
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If you have ever had an allergic reaction to or are sensitive to phenytoin or similar
epilepsy medications such as Peganone or Mesantoin, do not take Dilantin. Make sure your
doctor is aware of any drug reactions you have experienced.
Special warnings about this medication
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Tell your doctor if you develop a skin rash. If the rash is scale-like, characterized
by reddish or purplish spots, or consists of (fluid-filled) blisters, your doctor may stop
Dilantin and prescribe an alternative treatment. If the rash is more like measles, your
doctor may have you stop taking Dilantin until the rash is completely gone.
Because Dilantin is processed by the liver, people with impaired liver function, older
adults, and those who are seriously ill may show early signs of drug poisoning.
Practicing good dental hygiene minimizes the development of gingival hyperplasia
(excessive formation of the gums over the teeth) and its complications.
Avoid drinking alcoholic beverages while taking Dilantin.
Possible food and drug interactions when taking this medication
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If Dilantin is taken with certain other drugs, the effects of either could be
increased, decreased, or altered. It is especially important to check with your doctor
before combining Dilantin with the following:
Alcohol
Amiodarone (Cordarone)
Antacids containing calcium
Blood-thinning drugs such as Coumadin
Chloramphenicol (Chloromycetin)
Chlordiazepoxide (Librium)
Diazepam (Valium)
Dicumarol
Digitoxin (Crystodigin)
Disulfiram (Antabuse)
Doxycycline (Vibramycin)
Estrogens such as Premarin
Felbamate (Felbatol)
Fluoxetine (Prozac)
Furosemide (Lasix)
Isoniazid (Nydrazid)
Major tranquilizers such as Mellaril and Thorazine
Methylphenidate (Ritalin)
Molindone hydrochloride (Moban)
Oral contraceptives
Phenobarbital
Quinidine (Quinidex)
Reserpine (Diupres)
Rifampin (Rifadin)
Salicylates such as aspirin
Seizure medications such as Depakene, Depakote, Tegretol, and Zarontin
Steroid drugs such as prednisone (Deltasone)
Sucralfate (Carafate)
Sulfa drugs such as Gantrisin
Theophylline (Theo-Dur, others)
Tolbutamide (Orinase)
Trazodone (Desyrel)
Ulcer medications such as Tagamet and Zantac
Tricyclic antidepressants (such as Elavil, Norpramin, and others) may cause seizures in
susceptible people, making a dosage adjustment of Dilantin necessary.
Hyperglycemia (high blood sugar) may occur in people taking Dilantin, which blocks the
release of insulin. People with diabetes may experience increased blood sugar levels due
to Dilantin.
Abnormal softening of the bones may occur in people taking Dilantin because of
Dilantin's interference with vitamin D metabolism.
Special information if you are pregnant or breastfeeding
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If you are pregnant or plan to become pregnant, inform your doctor immediately. Because
of the possibility of birth defects with antiepileptic drugs such as Dilantin, you may
need to discontinue the drug. Do not, however, stop taking it without first consulting
your doctor. Dilantin appears in breast milk; breastfeeding is not recommended during
treatment with this drug.
Recommended dosage
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Dosage is tailored to each individual's needs. Your doctor will monitor blood levels of
the drug closely, particularly when switching you from one drug to another.
ADULTS
Standard Daily Dosage
If you have not had any previous treatment, your doctor will have you take one
100-milligram Dilantin capsule 3 times daily to start.
On a continuing basis, most adults need 1 capsule 3 to 4 times a day. Your doctor may
increase that dosage to 2 capsules 3 times a day, if necessary.
Once-A-Day Dosage
If your seizures are controlled on 100-milligram Dilantin capsules 3 times daily, your
doctor may allow you to take the entire 300 milligrams as a single dose once daily.
CHILDREN
The starting dose is 5 milligrams per 2.2 pounds of body weight per day, divided into 2
or 3 equal doses; the most a child should take is 300 milligrams a day. The regular daily
dosage is usually 4 to 8 milligrams per 2.2 pounds. Children over 6 years of age and
adolescents may need the minimum adult dose (300 milligrams per day).
Overdosage
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An overdose of Dilantin can be fatal. If you suspect an overdose, seek medical
attention immediately.
- Symptoms of Dilantin overdose may include:
Coma, difficulty in pronouncing words correctly, involuntary eye movement, lack of muscle
coordination, low blood pressure, nausea, sluggishness, slurred speech, tremors, vomiting
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