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- Medications
and Epilepsy
Epilepsy can be a very difficult condition to accept, but modern
anticonvulsant drug therapy has dramatically improved prospects
for people with epilepsy.
None of the existing drugs can cure epilepsy, but carefully-prescribed
and well-followed regimens of medication have become increasingly
successful in preventing seizures.
Whenever possible, physicians employ monotherapy, the use of a
single drug, to control seizures. Some people, however, are subject
to more than one kind of epileptic seizure, and may be obliged
to take more than one medication to gain control over the condition.
Although the obligation to follow a stict course of anticonvulsant
therapy can be frustrating, the right medication can greatly improve
a person's ability to lead a full, active life.
Fluctuations in condition: many people with epilepsy are
able to identify circumstances and things that are likely to trigger
a seizure. Some of these triggers are shared by a large number
of people with epilepsy, while others are highly specific to certain
individuals.
Determining the correct dosage and best medication for any one
person's needs can be a very difficult part of drug therapy. It
may take a long time to arrive at the best initial routine, and
drug requirements may change over the years.
The source of the problem is that seizures may vary in their occurrence.
It is often difficult to identify the precise source of these
changes in seizure patterns or the causes of changing susceptibility
to factors that elicit seizures. Therefore particular important
to follow your medication schedule.
Finding the right drug: reaction to given drugs varies
from one person to the next. Medication that works for one peeson
with epilepsy will not necessarily work for another. Of two people
taking the same drug, one may experience side effects while the
other will not. By the same token, some drugs will reach a therapeutic,
seizure-preventing, level in a patient's bloodstream more quickly
than other drugs.
For these reasons, it may take some time to customize the dosage
and/or choice of drug(s). Doctors try to achieve a balance by
prescribing the medication that offers the greatest degree of
seizure control with the fewest side effects.
Blood level monitoring: antiepileptic drug level testing
helps a physician achieve seizure control by monitoring the presence
of a medication in a patient's bloodstream.
The bloodstream is the pathway to the brain and, therefore, leads
medication to the centres of the brain in which seizures begin.
If a drug's blood level too low, seizures may occur and the dosage
will have to be increased. Conversely, too high a drug level may
cause a patient to experience side effects, such as drowsiness
or confusion. This necessitates a reduction in dosage or, possibly,
a change to a different medication.
Drug level testing should be performed during the course of a
treatment program, and again when good seizure control has been
established. Subsequent tests are carried out if there are changes
in control, or if side effects occur.
Generic or brand name drugs: Brand name drugs are those
developed by research-oriented phamaceutical companies. These
drugs appear first on the market and their names become widely
known to describe the medication.
The pharmaceutical company that develops a new drug obtains an
exclusive patent to manufacture and distribute that medication
for a certain number of years. When the patent expires, other
companies are free to offer generic versions of the brand name
drug, at lower prices.
Generic drugs contain the same active ingredient as brand name
products, but may be different in color, or in their other non-active
substances, known as excipients. These substances are the fillers,
binders and dyes that give a tablet or capsule its shape, or that
help mask a medication's unpleasant taste.
A change in excipients can change the availability of active drug
to the body for certain medications used in the treatment of epilepsy.
Therefore, it is important to check with your physician or pharmacist
before changing brands of anticonvulsant drugs.
Whether you use a brand name or generic drug, it is important
to be familiar with its color, shape, size and identifying marks.
Caution is needed because dosage instructions can vary between
a brand name drug and its generic equivlent, even though they
have the same active ingredient.
There are even differences between forms of a single brand name
product. The amount of drug absorbed by the body may not be the
same, even if an equal number of milligrams of medication are
consumed. Therefore, any change in medication, be it from a brand
name to generic drug, or between two forms of a brand name product,
should not be undertaken without first consulting you physician
and/or pharmacist.
Drugs and Pregnancy
In recent years thare have been a number of reports indicating
an increased risk of birth defects for women who use seizure controlling
drugs.
Though estimates vary, the average risk appears to be about two
to three times the normal rate, although it may be even higher
for certain drugs or drug combinations. Genetic factors may also
play some role in determining whether a birth defect occurs.
This situation creates a difficult problem for women who have
epilepsy. Medication may increase certain risk factors, but the
need for anticonvulsant drugs continues during pregnancy. In fact,
some pregnant women have more seizures than they would at other
times.
A seizure that occurs during pregnancy presents risks for both
mother and child. The mother's impaired breathing may deprive
the fetus of oxygen, and both may suffer injuries in falls caused
by a seizure-induced loss of consciousness.
A decision to change or stop anticonvulsant medication should,
therefore, only be made after careful discussion of individual
risk factors by a woman, her partner, and the women's physician.
Unfortunately, women whose seizures can only be controlled by
drugs which carry a higher risk of defects may be advised to avoid
pregnancy altogether.
Ideally, discussions of these issues should take place before
a woman becomes pregnant so that, if the decision to change or
slowly withdraw medication is made, the new treatment plan can
be tried out before conception occurs.
A woman who does become pregnant while on antiepileptic drugs
should not simply stop taking her medication. Such a sudden change
in anticonvulsant therapy can cause severe episodes of multiple
seizures that may threaten a woman's pregnancy, or her life. Instead,
she should consult her physician as soon as possible.
A doctor would not normally take a woman off medication, once
a pregnancy had begun, since the baby's key developmental stages
would already have been passed. At the time, the entire gestational
period requires careful monitoring and often calls for adjustments
in medication.
It is important, however, to remember that, despite the increased
risk of birth defects, the overwhelming majority of women with
epilepsy who take anticonvulsant medication during pregnancy (at
least 90 percent of them, by most estimates) give birth to normal,
healthy infants.
Anticonvulsants and children
Early recongnition of seizures, followed by consistent, regular
treatment with anticonvulsant drugs, offers the best chance of
a normal childhood, and a positive future, for the child with
epilepsy.
Regular check-ups are important, even when children are seizure-free,
because the original dose of anticonvulsant drugs may become ineffective
as children grow taller and increase in body weight.
Should a previously seizure-free child begin to have seizures
again, it does not mean that the condition is getting worse, nor
that the medication is no longer appropriate. Usually, a change
in dosage will take care of the problem.
The bodies of children and adults process drugs differently, so
it often takes a proportionally larger dose of anticonvulsant
to control seizures in the average child than in the average adult.
At the onset of puberty, body chemistry changes over from that
of childhood to adulthood, often in a matter of just months. Unless
drug levels are tested, and dosages adjusted accordingly, the
recently-matured adolescent may suddenly be taking more medication
than his or her body can handle. He, or she, may become drowsy
and find it difficult to do school work. Over-medication can be
easily avoided by periodic check-ups and drug level tests as youths
on anticonvulsants approach sexual maturity.
Depending on their social maturity, children should be encouraged
to be responsible for taking their own medicine, as early as possible.
In most cases, this will give them a greater sense of responsibility,
and of being in control of their condition.
If medication is given in liquid suspension form, as in a syrup,
the bottle must be shaken well before measuring out the dosage.
Otherwise, the active drug may sink to the bottom of the suspension,
making the first doses out of the bottle too weak while the last
ones will be too strong.
In some children, phenobarbital may have the effect of producing
hyperactive, irritable behaviour. In others, performance ability
may be impaired. If these problems arise at home or at school,
a different drug might be prescribed, after discussion with the
treating physician.
Sometimes, the widely-used drug phenytoin(Dilantin) can cause
problems of gum overgrowth, ranging from slight to severe. This
may often be prevented by brushing very carfully, as well as by
regular use of dental floss and frequent professional cleaning.
If gum growth becomes a severe problem, the tissue can be surgically
removed.
Whether a medication is prescribed for children or for adults,
a patient should know whether it is to be taken before, during,
or after meals. Sometimes, medication taken on an empty stomach
can increase the possibility of stomach upset. On the other hand,
taking certain medications after a meal may affect the rate at
which the drug enters the bloodstream.
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Most
Common Antiepileptic Drugs
|
| CLOBAZAM |
| TRADE
NAME: Frisium |
| COMMON
USES: Adjunctive therapy in broad range of seizures, including
atonic, myoclonic infantile spasms, absence. |
| POSSIBLE
SIDE EFFECTS: Sedation, tiredness, muscle weakness, drowsiness,
unsteadiness, irritability, weight gain/loss. |
| UNACCEPTABLE
SIDE EFFECTS: Hypersensitivity, allergic reaction. |
|
| CLONAZEPAM |
| TRADE
NAME: Rivotril |
| COMMON
USES: Adjunctive therapy with atonic, myoclonic, infantile
spasms, absence. |
| POSSIBLE
SIDE EFFECTS: Lethargy, dizziness, nausea/vomiting, increase
in bronchial secretions, weight loss/gain, slurred speech. |
| UNACCEPTABLE
SIDE EFFECTS: Hypersensitivity, allergic reaction. |
|
| DIAZEPAM |
| TRADE
NAME: Valium |
| COMMON
USES: Acute and status epilepticus. |
| POSSIBLE
SIDE EFFECTS: Drowsiness, fatigue, ataxia, also: confusion,
slurred speech, blurred vision, tremors, headache, nausea, depression.
|
| UNACCEPTABLE
SIDE EFFECTS: Allergic rash, hallucinations, rage,
anxiety, muscle spasticity, haematological effects, respiratory
arrest. |
| NOTES:
Used intravenously. Long-term oral use can have disastrous effects.
|
|
| CARBAMAZEPINE |
| TRADE
NAME: Tegretol |
| COMMON
USES: Tonic clonic, simple partial, complex partial. |
| POSSIBLE
SIDE EFFECTS: Drowsiness, dizziness, blurred vision, double
vision, lethargy, nausea/vomiting, change in liver function. |
| UNACCEPTABLE
SIDE EFFECTS: Hypersensitivity, allergic reaction, impairred
liver function, low white blood cell count. |
| NOTES:
Affects birth control pill; appears safer than others re: birth
defects; relatively free of behavioral effects versus Dilantin,
Phenobarb. |
|
| ETHOSUXIMIDE
(SUCCINIMIDE) |
| TRADE
NAME: Zarontin |
| COMMON
USES: Absence. |
| POSSIBLE
SIDE EFFECTS: Drowsiness, hyperactivity, nausea/vomiting,
sleep disturbance. |
| UNACCEPTABLE
SIDE EFFECTS: Hypersensitivity, allergic reaction. |
|
| FELBAMATE |
| TRADE
NAME: Felbatol |
| UNACCEPTABLE
SIDE EFFECTS: Aplastic anemia |
| NOTES:
Use not recommended. |
|
| GABAPENTINE |
| TRADE
NAME: Neurontin |
| COMMON
USES: Simple partial, complex partial, secondarily generalized
tonic clonic. |
| POSSIBLE
SIDE EFFECTS: Drowsiness, dizziness, fatigue, clumsiness,
weakness, trembling, increased appetite/weight gain. |
| UNACCEPTABLE
SIDE EFFECTS: CNS toxicity, vision disturbances, Rhinitis,
Pharyngitis. |
|
| LAMOTRIGINE |
| TRADE
NAME: Lamictal |
| COMMON
USES: Simple partial, complex partial, generalized-(Limited
studies). |
| POSSIBLE
SIDE EFFECTS: Ataxia, diplopia (blurred vision), sedation,
dizziness. |
| UNACCEPTABLE
SIDE EFFECTS: Allergic reaction. |
| NOTES:
Currently not recommended under age of 18 - serious skin reactions
more likely. |
|
| PHENOBARBITAL
(BARBITURATE) |
| TRADE
NAME: Phenobarb |
| COMMON
USES: Myoclonic, effective but unacceptable toxicities with
partial and tonic clonic. |
| POSSIBLE
SIDE EFFECTS: Lethargy, drowsiness, hyperactivity, mood
changes, depression, behavioral/learning problems. |
| UNACCEPTABLE
SIDE EFFECTS: Hypersensitivity, allergic reaction. |
| NOTES:
Affects birth control pill; same problems as phenytoin, but
slightly less risk. |
|
| PRIMIDONE
(Form Phenobarbital in body) |
| TRADE
NAME: Mysoline |
| COMMON
USES: Effective but unacceptable with toxicities with: tonic
clonic, simple partial, complex partial. |
| POSSIBLE
SIDE EFFECTS: Drowsiness, appetite loss, irritability, nausea,
dizziness, loss of coordination, hyperactivity, mood or personality
changes, depression. |
| UNACCEPTABLE
SIDE EFFECTS: Hypersensitivity, allergic reaction. |
| NOTES:
Increased risk of birth defects. |
|
| PHENYTOIN |
| TRADE
NAME: Dilantin |
| COMMON
USES: Tonic clonic, simple partial, complex partial |
| POSSIBLE
SIDE EFFECTS: Body hair increase, gum overgrowth, tremor,
anemia, loss of coordination, double vision, nausea/vomiting,
confusion,slurred speech. |
| UNACCEPTABLE
SIDE EFFECTS: Hypersensitivity, allergic reaction. |
| NOTES:
Affects birth control pill; 5% risk of birth problems including
cleft palate, congenital heart disease. |
|
| TOPIRAMATE |
| TRADE
NAME: Topamax |
| COMMMON
USES: Adjunctive therapy with partial and secondary generalized;
may be effective with absence; monotherapy trials underway.
|
| POSSIBLE
SIDE EFFECTS: Difficulty concentrating, drowsiness, dizziness,
loss of coordination, weight loss. |
| UNACCEPTABLE
SIDE EFFECTS: Allergic reaction, 1.5% incidence of kidney
stones. |
| NOTES:
Few significant interactions with traditional AEDs. |
|
| VALPROIC
ACID |
| TRADE
NAME: Depakene |
|
| DIVALPROEX
SODIUM (Forms Valproic Acid in body) |
| TRADE
NAME: Epival |
| COMMMON
USES: Atonic, myoclonic, infantile spasms, absence, tonic
clonic, partial - (somewhat effective). |
| POSSIBLE
SIDE EFFECTS: Nausea/vomiting, indigestion, sedation, dizziness,
hair loss, tremor, changes in liver function, weight gain, loss
of coordination. |
| UNACCEPTABLE
SIDE EFFECTS: Hypersensitivity, allergic reaction, impaired
liver function, low blood platelet count, stupor, coma. |
| NOTES:
1 to 2% increased risk of spina bifida and other birth problems. |
|
| VIGABATRIN |
| TRADE
NAME: Sabril |
| COMMMON
USES: Atonic, simple and complex partial; shown some promise
with infantile spasms and other complicated seizure disorders.
|
| POSSIBLE
SIDE EFFECTS: Blurred vision, drowsiness, weakness tiredness
increased appetite, hyperacitivity, depression, dizziness, headache. |
| UNACCEPTABLE
SIDE EFFECTS: Allergic reaction. |
| NOTES:
Should not be used if pregnant or lactating. |
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