Topamax’s mechanism of action is unclear. We do know that the drug blocks sodium channels that deliver electrical impulses to nerve, muscle, brain, and other excitable cells. By doing so, Topamax appears to enhance the activity of a chemical messenger (neurotransmitter) known as gamma-aminobutyric acid (GABA). Topamax is available in capsule and tablet formulations. The tablet is offered in 25-, 50-, 100-, and 200-milligram (mg) formulations. The capsule is available in 15 mg and 25mg. The dosage varies with the person’s condition and age. Topamax has both approved and off-label uses. The U.S. Food and Drug Administration (FDA) has approved it for:
Migraine prevention in adults and adolescents 12 and olderPartial-onset seizure treatment in adults and children 2 and olderPrimary generalized tonic-clonic seizure treatment in adults and children 2 and older
Topamax can also be combined with other drugs to treat partial-onset seizures, primary generalized tonic-clonic seizures, and seizures associated with Lennox-Gastaut syndrome (a severe form of childhood epilepsy).
Off-Label Uses
Among topiramate’s off-label uses is treatment for:
Alcohol dependency Bipolar disorder Borderline personality disorder (BPD) Depression Post-traumatic stress disorder (PTSD) Tourette syndrome Weight loss (specifically to control binge-eating and purging)
How to Take Topamax
At the beginning of treatment, your healthcare provider typically will increase your dosage gradually to reduce the risk of side effects. The medication takes approximately five days to build up and reach a steady state in your system.Your healthcare provider will tell you how to taper down your dosage gradually if you decide together to stop using it. Don’t stop taking it abruptly on your own; this can cause a rebound of disease symptoms (such as seizures in people with epilepsy or abnormal moods in people with bipolar disorder).
Storage
Store Topamax at room temperature, out of direct light, and away from heat and moisture in a closed container.
What Are the Side Effects of Topamax?
Side effects of topiramate tend to be transient and resolve on their own as your body adapts. Common/mild side effects include:
Breast pain in womenTremorsConstipationWarmthHeartburnincreased sweatingRedness of the face, neck, arms, or upper chest
Consult your healthcare provider if you notice any of the following:
Aggression, anger, agitation, irritabilityBack-and-forth or rolling eye movementsBurning or tingling sensationsChest painChillsConfusionDecreased sexual performance or libidoDifficulty speakingDrowsinessDulled sensations or perceptionFeverIncreased fatigue or weaknessIrritated gumsLack of appetiteLack of emotionLack of interest or pleasure in things you ordinarily enjoyMemory or concentration problemsMenstrual issuesSlowed thinking or movementSore throatStomach painTrouble sleepingUnsteadiness or dizzinessVision problemsWeight loss
Dosage: How Much Topamax Should I Take?
Your provider will determine the best dosage for you based on several factors, including your weight, condition, other medications, age, and contraindications. Generally, this will be the lowest dosage that’s likely to provide the desired results. Usually, you’ll begin with a low dose, which your doctor will slowly raise until it reaches the optimum for your condition. This gives your body time to adapt and reduces the risk of side effects.
Modifications
When prescribed for young children, the Topamax capsule can be broken open and its contents sprinkled over food.
Missed Dose
If you forget to take Topamax, take it as soon as you remember, unless it’s close to your next dose time. In that case, skipped the missed dose and then resume your usual dosing schedule. Don’t ever take more than one dose at a time. If you miss more than one dose, consult your healthcare provider. You’ll probably have to restart your treatment regimen.
Overdose: What Happens If I Take Too Much Topamax?
Symptoms of a topiramate overdose include:
Lessened responsiveness or awarenessDizziness, fainting, or lightheadedness upon standing upSevere fatigue or drowsinessSluggishness
Seek help immediately if you think you’ve taken too much Topamax.
Precautions
When deciding on any medical treatment, healthcare providers weigh risks vs. benefits. If your doctor has prescribed Topamax, they’ve determined that the potential good it can do for you outweighs any possible negative issues. Still, some precautions are in order. Here are a few:
Wait to see how you feel when you take Topamax before you drive, swim, use dangerous equipment, or do anything else that requires balance, good vision, or focus.Check with your practitioner before you take any other medicines, whether prescribed or over the counter. Even common medications such as cold remedies can change the way Topamax affects you.Topamax can cause you to sweat less than usual. If you’re taking a hot shower or doing anything else that could increase your body temperature, stop if you feel woozy or sick. Tell your doctor if you feel irritated, angry, anxious, or any other unusual way. Some people become depressed or suicidal when starting this medication. If you notice symptoms like this or experience strong emotions, develop insomnia, feel violent, or feel otherwise strange, contact your healthcare provider immediately.Avoid alcohol and recreational drugs. Combining them with Topamax can cause serious interactions.
What Are Reasons I Should Not Take Topamax?
Although it’s not common, Topamax can cause serious complications that require you to stop or avoid treatment. Among them are:
Glaucoma. In some individuals, Topamax can cause glaucoma, symptoms of which usually appear within a month of starting treatment. These include sudden blurring of vision, eye pain, redness, and dilated pupils.Kidney damage. This most often affects people over 65 who have an underlying kidney disorder. Your doctor should test your kidney function routinely. Kidney stones have been known to develop in Topamax users; drink plenty of water to reduce this possibility.Metabolic acidosis. Topamax can cause this potentially serious buildup of acid in the blood, most often in children 15 and under. Symptoms include nausea, vomiting, fast breathing, and lethargy. Left untreated, metabolic acidosis can lead to coma and death.Pregnancy. Topamax can cause issues for the fetus, including a cleft palate and small gestational size. It also can pass into breastmilk. Although Topamax is not necessarily contraindicated, you must weigh the benefits and consequences of treatment if you are pregnant, planning to get pregnant, or breastfeeding.
What Other Medications Interact With Topamax?
Certain drugs reduce or increase the availability of Topamax. This is especially true when it’s used with other anticonvulsants such as Tegretol (carbamazepine) and Lamictal (lamotrigine). Your doctor might have to adjust your dosage to compensate. Other co-administered drugs that can require dose adjustments include the diuretic Microzide (hydrochlorothiazide) and the diabetes medications Actos (pioglitazone) and metformin. Avoid taking carbonic anhydrase inhibitors, which include:
Diuretics such as Keveyis (dichlorphenamide)Epilepsy drugs such as Diamox (acetazolamide) and Zonegran (zonisamide)Glaucoma medications such as Azopt (brinzolamide), Neptazane (methazolamide), and Trusopt (dorzolamide)
Topamax also can reduce the efficacy of estrogen-based contraceptives, increasing the risk of pregnancy and breakthrough bleeding.
What Medications Are Similar?
A wide variety of Topamax alternatives is available, depending on the condition for which you take it. Consult your healthcare provider if you’d rather take a different medication.
How Can I Stay Healthy While Taking Topamax?
Just as you would with any other medications, follow the usual guidelines for healthful eating, exercise, sleep, etc. to help Topamax do its work. Avoid ketogenic diets while you’re taking Topamax to minimize the risk of kidney stones. Drink lots of fluids. Topamax can reduce the efficacy of oral contraceptives, so consider using additional methods as backup.
