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7 Interactions found for:

Neurontin and Flexeril
Interactions Summary
  • 2 Major
  • 3 Moderate
  • 2 Minor
  • Neurontin
  • Flexeril

Drug Interactions

Moderate
Flexeril + Neurontin

The following applies to the ingredients: Cyclobenzaprine (found in Flexeril) and Gabapentin (found in Neurontin)

Using cyclobenzaprine together with gabapentin may increase side effects such as dizziness, drowsiness, confusion, and difficulty concentrating. Some people, especially the elderly, may also experience impairment in thinking, judgment, and motor coordination. You should avoid or limit the use of alcohol while being treated with these medications. Also avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medications affect you. Talk to your doctor if you have any questions or concerns. 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
Flexeril + Food

The following applies to the ingredients: Cyclobenzaprine (found in Flexeril)

Alcohol can increase the nervous system side effects of cyclobenzaprine such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with cyclobenzaprine. Do not use more than the recommended dose of cyclobenzaprine, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. Talk to your doctor or pharmacist if you have any questions or concerns.

Moderate
Neurontin + Food

The following applies to the ingredients: Gabapentin (found in Neurontin)

Alcohol can increase the nervous system side effects of gabapentin such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with gabapentin. Do not use more than the recommended dose of gabapentin, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. Talk to your doctor or pharmacist if you have any questions or concerns.

Drug and Pregnancy Interactions

The following applies to the ingredients: Gabapentin (found in Neurontin)

Professional Content

Benefits should clearly outweigh risks

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

Risk Summary: There are no data on the developmental risks associated with use of this drug in pregnant women; in animal studies, developmental toxicity was observed at doses estimated to be similar or lower than those used clinically.

Comments:
-The risk of having a child with a congenital defect as a result of antiepileptic medication is far outweighed by the dangers to the mother and fetus of uncontrolled epilepsy; folic acid supplementation (5 mg) should be started 4 weeks prior to and continued for 12 weeks after conception.
-Women of childbearing potential should receive counseling on the risk of fetal abnormalities with use of antiepileptic drugs (AEDs) during pregnancy; AEDs should generally be continued during pregnancy utilizing monotherapy at the lowest effective dose as this has been shown to minimize risks of fetal abnormalities compared to combination AED therapy.
-A pregnancy exposure registry is available.

Animal studies have revealed evidence of developmental toxicity (increased fetal skeletal and visceral abnormalities, and increased embryofetal mortality) when administered at doses similar to, or lower than expected clinical doses. In rats, an increased incidence of hydroureter and/or hydronephrosis have been observed in offspring at all doses, the lowest dose being similar to the maximum recommended human dose on a mg/m2 basis. This drug crosses the human placenta. From the limited amount of data in human pregnancy, it is not possible to inform an associated increased risk of congenital malformations because epilepsy itself and the presence of concomitant antiepileptic medicinal products have their own risks. There are no controlled data in human pregnancy.

To provide information regarding the effects of in utero exposure to this drug, pregnant patients should be encouraged to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry. This can be done by calling the toll-free number 1-888-233-2334 and must be done by patients themselves. Information on the registry can also be found at the website http://www.aedpregnancyregistry.org/.

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. Neurontin (gabapentin)." Parke-Davis 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. Horizant (gabapentin)." GlaxoSmithKline (2021):
  5. "Product Information. Gralise (gabapentin)." Depomed Inc (2021):

The following applies to the ingredients: Cyclobenzaprine (found in Flexeril)

Professional Content

This drug should be used during pregnancy only if clearly needed.

US FDA pregnancy category: B

Embryofetal development in rats and rabbits given approximately 3 and 15 times, respectively, the maximum recommended human dose (MRHD) was not adversely effected. Dams receiving this drug at doses 3 times or more the MRHD during pregnancy and lactation, had pups with decreased body weight and survival. There are no adequate and controlled studies in pregnant women.

US FDA pregnancy category B: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.
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References

  1. "Product Information. Flexeril (cyclobenzaprine)." Merck & Co., Inc PROD (2001):
  2. "Product Information. Amrix (cyclobenzaprine)." A-S Medication Solutions (2016):

Drug and Breastfeeding Interactions

The following applies to the ingredients: Gabapentin (found in Neurontin)

Professional Content

Benefits should clearly outweigh risks

Excreted into human milk: Yes

Comments:
-Breastfed infants should be monitored for drowsiness, adequate weight gain, and developmental milestones, especially when used in combination with other anticonvulsant or psychotropic drugs and in younger, exclusively breastfed infants.
-Some authorities suggest discontinuing nursing or discontinuing use of this drug while breastfeeding due to the potential for serious adverse reactions in the breastfed infant.

With maternal doses up to 2.1 g/day, estimated doses for fully breastfed infants are 0.2 to 1.3 mg/kg/day (equivalent to 1.3 to 3.8% of the maternal weight-adjusted dose). An expert panel has deemed this drug is an acceptable choice for refractory restless leg syndrome during lactation. Until more data becomes available, the developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for this drug and any potential adverse effects on the breastfed infant from this drug or from the underlying maternal condition.

References

  1. "Product Information. Neurontin (gabapentin)." Parke-Davis 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. Horizant (gabapentin)." GlaxoSmithKline (2021):
  6. "Product Information. Gralise (gabapentin)." Depomed Inc (2021):

The following applies to the ingredients: Cyclobenzaprine (found in Flexeril)

Professional Content

Caution is recommended.

Excreted into human milk: Unknown
Excreted into animal milk: Yes

The effects in the nursing infant are unknown.

This drug has been shown to be excreted in rat milk and achieve concentrations in the milk which are 50% of those in the rat maternal plasma. As this drug is closely related to the tricyclic antidepressants, some of which are known to be excreted in human milk, use caution especially when other drugs that cause sedation are used simultaneously.

References

  1. Hucker HB, Stauffer SC, Balletto AJ, White SD, Zacchei AG, Arison BH "Physiological disposition and metabolism of cyclobenzaprine in the rat, dog, rhesus monkey, and man." Drug Metab Dispos 6 (1978): 659-72
  2. "Product Information. Flexeril (cyclobenzaprine)." Merck & Co., Inc PROD (2001):
  3. "Product Information. Amrix (cyclobenzaprine)." A-S Medication Solutions (2016):

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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