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7 Interactions found for:

Synthroid and trazodone
Interactions Summary
  • 2 Major
  • 2 Moderate
  • 3 Minor
  • Synthroid
  • trazodone

Drug Interactions

Minor
Synthroid + Trazodone

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

A small series of cases has suggested that exogenous thyroid hormones may potentiate the antidepressant actions of trazodone. The mechanism of the interaction has not been completely elucidated.

References

  1. Browne JL, Rice JL, Evans DL, Prange AJ "Triiodothyronine augmentation of the antidepressant effect of the nontricyclic antidepressant trazodone." J Nerv Ment Dis 178 (1990): 598-9

Drug and Food Interactions

Moderate
Synthroid + Food

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

ADJUST DOSING INTERVAL: Consumption of certain foods as well as the timing of meals relative to dosing may affect the oral absorption of T4 thyroid hormone (i.e., levothyroxine). T4 oral absorption is increased by fasting and decreased by foods such as soybean flour (e.g., infant formula), cotton seed meal, walnuts, dietary fiber, calcium, and calcium fortified juices. Grapefruit or grapefruit products may delay the absorption of T4 thyroid hormone and reduce its bioavailability. The mechanism of this interaction is not fully understood.

MANAGEMENT: Some manufacturers recommend administering oral T4 as a single daily dose, on an empty stomach, one-half to one hour before breakfast. In general, oral preparations containing T4 thyroid hormone should be administered on a consistent schedule with regard to time of day and relation to meals to avoid large fluctuations in serum levels. Foods that may affect T4 absorption should be avoided within several hours of dosing if possible. Consult local guidelines for the administration of T4 in patients receiving enteral feeding.

References

  1. "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical PROD (2002):
  2. "Product Information. Armour Thyroid (thyroid desiccated)." Forest Pharmaceuticals (2022):
  3. Wohlt PD, Zheng L, Gunderson S, Balzar SA, Johnson BD, Fish JT "Recommendations for the use of medications with continuous enteral nutrition." Am J Health Syst Pharm 66 (2009): 1438-67

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

ADJUST DOSING INTERVAL: Concurrent administration of calcium-containing products may decrease the oral bioavailability of levothyroxine by one-third in some patients. Pharmacologic effects of levothyroxine may be reduced. The exact mechanism of interaction is unknown but may involve nonspecific adsorption of levothyroxine to calcium at acidic pH levels, resulting in an insoluble complex that is poorly absorbed from the gastrointestinal tract. In one study, 20 patients with hypothyroidism who were taking a stable long-term regimen of levothyroxine demonstrated modest but significant decreases in mean free and total thyroxine (T4) levels as well as a corresponding increase in mean thyrotropin (thyroid-stimulating hormone, or TSH) level following the addition of calcium carbonate (1200 mg/day of elemental calcium) for 3 months. Four patients had serum TSH levels that were higher than the normal range. Both T4 and TSH levels returned to near-baseline 2 months after discontinuation of calcium, which further supported the likelihood of an interaction. In addition, there have been case reports suggesting decreased efficacy of levothyroxine during calcium coadministration. It is not known whether this interaction occurs with other thyroid hormone preparations.

MANAGEMENT: Some experts recommend separating the times of administration of levothyroxine and calcium-containing preparations by at least 4 hours. Monitoring of serum TSH levels is recommended. Patients with gastrointestinal or malabsorption disorders may be at a greater risk of developing clinical or subclinical hypothyroidism due to this interaction.

References

  1. Schneyer CR "Calcium carbonate and reduction of levothyroxine efficacy." JAMA 279 (1998): 750
  2. Singh N, Singh PN, Hershman JM "Effect of calcium carbonate on the absorption of levothyroxine." JAMA 283 (2000): 2822-5
  3. Csako G, McGriff NJ, Rotman-Pikielny P, Sarlis NJ, Pucino F "Exaggerated levothyroxine malabsorption due to calcium carbonate supplementation in gastrointestinal disorders." Ann Pharmacother 35 (2001): 1578-83
  4. Neafsey PJ "Levothyroxine and calcium interaction: timing is everything." Home Healthc Nurse 22 (2004): 338-9

Moderate
Trazodone + Food

The following applies to the ingredients: Trazodone

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

References

  1. Warrington SJ, Ankier SI, Turner P "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology 15 (1986): 31-7
  2. Gilman AG, eds., Nies AS, Rall TW, Taylor P "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc. (1990):
  3. "Product Information. Fycompa (perampanel)." Eisai Inc (2012):
  4. "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc (2015):

Drug and Pregnancy Interactions

The following applies to the ingredients: Trazodone

This drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.
-Some experts recommend: Use with caution; use should be avoided during the first trimester of pregnancy.

US FDA pregnancy category: C

Comment: When this drug is used until delivery, newborns should be monitored for the occurrence of withdrawal symptoms.

Animal studies have revealed evidence of increased fetal resorption and congenital anomalies in adolescents. Other animal models have failed to reveal evidence of adverse effects on embryofetal development, parturition, or postnatal development when given at therapeutic doses. There are no controlled data in human pregnancy.

US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

References

  1. "Product Information. Desyrel (trazodone)." Bristol-Myers Squibb PROD (2001):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

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

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: Trazodone

A decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.
-Some experts recommend: Caution is recommended.

Excreted into human milk: Yes

Comments:
-The effects in the nursing infant are unknown.
-The American Academy of Pediatrics considers this agent a drug for which the effect on nursing infants is unknown but may be of concern.

References

  1. "Product Information. Desyrel (trazodone)." Bristol-Myers Squibb PROD (2001):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. Briggs GG, Freeman RK. "Drugs in Pregnancy and Lactation." Philadelphia, PA: Wolters Kluwer Health (2015):

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

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: Consumer 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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