5 Interactions found for:
Drug Interactions
No drug interactions were found for selected drugs: Celebrex, levothyroxine.
This does not necessarily mean no interactions exist. Always consult your healthcare provider.
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.
Drug and Pregnancy Interactions
Major
Celebrex
+ Pregnancy
The following applies to the ingredients: Celecoxib (found in Celebrex)
Professional Content
Contraindicated last trimester of pregnancy
Between 20- and 30-weeks' gestation: Limit dose and duration of use
AU TGA pregnancy category: B3
US FDA pregnancy category: Not assigned
Risk Summary: Use of nonsteroidal anti-inflammatory drugs (NSAIDs) in pregnant women can cause premature closure of the fetal ductus arteriosus and fetal renal dysfunction leading to oligohydramnios and, in some cases, neonatal renal impairment. Embryofetal risks of NSAID use in women in the first or second trimesters of pregnancy are inconclusive. Embryo-fetal deaths and an increase in diaphragmatic hernias were observed in rats administered this drug during the period of organogenesis.
Comments:
-NSAID use in pregnancy prior to 20 weeks gestation should be based on a benefit-risk assessment; some authorities recommend avoiding NSAIDs throughout pregnancy whenever possible.
-If NSAID use is necessary between 20- and 30-weeks' gestation, limit use to the lowest effective dose for the shortest duration possible; ultrasound monitoring of amniotic fluid should be considered if NSAID use extends beyond 48 hours; if oligohydramnios occurs, discontinue NSAID and treat appropriately.
-NSAID use is not recommended in women attempting to conceive as it may impair female fertility.
In animal studies, embryo-fetal deaths and an increase in diaphragmatic hernias were observed in rats administered this drug daily during the period of organogenesis at oral doses approximately 6 times the maximum recommended human dose (MRHD). In addition, structural abnormalities (e.g., septal defects, ribs fused, sternebrae fused and sternebrae misshapen) were observed in rabbits given daily oral doses during the period of organogenesis at approximately 2 times the MRHD. In animal studies, administration of prostaglandin synthesis inhibitors has been shown to increase pre- and postimplantation loss. In published animal studies, prostaglandin synthesis inhibitors have been reported to impair kidney development when administered at clinically relevant doses. There are no controlled data in human pregnancy. Published reports of NSAID use at about 30 weeks gestation and later in pregnancy have shown NSAIDs may cause premature closure of the fetal ductus arteriosus. Through 2017, the US FDA has received 35 reports of low amniotic fluid levels or kidney problems in mothers who took NSAIDs while pregnant. Five newborns died; 2 had kidney failure and confirmed low amniotic fluid, 3 had kidney failure without confirmed low amniotic fluid. The low amniotic fluid started as early as 20 weeks of pregnancy. There were 11 reports of low amniotic fluid levels during pregnancy and the fluid volume returned to normal after the NSAID was stopped. The medical literature has reported low amniotic fluid levels with use of NSAIDs for varying amounts of time, ranging from 48 hours to multiple weeks. Complications of prolonged oligohydramnios may include limb contractures and delayed lung maturation. In some postmarketing cases of impaired neonatal renal function, invasive procedures such as exchange transfusion or dialysis were required. In other cases, the condition was reversible within 3 to 6 days of stopping the NSAID and in these cases reappeared when the same NSAID was restarted.
NSAIDs may delay or prevent rupture of ovarian follicles which has been associated with reversible infertility in some women. The withdrawal of NSAID therapy should be considered in women with difficulties conceiving or who are undergoing investigation of infertility.
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
- "Product Information. Celebrex (celecoxib)." Searle PROD (2001):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Cerner Multum, Inc. "Australian Product Information." O 0
- US Food and Drug Administration "FDA recommends avoiding use of NSAIDs in pregnancy at 20 weeks or later because they can result in low amniotic fluid. https://www.fda.gov/media/142967/download" (2020):
Minor
Levothyroxine
+ Pregnancy
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
- "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical PROD (2002):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Pharmaceutical Society of Australia "APPGuide online. Australian prescription products guide online. http://www.appco.com.au/appguide/default.asp" (2006):
- Cerner Multum, Inc. "Australian Product Information." O 0
Drug and Breastfeeding Interactions
Major
Celebrex
+ Breastfeeding
The following applies to the ingredients: Celecoxib (found in Celebrex)
Professional Content
Benefit should outweigh risk
Excreted into human milk: Yes
Comments:
-Low levels of this drug are excreted in breastmilk and are not expected to cause adverse effects in breastfed infants.
-Some authorities advise women to discontinue nursing or to discontinue the drug, considering the expected benefit of the drug to the mother because of the potential for adverse reaction in nursing infants.
Limited data has shown this drug is excreted into human milk in low levels. Data from 3 published reports estimate the average daily infant dose to be 10 to 40 mcg/kg/day, which is less than 1% of the weight-based therapeutic dose for a 2-year-old. In 2 breastfed infants (17 and 22 months of age) whose mothers took this drug 200 mg orally twice daily for many weeks, blood samples taken 4 hours after a maternal dose were undetectable (less than 10 mcg/L). No infant side effects were observed in these infants.
References
- "Product Information. Celebrex (celecoxib)." Searle PROD (2001):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Cerner Multum, Inc. "Australian Product Information." O 0
- United States National Library of Medicine "Toxnet. Toxicology Data Network. http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" (2013):
Minor
Levothyroxine
+ Breastfeeding
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
- "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical PROD (2002):
- Jansson L, Ivarsson S, Larsson I, Ekman R "Tri-iodothyronine and thyroxine in human milk." Acta Paediatr Scand 72 (1983): 703-5
- 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
- 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
- Hahn HB, Spiekerman AM, Otto R, Hossalla DE "Thyroid function tests in neonates fed human milk." Am J Dis Child 137 (1983): 220-2
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Pharmaceutical Society of Australia "APPGuide online. Australian prescription products guide online. http://www.appco.com.au/appguide/default.asp" (2006):
- Cerner Multum, Inc. "Australian Product Information." O 0
- 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 | |
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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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