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5 Interactions found for:

Topamax and Synthroid
Interactions Summary
  • 2 Major
  • 1 Moderate
  • 2 Minor
  • Topamax
  • Synthroid

Drug Interactions

No drug interactions were found for selected drugs: Topamax, Synthroid.

This does not necessarily mean no interactions exist. Always consult your healthcare provider.

Drug and Food Interactions

Moderate
Synthroid + Food

The following applies to the ingredients: Levothyroxine (found in Synthroid)

The timing of meals relative to your levothyroxine dose can affect absorption of the medication. Therefore, levothyroxine should be taken on a consistent schedule with regard to time of day and relation to meals to avoid large fluctuations in blood levels, which may alter its effects. In addition, absorption of levothyroxine may be decreased by foods such as soybean flour, cotton seed meal, walnuts, dietary fiber, calcium, and calcium fortified juices. These foods should be avoided within several hours of dosing if possible. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

When levothyroxine is given during continuous enteral nutrition (tube feedings) for more than 7 days, the tube feeding should be interrupted for at least one hour before and one hour after the dose of levothyroxine. You may need more frequent blood tests to monitor levothyroxine levels.

The following applies to the ingredients: Levothyroxine (found in Synthroid)

Using multivitamin with minerals together with levothyroxine may decrease the effects of levothyroxine. You should separate the administration of levothyroxine and multivitamin with minerals by at least 4 hours. If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Drug and Pregnancy Interactions

The following applies to the ingredients: Topiramate (found in Topamax)

Professional Content

Use only if clearly needed and benefit outweighs potential risk

AU TGA pregnancy category: D
US FDA pregnancy category: Not assigned

Risk Summary: This drug can cause fetal harm when administered to pregnant women. Data from a pregnancy registry and several epidemiologic studies have shown that infants exposed in utero have an increased risk for cleft lip and/or cleft palate (oral clefts) and for being small for gestational age; in multiple animal species, this drug has demonstrated developmental toxicity, including increased incidences of fetal malformations at clinically relevant doses.

Comments:
-If a patient becomes pregnant during therapy, she should be informed of the potential hazard to her fetus; women of childbearing potential should be counseled on the use effective contraception.
-Women of childbearing potential on antiepileptic drug therapy should receive pregnancy counseling regarding the risk of fetal abnormalities. Generally, antiepileptic therapy should be continued during pregnancy, with monotherapy at the lowest effective dose whenever possible. Folic acid supplementation (5 mg) should be commenced four weeks prior to and continued for 12 weeks after conception. Women should be followed by a specialist and offered detailed mid-trimester ultrasound.
-Pregnancy Registry: The North American Antiepileptic Drug (NAAED) Pregnancy Registry collects information about the safety of antiepileptic drugs during pregnancy; enrollment information: toll-free 1-888-233-2334 or http://www.aedpregnancyregistry.org/

Animal studies in multiple species of animals have revealed evidence of developmental toxicity. Topiramate has shown teratogenicity in mice, rats, and rabbits. In humans, clinical data from a pregnancy registry and several epidemiologic studies have shown infants exposed during the first trimester have an increased incidence of major congenital malformations compared with a reference group not taking antiepileptic drugs (AED). Infants exposed in utero have an increased risk for cleft lip and/or cleft palate (oral clefts) and for being small for gestational age (SGA). SGA has been observed at all doses and appears to be dose-dependent. The prevalence of SGA is greater in infants of women who received higher doses of topiramate during pregnancy. In addition, the prevalence of SGA in infants of women who continued topiramate use until later in pregnancy is higher compared to the prevalence in infants of women who stopped before the third trimester. This drug can cause metabolic acidosis. The effect of topiramate-induced metabolic acidosis has not been studied in pregnancy; however, metabolic acidosis in pregnancy (due to other causes) can cause decreased fetal growth, decreased fetal oxygenation, and fetal death, and may affect the ability of the fetus to tolerate labor. There are no controlled data in human pregnancy.

AU TGA pregnancy category D: Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D and X are being phased out.

References

  1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  2. Cerner Multum, Inc. "Australian Product Information." O 0
  3. "Product Information. Qudexy XR Sprinkle (topiramate)." Upsher-Smith Laboratories Inc (2017):
  4. "Product Information. Trokendi XR (topiramate)." Supernus Pharmaceuticals Inc (2017):
  5. "Product Information. Topiramate (topiramate)." Cipla USA Inc. (2017):

The following applies to the ingredients: Levothyroxine (found in Synthroid)

Professional Content

Use is considered acceptable

AU TGA pregnancy category: A
US FDA pregnancy category: Not Assigned

Risk Summary: No increased rates of major birth defects or miscarriages have been reported with use during pregnancy; untreated hypothyroidism during pregnancy is associated with risks to the mother and fetus

Comments:
-Thyroid replacement therapy should not be discontinued during pregnancy; hypothyroidism diagnosed during pregnancy should be promptly treated.
-Monitor TSH levels and adjust doses as needed.

Animal studies have not been conducted. There is a long history of using this drug in pregnant women and this experience has not shown increased rates of fetal malformations, miscarriages or other adverse maternal or fetal outcomes. Hypothyroidism during pregnancy is associated with a higher rate of complications, including spontaneous abortion, pre-eclampsia, stillbirth and premature delivery. Maternal hypothyroidism may have an adverse effect on fetal neurocognitive development. Pregnant women taking this drug should have their TSH measured during each trimester and dose adjusted as appropriate. Patients will generally return to their pre-pregnancy dose after delivery. There are no controlled data in human pregnancy.

AU TGA pregnancy category A: Drugs which have been taken by a large number of pregnant women and women of childbearing age without any proven increase in the frequency of malformations or other direct or indirect harmful effects on the fetus having been observed.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

References

  1. "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical PROD (2002):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. Pharmaceutical Society of Australia "APPGuide online. Australian prescription products guide online. http://www.appco.com.au/appguide/default.asp" (2006):
  4. Cerner Multum, Inc. "Australian Product Information." O 0

Drug and Breastfeeding Interactions

The following applies to the ingredients: Topiramate (found in Topamax)

Professional Content

Benefit should outweigh risk

Excreted into human milk: Yes

Comments:
-The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for this drug and any potential adverse effects on the breastfed infant from this drug or from the underlying maternal condition.
-If this drug is used during breastfeeding, monitor breastfed infant for diarrhea, drowsiness, adequate weight gain, and developmental milestones, especially younger, exclusively breastfed infants.
-Some authorities recommend avoiding breastfeeding during therapy with this drug.

Limited data in women with epilepsy have shown drug levels in milk similar to those in maternal plasma. The excretion of topiramate has not been evaluated in controlled studies.

References

  1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  2. Cerner Multum, Inc. "Australian Product Information." O 0
  3. United States National Library of Medicine "Toxnet. Toxicology Data Network. http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" (2013):
  4. "Product Information. Qudexy XR Sprinkle (topiramate)." Upsher-Smith Laboratories Inc (2017):
  5. "Product Information. Trokendi XR (topiramate)." Supernus Pharmaceuticals Inc (2017):
  6. "Product Information. Topiramate (topiramate)." Cipla USA Inc. (2017):

The following applies to the ingredients: Levothyroxine (found in Synthroid)

Professional Content

Use is considered acceptable

Excreted into human milk: Yes

Comments:
-Levothyroxine (T4) is a normal component of human milk; limited data on exogenous replacement doses during breastfeeding have not shown an adverse effect in nursing infants.
-Levothyroxine dose requirements may be increased in the postpartum period compared to prepregnancy requirements in patients with Hashimoto's thyroiditis.
-The presence of thyroid hormone in breast milk does not appear to interfere with neonatal thyroid screening.

References

  1. "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical PROD (2002):
  2. Jansson L, Ivarsson S, Larsson I, Ekman R "Tri-iodothyronine and thyroxine in human milk." Acta Paediatr Scand 72 (1983): 703-5
  3. Moller B, Bjorkhem I, Falk O, Lantto O, Lafsson A "Identification of thyroxine in human breast milk by gas chromatography-mass spectrometry." J Clin Endocrinol Metab 56 (1983): 30-4
  4. Mizuta H, Amino N, Ichihara K, et al. "Thyroid hormones in human milk and their influence on thyroid function of breast-fed babies." Pediatr Res 17 (1983): 468-71
  5. Hahn HB, Spiekerman AM, Otto R, Hossalla DE "Thyroid function tests in neonates fed human milk." Am J Dis Child 137 (1983): 220-2
  6. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  7. Pharmaceutical Society of Australia "APPGuide online. Australian prescription products guide online. http://www.appco.com.au/appguide/default.asp" (2006):
  8. Cerner Multum, Inc. "Australian Product Information." O 0
  9. United States National Library of Medicine "Toxnet. Toxicology Data Network. http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" (2013):

Therapeutic Duplication Warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

Switch to: Professional Interactions

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.

Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

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