OverviewDosageSide EffectsInteractionsHalf-Life

As is the case with any other medication, there may be some instances where Topamax interactions can occur. In such cases, use is not recommended or usage will have to be adjusted in order to prevent or reduce the risk of negative interactions occurring from other drugs, medical conditions, or even food and drink.

Drug Interactions

According to the FDA, drugs that may interact with Topamax include the following:

  • Encephalopathy may occur when Topamax and valproic acid are both used. When Topamax and carbamazepine or phenytoin are both used, this can cause a significant decrease in the amount of Topamax in plasma, which may reduce its effects.
  • Other carbonic anhydrase inhibitors, as the use of both Topamax and these medications may raise the risk of kidney stones and increase the risk of severe metabolic acidosis.
  • CNS depressants, as the use of Topamax with these medications has not been studied, and Topamax may increase the risk of CNS depression and other cognitive adverse reactions.
  • Oral contraceptives, as the use of these medications and Topamax may decrease the effectiveness of contraceptives and increase the risk of breakthrough bleeding.
  • Hydrochlorothiazide (HCTZ), as the use of HCTZ and Topamax may increase the area under the curve, which can affect the clearance rate and extent of exposure to Topamax.
  • Pioglitazone, as the use of both medications may decrease the effectiveness of pioglitazone’s anti-diabetic effects in patients with diabetes.
  • Lithium, as the use of Topamax at certain dosages may raise the systemic exposure of lithium.
  • Amitriptyline, as the use of Topamax may lead to a significant increase in amitriptyline levels.

Please note that this list may not be complete, and other interactions with drugs not listed here may occur.

Hormonal Birth Control

Taking Topamax may lower the effectiveness of hormonal birth control, such as oral contraceptives containing estrogen. Combining hormonal birth control with Topamax may also increase the risk of breakthrough bleeding.

Adderall

No interactions between Topamax and Adderall have been found. Individuals should discuss any concerns they have about taking both of these medications with their doctor.

Wellbutrin (Bupropion)

Interactions between Wellbutrin and Topamax have not been found. Those taking both should talk to their doctor if they have any concerns.

Vyvanse (Lisdexamfetamine)

Topamax may increase drowsiness and sedation, while Vyvanse may decrease drowsiness and sedation. Those taking both medications should be monitored closely.

Sumatriptan (Zembrace Symtouch, Onzetra Xsail, Sumavel DosePro)

No interactions between Sumatriptan and Topamax have been found. Those who take both medications should discuss concerns with their doctor.

Marijuana (THC)

The use of marijuana and Topamax may increase drowsiness. Those who use both should avoid driving or using heavy machinery due to this effect. Topamax has been used to help treat marijuana dependence, but individuals in those studies had a difficult time with the side effects of this medication, such as depression, coordination problems, and anxiety. More research is needed to understand the effects of Topamax and THC use.

Phentermine

Topamax may raise the levels of phentermine in the blood and increase its effects. Individuals taking both should see a doctor right away if they experience more severe side effects, such as restlessness, headache, dizziness, heart palpitations, or elevated blood pressure.

Zoloft (Sertraline)

The use of Zoloft and Topamax may lead to blood sodium levels that are too low, resulting in a condition called hyponatremia. Zoloft might also increase the risk of seizures, which may reduce the effectiveness of Topamax. Individuals should discuss these risks with their doctor before taking both medications.

Gabapentin (Gralise)

No interactions between gabapentin and Topamax have been found. Those taking both should discuss concerns with their doctor.

Food Interactions

Sometimes the foods we eat and the beverages we drink can also interact with our medications. Food and drink that may interact with Topamax include:

  • Alcohol, as this combination may increase certain effects, such as drowsiness and confusion.

Please note that this list may not be complete, and there may be other foods and beverages that interact with this drug.

Topamax and Alcohol

For more information, please visit our page on Topamax and alcohol interactions.

Vitamins

No interactions between specific vitamins and Topamax have been found. However, individuals should let their doctor know about any vitamins or supplements they are taking while using Topamax.

Disease & Conditions Interactions

Sometimes certain medications can increase the risk of negative side effects for patients with certain diseases or other medical conditions. According to the FDA, diseases and medical conditions that are known to negatively interact with Topamax include:

  • Bone marrow depression or blood dyscrasias
  • Liver disease or cirrhosis
  • Renal dysfunction
  • Metabolic acidosis
  • Angle closure glaucoma, intraocular hypertension, or myopia
  • Hemodialysis
  • Nephrolithiasis

Please note that this list may not be complete, and there may be other diseases and medical conditions where patients should not take this medication.

Weight Loss

Weight loss has been reported as an adverse effect in some individuals who take Topamax, based on clinical trials. Weight loss was reported more often among those who took higher doses of this medication.

Topamax and Pregnancy

For more information, please visit our page on Topamax and pregnancy risks.

Breastfeeding

For more information, please visit our page on Topamax and pregnancy risks.

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.


More about Topamax

Written by

Medically reviewed by