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7 Interactions found for:

Lantus and levothyroxine
Interactions Summary
  • 0 Major
  • 3 Moderate
  • 4 Minor
  • Lantus
  • levothyroxine

Drug Interactions

Moderate
Levothyroxine + Lantus

The following applies to the ingredients: Levothyroxine and Insulin Glargine (found in Lantus)

Levothyroxine may interfere with blood glucose control and reduce the effectiveness of insulin glargine and other diabetic medications. Monitor your blood sugar levels closely. You may need a dose adjustment of your diabetic medications during and after treatment with levothyroxine. 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 Food Interactions

Moderate
Levothyroxine + Food

The following applies to the ingredients: Levothyroxine

The timing of meals relative to your oral levothyroxine dose can affect the 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 and/or delayed by foods such as soybean flour, cotton seed meal, walnuts, dietary fiber, calcium, calcium fortified juices and grapefruit or grapefruit juice. 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.

The following applies to the ingredients: Levothyroxine

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.

Moderate
Lantus + Food

The following applies to the ingredients: Insulin Glargine (found in Lantus)

Alcohol may affect blood glucose levels in patients with diabetes. Both hypoglycemia (low blood sugar) and hyperglycemia (high blood sugar) may occur, depending on how much and how often you drink. You should avoid using alcohol if your diabetes is not well controlled or if you have high triglycerides, neuropathy (nerve damage), or pancreatitis. Moderate alcohol consumption generally does not affect blood glucose levels if your diabetes is under control. However, it may be best to limit alcohol intake to one drink daily for women and two drinks daily for men (1 drink = 5 oz wine, 12 oz beer, or 1.5 oz distilled spirits) in conjunction with your normal meal plan. Avoid drinking alcohol on an empty stomach or following exercise, as it may increase the risk of hypoglycemia. 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: Levothyroxine

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

The following applies to the ingredients: Insulin Glargine (found in Lantus)

Professional Content

Use during pregnancy only if the potential benefit justifies the potential risk to the fetus

AU TGA pregnancy category: B3
US FDA pregnancy category: Not assigned

Risk Summary: Published studies of insulin glargine use during pregnancy have not reported a clear association with adverse developmental outcomes; there are risks to the mother and fetus associated with poorly controlled diabetes in pregnancy.

Comments:
-Patients with diabetes or a history of gestational diabetes should maintain good metabolic control before conception and during pregnancy. Insulin requirements may decrease during the first trimester; generally increase during the second and third trimesters, and rapidly decline after delivery. Careful monitoring of glucose control is essential.

For rats and rabbits, dosed at 50 and 10 times the human subcutaneous dose during organogenesis, respectively, the effects of insulin glargine did not differ greatly from those observed with regular human insulin. In rabbits, 5 fetuses from 2 high-dosed litters exhibited dilation of the cerebral ventricles. Fertility and early embryonic development appeared normal. In published human pregnancy reports, no specific adverse effects of insulin glargine on pregnancy and no specific malformations nor fetal or neonatal toxicity has been reported. These studies are not definitive in ruling out the absence of risk due to methodological limitations. The estimated background risk of major birth defects in women with pregestational diabetes with an HbA1c greater than 7 is 6% to 10%; in women with a HbA1c greater than 10, it has been reported to be as high as 20% to 25%. There are no controlled data in human pregnancy.

Clinical Considerations:
-Poorly controlled diabetes during pregnancy increases the maternal risk for diabetic ketoacidosis, preeclampsia, spontaneous abortions, preterm delivery, and delivery complications.
-Poorly controlled diabetes during pregnancy increases the fetal risk for major birth defects, stillbirth, and macrosomia related morbidity.

AU TGA pregnancy category B3: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have shown evidence of an increased occurrence of fetal damage, the significance of which is considered uncertain in humans.

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. Lantus (insulin glargine)." Aventis Pharmaceuticals PROD (2001):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. Cerner Multum, Inc. "Australian Product Information." O 0
  4. "Product Information. Toujeo SoloStar (insulin glargine)." sanofi-aventis (2015):
  5. "Product Information. Basaglar (insulin glargine)." Eli Lilly Canada Inc (2018):

Drug and Breastfeeding Interactions

The following applies to the ingredients: Levothyroxine

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):

The following applies to the ingredients: Insulin Glargine (found in Lantus)

Professional Content

Use is considered acceptable; caution is recommended.

Excreted into human milk: Yes

Comments: Women who are breastfeeding may require adjustments in insulin dose and diet.

Exogenous insulins, including the newer biosynthetic insulins (i.e. aspart, detemir, glargine, glulisine, lispro) appear to be excreted into breast milk. Insulin is a protein that is inactivated if taken by mouth. If absorbed, it would be destroyed in the digestive tract of the infant.

Lactation onset occurs later in women with type 1 diabetes, and there is an even greater delay in those with poor glucose control. However, once established lactation persists. Insulin requirements are generally lower in women who breastfeed, most likely due to glucose being used for milk production.

References

  1. "Product Information. Lantus (insulin glargine)." Aventis Pharmaceuticals PROD (2001):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. Cerner Multum, Inc. "Australian Product Information." O 0
  4. United States National Library of Medicine "Toxnet. Toxicology Data Network. http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" (2013):
  5. "Product Information. Toujeo SoloStar (insulin glargine)." sanofi-aventis (2015):
  6. "Product Information. Basaglar (insulin glargine)." Eli Lilly Canada Inc (2018):

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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