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6 Interactions found for:

Flexeril and metformin
Interactions Summary
  • 1 Major
  • 1 Moderate
  • 4 Minor
  • Flexeril
  • metformin

Drug Interactions

No drug interactions were found for selected drugs: Flexeril, metformin.

This does not necessarily mean no interactions exist. Always consult your healthcare provider.

Drug and Food Interactions

Major
Metformin + Food

The following applies to the ingredients: Metformin

GENERALLY AVOID: Alcohol can potentiate the effect of metformin on lactate metabolism and increase the risk of lactic acidosis. In addition, alcohol may cause hypoglycemia or hyperglycemia in patients with diabetes. Although hypoglycemia rarely occurs during treatment with metformin alone, the risk may increase with acute consumption of alcohol. Even modest amounts can lower blood sugar significantly, especially when the alcohol is ingested on an empty stomach or following exercise. The mechanism involves inhibition of both gluconeogenesis as well as the counter-regulatory response to hypoglycemia. Episodes of hypoglycemia may last for 8 to 12 hours after ethanol ingestion. By contrast, chronic alcohol abuse can cause impaired glucose tolerance and hyperglycemia. Moderate alcohol consumption generally does not affect blood glucose levels in patients with well controlled diabetes.

Food may have varying effects on the absorption of metformin from immediate-release versus extended-release formulations. When a single 850 mg dose of immediate-release metformin was administered with food, mean peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 40% and 25%, respectively, and time to peak plasma concentration (Tmax) increased by 35 minutes compared to administration under fasting conditions. By contrast, administration of extended-release metformin with food increased AUC by 50% without affecting Cmax or Tmax, and both high- and low-fat meals had the same effect. These data may not be applicable to formulations that contain metformin with other oral antidiabetic agents.

MANAGEMENT: Metformin should be taken with meals, and excessive alcohol intake should be avoided during treatment. Diabetes patients in general should avoid consuming alcohol if their blood glucose is not well controlled, or if they have hypertriglyceridemia, neuropathy, or pancreatitis. Alcohol should not be consumed on an empty stomach or following exercise, as it may increase the risk of hypoglycemia. Patients should contact their physician immediately if they experience potential signs and symptoms of lactic acidosis such as malaise, myalgia, respiratory distress, increasing somnolence, and nonspecific abdominal distress (especially after stabilization of metformin therapy, when gastrointestinal symptoms are uncommon). With more marked acidosis, there may also be associated hypothermia, hypotension, and resistant bradyarrhythmias. Metformin should be withdrawn promptly if lactic acidosis is suspected. Serum electrolytes, ketones, blood glucose, blood pH, lactate levels, and blood metformin levels may be useful in establishing a diagnosis. Lactic acidosis should be suspected in any diabetic patient with metabolic acidosis lacking evidence of ketoacidosis (ketonuria and ketonemia).

References

  1. "Product Information. Glucophage (metformin)." Bristol-Myers Squibb PROD (2001):
  2. "Position Statement: evidence-based nutrition principles and recommendations for the treatment and prevention of diabetes related complications. American Diabetes Association." Diabetes Care 25(Suppl 1) (2002): S50-S60

Moderate
Flexeril + Food

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

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: Cyclobenzaprine (found in Flexeril)

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):

The following applies to the ingredients: Metformin

Benefit should outweigh risk

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

Risk Summary: Data are not sufficient to inform a drug-associated risk for major birth defects or miscarriage; published studies have not reported an increased risk. There are risks to the mother and fetus associated with poorly controlled diabetes in pregnancy.

Comments:
-Maternal glucose levels should be well controlled prior to conception and throughout pregnancy to avoid maternal and fetal diabetes-associated risks.
-Premenopausal women should understand the potential for unintended pregnancy with use of this drug as ovulation may occur in some anovulatory women.

Animal studies do not indicate harmful effects with respect to pregnancy, embryo or fetal development, birth or postnatal development. Poorly-controlled diabetes in pregnancy increases the maternal risk for diabetic ketoacidosis, pre-eclampsia, spontaneous abortions, preterm delivery, stillbirth and delivery complications. Poorly controlled maternal diabetes increases the fetal risk for major birth defects, stillbirth, and macrosomia related morbidity. Published evidence suggests this drug has a good safety profile in women with no increased long-term effects in offspring up to 18 months; however, much of the evidence is from observational, small, and/or nonrandomized studies, and therefore data must be interpreted cautiously.

Many experts continue to recommend insulin as the drug of choice for type 1, type 2, and gestational diabetes when diet alone is unsuccessful in controlling blood sugars. The estimated background risk for major birth defects in women with pre-gestational diabetes mellitus with an HbA1C greater than 7 is 6% to 10% and for women with a HbA1C greater than 10, this risk has been reported to be as high as 20% to 25%. In the US, the estimated risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. The estimated risk of miscarriage for pregnant women with diabetes is unknown. There are no adequate and well-controlled studies in pregnant women.

AU TGA pregnancy category C: Drugs which, owing to their pharmacological effects, have caused or may be suspected of causing, harmful effects on the human fetus or neonate without causing malformations. These effects may be reversible. Accompanying texts should be consulted for further details.

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. Glucophage (metformin)." Bristol-Myers Squibb 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. Fortamet (metformin)." Physicians Total Care (2014):
  5. "Product Information. Glumetza (metformin)." Biovail Pharmaceuticals Canada (2014):
  6. "Product Information. Riomet (metformin)." Ranbaxy Pharmaceuticals (2014):
  7. Lindsay RS, Loeken MR "Metformin use in pregnancy: promises and uncertainties" Diabetologia 60 (2017): 1612-9
  8. Kelley KW, Carroll DG, Meyer A "A review of current treatment strategies for gestational diabetes mellitus." Drugs Context 4 (2015): epub

Drug and Breastfeeding Interactions

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

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):

The following applies to the ingredients: Metformin

Benefit should outweigh risk

Excreted into human milk: Yes

Comments:
-Available data have not reported adverse effects in breastfed infants, however, this data is limited.
-Due to this limited data, product manufacturers recommend a decision should be made to discontinue nursing or discontinue the drug, considering the importance of the drug to the mother.
-Published data suggest this drug is compatible with breastfeeding; they recommend caution when nursing a newborn or premature infant, and those with renal impairment.

Drug levels are expected to be 0.5% (range 0.11% to 1%) of the mother's weight-adjusted dosage and milk/plasma ratio range between 0.13 and 1. Since milk levels are expected to be relatively constant, timing of breastfeeding with drug administration is expected to be of little benefit. One large prospective study found no adverse effects in breastfed infants. Low detectable serum levels were found in some breastfed infants.

References

  1. "Product Information. Glucophage (metformin)." Bristol-Myers Squibb PROD (2001):
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  3. Feig DS, Briggs GG, Koren G "Oral antidiabetic agents in pregnancy and lactation: a paradigm shift?" Ann Pharmacother (2007): 1174-80
  4. Cerner Multum, Inc. "Australian Product Information." O 0
  5. United States National Library of Medicine "Toxnet. Toxicology Data Network. http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" (2013):
  6. "Product Information. Fortamet (metformin)." Physicians Total Care (2014):
  7. "Product Information. Glumetza (metformin)." Biovail Pharmaceuticals Canada (2014):
  8. "Product Information. Riomet (metformin)." Ranbaxy Pharmaceuticals (2014):
  9. Kelley KW, Carroll DG, Meyer A "A review of current treatment strategies for gestational diabetes mellitus." Drugs Context 4 (2015): epub

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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