Melatonin - Codeine Phosphate Interaction

Interaction Details

Codeine Phosphate is classified as belonging to the following category: Cns Depressants

Theoretically, taking melatonin might increase the sedative effects of CNS depressants.
Melatonin has sedative effects. Theoretically, concomitant use of melatonin with alcohol, benzodiazepines, or other sedative drugs might cause additive sedation.

Interaction Rating

Likelihood of Occurrence

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

Pharmacist Analysis

Melatonin can interact with drugs that cause sedation or CNS depression, such as benzodiazepines, opioids, and alcohol, leading to additive effects (i.e., additive sedation and drowsiness effects).

This interaction can increase drowsiness and impair cognitive and motor functions, which may be unsafe for activities that require alertness and concentration, such as driving or operating heavy machinery.

However, if you are using melatonin solely for sleep at night, the interaction is generally not of significant concern.

Nevertheless, it is advisable to consult with a healthcare provider before taking melatonin with other medications, especially those that affect the central nervous system.

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

Codeine Phosphate is classified as belonging to the following category: Seizure Threshold Lowering Drugs

Theoretically, taking melatonin with drugs that lower the seizure threshold might increase the risk of seizure activity.
Some clinical evidence suggests that melatonin may increase the frequency of seizures in certain patients, particularly children with neurological disabilities.

Interaction Rating

Likelihood of Occurrence

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

• Sheldon SH. Pro-convulsant effects of oral melatonin in neurologically disabled children. Lancet 1998;351:1254.
• Stewart LS. Endogenous melatonin and epileptogenesis: facts and hypothesis. Int J Neurosci 2001;107:77-85..

Interaction Details

Codeine Phosphate is classified as belonging to the following category: Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP2D6.
Laboratory research suggests that certain lots of melatonin inhibit CYP2D6. Theoretically, combined administration of melatonin with certain drugs metabolized by the CYP2D6 enzyme 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

Likelihood of Occurrence

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

Pharmacist Analysis

There is some evidence to suggest that melatonin may inhibit the activity of the CYP2D6 enzyme (a type of metabolizing enzyme).

CYP2D6 is responsible for metabolizing many drugs, including some antidepressants, antipsychotics, and beta blockers. When this enzyme is inhibited, it can lead to increased levels of these drugs in the body, which can cause side effects or toxicity.

Studies are conflicting as some have shown that melatonin can inhibit CYP2D6 while others have found no significant effect of melatonin on CYP2D6 activity.

Overall, the potential interaction between melatonin and drugs metabolized by CYP2D6 is still unclear and may depend on factors such as the dose of melatonin, the specific drug being metabolized, and individual differences in metabolism.

It is always recommended to consult with a healthcare provider before taking any new supplements or medications, especially if you are taking other medications or have underlying health conditions.

References

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

Codeine Phosphate Overview

• Codeine is used to relieve mild to moderate pain. It is also used, usually in combination with other medications, to reduce coughing. Codeine will help relieve symptoms but will not treat the cause of symptoms or speed recovery. Codeine belongs to a class of medications called opiate (narcotic) analgesics and to a class of medications called antitussives. When codeine is used to treat pain, it works by changing the way the brain and nervous system respond to pain. When codeine is used to reduce coughing, it works by decreasing the activity in the part of the brain that causes coughing.

• Codeine is also available in combination with acetaminophen (Capital and Codeine, Tylenol with Codeine), aspirin, carisoprodol, and promethazine and as an ingredient in many cough and cold medications. This monograph only includes information about the use of codeine. If you are taking a codeine combination product, be sure to read information about all the ingredients in the product you are taking and ask your doctor or pharmacist for more information.

Melatonin - More Interactions

Melatonin interacts with 1404 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.