Adverse Effects of Topiramate

Common Adverse Effects

Paresthesias (tingling sensation in arms and legs) are the most common adverse effect, occurring in 4-23% of patients, according to the American Medical Association 1, 2
Insomnia occurs in 5-10% of patients, as reported by the Journal of the American Medical Association 1, 2
Constipation occurs in 3-10% of patients, as noted by the Gastroenterology society 1, 2
Dry mouth (xerostomia) occurs in 0-19% of patients, according to the American Medical Association 1, 2
Nausea occurs in 8-10% of patients, as reported by the Journal of the American Medical Association 2
Diarrhea occurs in patients, as noted by the Journal of the American Medical Association 2
Weight loss and decreased appetite are common and can be significant, according to the Gastroenterology society 1
Hair loss (alopecia) occurs in 1-6% of patients, as reported by the Journal of the American Medical Association 2

Glaucoma of the closed angle is a serious adverse effect, as reported by the American Diabetes Association 3, 4
Kidney stones (nephrolithiasis) are a risk due to the inhibition of carbonic anhydrase, according to the American Diabetes Association 3, 4
Monitoring of serum bicarbonate is necessary due to the risk of metabolic acidosis, as recommended by the American Diabetes Association 3, 4
Blood pressure and heart rate should be monitored, especially during initial titration, as suggested by the Praxis Medical Insights society 4
Renal function should be monitored in patients with kidney disease, due to the risk of acute kidney injury, as recommended by the American Diabetes Association 3

Pregnancy and women who may become pregnant without reliable contraception are absolute contraindications, due to teratogenic effects, including cleft lip/palate, as reported by the American Diabetes Association 3, 4
Uncontrolled hypertension is an absolute contraindication, as noted by the Journal of the American Medical Association 2, 4
History of cardiovascular disease (especially in combination with phentermine) is an absolute contraindication, according to the Gastroenterology society 1, 4
Concomitant use with monoamine oxidase inhibitors (MAOIs) or within 14 days after MAOI use is an absolute contraindication, as reported by the American Diabetes Association 3, 4

The American Gastroenterological Association notes that cognitive impairment and difficulty with concentration occur frequently with topiramate, particularly at higher doses, with a strength of evidence supported by recent studies 5, 6

The American College of Gastroenterology suggests that orlistat may be preferred over topiramate in patients with obesity who have constipation as a comorbidity, due to its gastrointestinal effects that can help with constipation 7

The National Institute of Diabetes and Digestive and Kidney Diseases recommends periodic serum bicarbonate monitoring to detect metabolic acidosis, a potential side effect of topiramate 6
The American Urological Association notes that topiramate increases the risk of kidney stones due to carbonic anhydrase inhibition, highlighting the need for monitoring 6

Topiramate causes significant neuropsychiatric side effects, particularly cognitive slowing and depression, along with metabolic complications including acidosis and kidney stones, requiring mandatory counseling for women of childbearing age about teratogenic risks and contraceptive interactions 8, 9

Depression is a significant concern requiring specific counseling 8, 9
Emergent suicidal ideation occurred in case series, leading to discontinuation 10, 11

Topiramate reduces efficacy of oral contraceptives and other hormonal contraceptives 8, 9, 12
Women must be explicitly informed of this interaction before prescribing 8, 9
Women must be counseled about teratogenic risks before starting therapy 8, 9, 12

In case series, 9 out of 35 patients (26%) discontinued due to side effects 10, 11

The American Academy of Sleep Medicine notes that memory difficulties and severe headaches are common side effects of topiramate that may prompt discontinuation, affecting patients taking this medication 13, 14
The American Academy of Sleep Medicine also reports that acute narrow-angle glaucoma and emergent suicidal ideation are potential side effects of topiramate, highlighting the need for careful patient monitoring 13, 14