There are multiple interactions reported between these two agents.

Interaction Details

Cyclophosphamide is classified as belonging to the following category: Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP2C19. Also, other CYP2C19 substrates might decrease the metabolism of melatonin, increasing melatonin levels.
Melatonin is metabolized in the liver primarily by the CYP2C19 and CYP1A2 enzymes. Theoretically, combined administration of melatonin with certain drugs metabolized by the CYP2C19 enzyme may reduce the metabolism of these drugs, resulting in increased serum levels. Conversely, some drugs metabolized by CYP2C19 may inhibit the metabolism of melatonin, resulting in increased serum levels of melatonin. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Interaction Rating

Moderate

Likelihood of Occurrence

Probable

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.

References

  • Yeleswaram, K., Vachharajani, N., and Santone, K. Involvement of cytochrome P-450 isozymes in melatonin metabolism and clinical implications. J Pineal Res 1999;26(3):190-191.
  • Faber, M. S., Jetter, A., and Fuhr, U. Assessment of CYP1A2 activity in clinical practice: why, how, and when? Basic Clin Pharmacol Toxicol. 2005;97(3):125-134.

Interaction Details

Cyclophosphamide is classified as belonging to the following category: Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP3A4.
Laboratory research shows that certain lots of melatonin inhibit CYP3A4. Theoretically, combined administration of melatonin with certain drugs metabolized by CYP3A4 may reduce the metabolism of these drugs, resulting in increased serum levels. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Interaction Rating

Minor

Likelihood of Occurrence

Possible

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

References

  • Foster BC, Cvijovic K, Boon HS, et al. Melatonin Interaction Resulting in Severe Sedation. J Pharm Pharm Sci 2015;18(2):124-31.

Interaction Details

Cyclophosphamide is classified as belonging to the following category: Immunosuppressants

Theoretically, melatonin might interfere with immunosuppressive therapy.
Melatonin can stimulate immune function. Theoretically, melatonin might interfere with immunosuppressive therapy.

Interaction Rating

Moderate

Likelihood of Occurrence

Possible

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists

References

  • Lissoni P, Barni S, Mandala M, et al. Decreased toxicity and increased efficacy of cancer chemotherapy using the pineal hormone melatonin in metastatic solic tumor patients with poor clinical status. Eur J Cancer 1999;35:1688-92.

Melatonin Overview

Melatonin Melatonin is a hormone that is produced naturally in the pineal gland. It is involved in several different bodily processes, such as the regulation of the body's sleep-wake cycle. Melatonin is available as a dietary supplement and is often used to help people with sleep disorders, such as insomnia, fall asleep more easily. There is some evidence to suggest that melatonin supplements may be helpful in reducing the time it takes to fall asleep and improving sleep quality, although the results of studies on this topic have been mixed. Studies show better support for some specific conditions, such as Delayed sleep phase syndrome (DSPS) and Non-24-hour sleep-wake disorder. Melatonin is generally considered to be safe when used in the short term, although it can cause side effects in some people, such as dizziness, headache, and nausea. While melatonin is a natural hormone, it is often synthesized for its use in dietary supplements.
See More Information Regarding Melatonin

Cyclophosphamide Overview

  • Cyclophosphamide is used alone or in combination with other medications to treat Hodgkin's lymphoma (Hodgkin's disease) and non-Hodgkin's lymphoma (types of cancer that begin in a type of white blood cells that normally fights infection); cutaneous T-cell lymphoma (CTCL, a group of cancers of the immune system that first appear as skin rashes); multiple myeloma (a type of cancer of the bone marrow); and certain types of leukemia (cancer of the white blood cells), including chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), acute myeloid leukemia (AML, ANLL), and acute lymphoblastic leukemia (ALL). It is also used to treat retinoblastoma (cancer in the eye), neuroblastoma (a cancer that begins in nerve cells and occurs mainly in children), ovarian cancer (cancer that begins in the female reproductive organs where eggs are formed), and breast cancer. Cyclophosphamide is also used to treat nephrotic syndrome (a disease that is caused by damage to the kidneys) in children whose disease has not improved, has gotten worse, or has come back after taking other medications or in children who experienced intolerable side effects with other medications. Cyclophosphamide is in a class of medications called alkylating agents. When cyclophosphamide is used to treat cancer, it works by slowing or stopping the growth of cancer cells in your body. When cyclophosphamide is used to treat nephrotic syndrome, it works by suppressing your body's immune system.

See More Information Regarding Cyclophosphamide

Melatonin - More Interactions

Melatonin interacts with 1423 drugs

Interaction Rating Key

These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.

Major The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur.
Moderate Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur.
Minor Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction.
Unknown No interactions have been reported or no interaction data is currently available.

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Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Drug descriptions are provided by MedlinePlus.

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In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!

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