I. Topamax Fact File
Topamax is produced by Ortho-McNeil Pharmaceutical. Topamax received U.S. Food and Drug Administration (FDA) approval in March 1995.
Ortho-McNeil is one of the largest companies within the Johnson & Johnson Family of Companies.
II. Topamax Medication
Topamax medication is an antiseizure (anticonvulsant) medicine that has been used by approximately 3.5 million people worldwide. Scientific evidence shows that Topamax medication can be combined with other antiseizure medicines to control partial-onset and primary generalized tonic-clonic seizures, as well as seizures associated with Lennox-Gastaut syndrome in adults and children as young as 2 years of age.
Generic Topamax is the first medicine for migraine prevention. Topamax medication is approved for migraine prevention in adults only. The usefulness of Topamax medication in the acute treatment of migraine headache has not been studied.
Generic Topamax has been proven in well-controlled clinical trials to help reduce significantly the number of migraines patients have.
Anticonvulsants: Information
Anticonvulsants are a family of drugs that depress abnormal nerve activity in the brain, thereby blocking seizures. Barbiturates and benzodiazepines are commonly used to prevent and treat seizure disorders, as well as other conditions. Though some people are maintained on a single drug, most take two or more anticonvulsant medications to prevent seizures. Consequently, many studies report interactions that occur in individuals taking several anticonvulsants.
Medications can be divided into older medications (called first-generation anticonvulsants) and more recently developed medications (second-generation anticonvulsants).
First-Generation anticonvulsants
Phenytoin (Dilantin®): Phenytoin is one of the more commonly used agents and often is considered the first-line drug to treat partial and generalized tonic-clonic (grand mal) seizures and status epilepticus.
Phenytoin (Dilantin) 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.
Carbamazepine (Tegretol®/Carbatrol®): Carbamazepine drug is commonly prescribed for the treatment of partial and generalized tonic-clonic (grand mal) seizures. The mechanism by which it works is not well understood. In oral form, it can be taken 2 to 3 times a day; a recent development of the drug in sustained-release form allows for twice-a-day dosing.
Phenobarbital: Phenobarbital drug is used to treat both partial and generalized seizures. It also is used as part of the protocol after phenytoin use in status epilepticus as well as in neonatal epilepsy. It is available in oral and intravenous forms.
Valproate (Depakote®): Valproate drug is prescribed for partial seizures, generalized tonic-clonic (grand mal) seizures, absence (petit mal) seizures, and myoclonic epilepsy. Its mechanism of action is thought to be related to the effect of a brain substance known as GABA (gamma-aminobutyric acid). It is available in oral form and must be taken 2 to 3 times per day for adequate dosing.
Second-Generation anticonvulsants
Topiramate (Topamax®): Topiramate drug is used with other anticonvulsant drugs in the treatment of partial seizures and generalized tonic-clonic seizures in adults and children aged 2 to 16. Its precise mechanism of action is unknown, but its anticonvulsant activity may be due in part to increasing GABA (gamma-aminobutyric acid), a neurotransmitter that inhibits excitation of nerve cells in the brain. It is available in oral form, including sprinkles for children, and is taken twice daily. There are few drug interactions between topiramate and other medications or other anticonvulsants.
Gabapentin (Neurontin®): Gabapentin drug is indicated for the adjunct treatment of partial seizures, with or without secondary generalization. Although it is structurally related to the substance GABA (gamma-aminobutyric acid), it does not interact with GABA receptors in the brain, and its mechanism of action is unknown. It is available in oral form and is taken 3 times daily.
Lamotrigine (Lamictal®): Lamotrigine drug is used for the adjunct treatment of partial seizures. Its precise mechanism of action is unknown. It is presently available in oral form and is taken twice daily. No laboratory monitoring of drug levels are necessary.
Tiagabine (Gabitril®): Tiagabine drug is indicated for adjunct therapy in adults with partial seizures. Its mechanism of action may be related to its effect on the brain substance GABA (gamma-aminobutyric acid). It is available in oral form and should be given in divided doses 2 to 4 times daily. Its metabolism may be altered when taken with other anticonvulsants.
Levetiracetam (Keppra®): Levetiracetam drug is approved for use in adults as adjunct therapy for the treatment of partial seizure disorders. It is available in tablet form and as an oral solution for patients who prefer a liquid or cannot swallow tablets. Side effects can include fatigue, imbalance, and behavioral changes, which often dissipate after the first month of treatment.
Oxcarbazepine (Trileptal®): Oxcarbazepine drug is indicated for monotherapy (used alone) and adjunct therapy (in addition to other medications) in adults who have partial seizures and as adjunct therapy in children aged 4 and older who have partial seizures. When used as monotherapy, Trileptal causes very few of the side effects associated with other AEDs.
Zonisamide (Zonegram®): Zonisamide drug is approved for use in adults as adjunct therapy for partial seizures. It has however, been used fairly extensively in other countries for use in other seizure types including generalized seizures, myoclonic seizures, and absence seizures. Patients who are allergic to sulfonamide drugs should not use zonisamide because it is a derivative of this class of drug.
Ethosuximide (Zarontin®) : Ethosuximide drug agent is used to treat absence (petit mal) seizures. It is thought to work by suppressing brain cell activity that is associated with lapses of consciousness. It is given orally and is available as a tablet or flavored syrup.
Primidone (Mysoline®) : Primidone drug is a barbiturate that contains phenobarbitol. It is used to control generalized tonic-clonic (grand mal) seizures and partial seizures and is used in adults and children over 8 years old. Primidone is not known to interact with other drugs. It is present in breast milk and is associated with neonatal hemorrhage and coagulation defects similar to vitamin K deficiency. Patients hypersensitive to phenobarbital should not take primidone.
Epilepsy: Information
Epilepsy is the tendency to have repeated seizures that begin in the brain. Epilepsy is a physical condition that starts in the brain - a neurological condition. Epilepsy is a symptom that the way a person's brain works is sometimes disrupted. When this happens, a person may suddenly have a seizure. Many people will have a single seizure at some time in their lives, but this does not mean that they have epilepsy. If a person has epilepsy it means they have had more than one seizure that began in the brain.
Our brains: The human brain is a complex structure made up of millions of nerve cells called neurones. Our brain controls a wide range of tasks such as consciousness, awareness, movement, and posture. The brain sends and receives messages to make these tasks happen. If there is a mistake sending or receiving messages, a brief break in some or all of the brain's tasks can happen. If this happens a person may have a seizure.
Seizures: Seizures can happen for many different reasons. A person with diabetes may have a diabetic seizure if their blood sugar level is too high. A person with epilepsy has an epileptic seizure if their usual brain activity is suddenly disturbed.
Some people call their seizures by a different name - such as a fit, funny turn, attack or blackout. Seizures can be of two types - generalised or partial. What you experience (your symptoms) will depend on where the change in brain activity begins and how widely and rapidly it spreads out. Generalized seizures involve the whole brain. There are several types, including - tonic-clonic, absence and myoclonic.
Partial seizures, as the name suggests, start in just one part of the brain. They can be either simple partial seizures or complex partial seizures but either way the electrical discharge may stay in one spot or may spread to the rest of the brain.
Possible causes of seizures - the triggers
Most seizures strike completely out of the blue. However some of us can pinpoint certain factors which spark them off. These include:
Alcohol - Having excess alcohol can trigger a seizure - even in people without epilepsy.
Stress - some people experience more seizures during periods of anxiety or stress. This may be partly because sleep patterns can be upset at such times. Some stress is part of everyday life - it's best to find ways to manage it, rather than trying to avoid it altogether.
Patterns of light - many people believe that watching TV or playing video games can trigger a seizure. This is true in a few people who are photosensitive (sensitive to flickering light), though it's far less common than most people imagine. In fact only about five per cent of people with epilepsy are affected in this way.
Late nights & lack of sleep - People with too many late nights or going without sleep (e.g. if you work shifts or travel across time zones) can cause seizures. The odd late night shouldn't matter much, but it is best to try to keep regular hours. Experience will teach you what best suits you.
Illness - A very high temperature (fever) can bring on a seizure in young children if they are ill. This is less likely in adults, however having a minor ailment can reduce a person's seizure threshold, making seizures more likely.
Hormones - Many women report that their seizures are linked to their menstrual cycle - though no one really knows why. They tend to happen in the week before or first few days of your your period. Ask your doctor or medical specialist for advice if you are affected in this way.
Food - Some people with epilepsy claim that certain foods trigger seizures. There is no evidence to suggest that people with epilepsy should avoid certain foods. However, skipping meals and eating an unbalanced diet may be a factor.
Migraine: Information
A migraine is a throbbing or pulsating headache that is often one sided (unilateral) and associated with nausea; vomiting; sensitivity to light, sound, and smells; sleep disruption; and depression. Attacks are often recurrent and tend to become less severe as the migraine sufferer ages.
Causes of Migraine
The cause of migraine is unknown. The condition may result from a series of reactions in the central nervous system caused by changes in the body or in the environment. There is often a family history of the disorder, suggesting that migraine sufferers may inherit sensitivity to triggers that produce inflammation in the blood vessels and nerves around the brain, causing pain.
Triggers : A trigger is any stimulus that initiates a process or reaction. Commonly identified migraine triggers include the following:
- Alcohol (e.g., red wine)
- Environmental factors (e.g., weather, altitude, time zone changes)
- Foods that contain caffeine (e.g., coffee, chocolate), monosodium glutamate (MSG; found in Chinese food), and nitrates (e.g., processed foods, hot dogs)
- Glare
- Hormonal changes in women
- Hunger
- Lack of sleep
- Medications (over-the-counter and prescription)
- Perfume
- Stress
Signs and Symptoms of Migraine
Migraine pain is often described as throbbing or pulsating pain that is intensified by routine physical activity, coughing, straining, or lowering the head. The headache is often so severe that it interferes with daily activity and may awaken the person. The attack is debilitating, and migraine sufferers are often left feeling tired and weak once the headache has passed.
A migraine typically begins in a specific area on one side of the head, then spreads and builds in intensity over 1 to 2 hours and then gradually subsides. It can last up to 24 hours, and in some cases, several days.
There may be accompanying symptoms such as nausea, vomiting, sensitivity to light (photophobia), or sensitivity to sound (phonophobia). Hands and feet may feel cold and sweaty and unusual odors may be intolerable.
Types of Migraine
Migraines are classified according to the symptoms they produce. The two most common types are migraine with aura and migraine without aura.
Less common types include the following:
Migraine with aura is characterized by a neurological phenomenon (aura) that is experienced 10 to 30 minutes before the headache. Most auras are visual and are described as bright shimmering lights around objects or at the edges of the field of vision (called scintillating scotomas) or zigzag lines, wavy images, or hallucinations. Others experience temporary vision loss.
Nonvisual auras include motor weakness, speech or language abnormalities, dizziness, vertigo, and tingling or numbness (parasthesia) of the face, tongue, or extremities.
Migraine without aura is the most prevalent type and may occur on one or both sides (bilateral) of the head. Tiredness or mood changes may be experienced the day before the headache. Nausea, vomiting, and sensitivity to light (photophobia) often accompany migraine without aura.
Basilar artery migraine involves a disturbance of the basilar artery in the brainstem. Symptoms include severe headache, vertigo, double vision, slurred speech, and poor muscle coordination. This type occurs primarily in young people.
Carotidynia , also called lower-half headache or facial migraine, produces deep, dull, aching, and sometimes piercing pain in the jaw or neck. There is usually tenderness and swelling over the carotid artery in the neck. Episodes can occur several times weekly and last a few minutes to hours. This type occurs more commonly in older people.
Headache-free migraine is characterized by the presence of aura without headache. This occurs in patients with a history of migraine with aura.
Ophthalmoplegic migraine begins with a headache felt in the eye and is accompanied by vomiting. As the headache progresses, the eyelid droops (ptosis) and nerves responsible for eye movement become paralyzed. Ptosis may persist for days or weeks.
Status migraine is a rare type involving intense pain that usually lasts longer than 72 hours. The patient may require hospitalization.
Side effects of anticonvulsants
Side effects associated with phenytoin include:
- Anemia
- Excessive hair growth (hirsuitism/hypertrichosis)
- Imbalance
- Lethargy
- Overgrowth of the gums (gingival hyperplasia)
- Peripheral weakness (neuropathy) with long-term use
Side effects include of Carbamazapine drowsiness, imbalance, nausea, anemia, and low, white blood cell count (neutropenia).
Possible side effects of Phenobarbital include drowsiness, cognitive impairment, and irritability.
Side effects of Valproate include liver damage (hepatotoxicity), nausea, weight gain, hair loss (alopecia), and tremor.
Side effects of Topiramate include drowsiness, nausea, dizziness, and coordination problems. Children may have difficulty concentrating and may become aggressive. Acute glaucoma and visual abnormality, a potentially very serious complication, has been reported in a small number of patients. If abnormal visual symptoms occur, patients should notify a physician immediately.
Side effects of Gabapentin include fatigue, dizziness, and imbalance.
Side effects of Lamictal include headache, nausea, dizziness, and skin rash. The appearance of the potentially life-threatening skin rash, particularly for patients who also are taking valproate (Depakote®), should be reported immediately to a physician.
Side effects of Tigabine include dizziness and somnolence.
Side effects of Oxcarbazepine are usually mild or moderate and include the following:
- Abdominal pain, nausea, vomiting
- Dizziness
- Double vision
- Drowsiness, fatigue
- Loss of coordination, abnormal gait
Side effects of Zonisamide can include dizziness, imbalance, and fatigue.
Potential side effects produced by ethosuximide include the following:
- Gastrointestinal-nausea and vomiting, abdominal pain, cramps, diarrhea, weight loss
- Genitourinary-vaginal bleeding, blood in urine (microscopic hematuria)
- Hematological-bone marrow suppression
- Integumentary-excessive hair growth (hirsutism ), skin rash, systemic lupus erythematous (SLE)
- Neurologica-headache, dizziness, sleep disturbances, aggression, incoordination, fatigue, inability to concentrate
Potential side effects pf Primidone include:
- Blurred vision
- Fatigue
- Incoordination
- Nausea and vomiting
- Sexual impotence (erectile dysfunction)
- Vertigo
- Weight loss
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III. Useful links
Government http://www.cdc.gov/
http://www.fda.gov/
http://www.fda.gov/cder/ogd/
http://www.nih.gov/
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi
http://www.health.gov.on.ca/
National Library of Medicine
World Health Organization
Health Sites
http://www.mayoclinic.com/index.cfm
MedicineNet.com
Drugdigest.org
Healthsquare.com
Pharmacy sites
http://www.orthomcneil.com
http://www.hsforum.com/stories/storyReader$1509 ,
http://www.hsforum.com/stories/storyReader$1516
http://www.hsforum.com/stories/storyReader$1504,
http://www.people.vcu.edu/~urdesai/atc.htm#Process%20of%20clotting
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