Skip to main content

Drug Interactions between Erythrocin Lactobionate and Stendra

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Major

erythromycin avanafil

Applies to: Erythrocin Lactobionate (erythromycin) and Stendra (avanafil)

ADJUST DOSE: Coadministration with moderate inhibitors of CYP450 3A4 may increase the plasma concentrations of avanafil, which is primarily metabolized by the isoenzyme. In 15 healthy male volunteers, administration of a single 200 mg dose of avanafil following pretreatment with the moderate CYP450 3A4 inhibitor erythromycin (500 mg twice daily for 5 days) increased avanafil peak plasma concentration (Cmax) and systemic exposure (AUC) by approximately 2-fold and 3.6-fold, respectively, compared to administration of avanafil alone. Erythromycin also prolonged the half-life of avanafil to approximately 8 hours, from a normal of 5 hours.

MANAGEMENT: The dosage of avanafil should not exceed 50 mg once every 24 hours when used in combination with moderate CYP450 3A4 inhibitors.

References

  1. "Product Information. Stendra (avanafil)." Vivus Inc (2012):

Switch to consumer interaction data

Drug and food interactions

Moderate

erythromycin food

Applies to: Erythrocin Lactobionate (erythromycin)

ADJUST DOSING INTERVAL: Food may variably affect the bioavailability of different oral formulations and salt forms of erythromycin. The individual product package labeling should be consulted regarding the appropriate time of administration in relation to food ingestion. Grapefruit juice may increase the plasma concentrations of orally administered erythromycin. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. In an open-label, crossover study consisting of six healthy subjects, the coadministration with double-strength grapefruit juice increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of a single dose of erythromycin (400 mg) by 52% and 49%, respectively, compared to water. The half-life was not affected. The clinical significance of this potential interaction is unknown.

MANAGEMENT: In general, optimal serum levels are achieved when erythromycin is taken in the fasting state, one-half to two hours before meals. However, some erythromycin products may be taken without regard to meals.

References

  1. Welling PG, Huang H, Hewitt PF, Lyons LL "Bioavailability of erythromycin stearate: influence of food and fluid volume." J Pharm Sci 67 (1978): 764-6
  2. Welling PG, Elliott RL, Pitterle ME, et al. "Plasma levels following single and repeated doses of erythromycin estolate and erythromycin stearate." J Pharm Sci 68 (1979): 150-5
  3. Welling PG "Influence of food and diet on gastrointestinal drug absorption: a review." J Pharmacokinet Biopharm 5 (1977): 291-334
  4. Coyne TC, Shum S, Chun AH, Jeansonne L, Shirkey HC "Bioavailability of erythromycin ethylsuccinate in pediatric patients." J Clin Pharmacol 18 (1978): 194-202
  5. Malmborg AS "Effect of food on absorption of erythromycin. A study of two derivatives, the stearate and the base." J Antimicrob Chemother 5 (1979): 591-9
  6. Randinitis EJ, Sedman AJ, Welling PG, Kinkel AW "Effect of a high-fat meal on the bioavailability of a polymer-coated erythromycin particle tablet formulation." J Clin Pharmacol 29 (1989): 79-84
  7. Kanazawa S, Ohkubo T, Sugawara K "The effects of grapefruit juice on the pharmacokinetics of erythromycin." Eur J Clin Pharmacol 56 (2001): 799-803
View all 7 references

Switch to consumer interaction data

Moderate

avanafil food

Applies to: Stendra (avanafil)

GENERALLY AVOID: Additive hypotensive effects may occur when phosphodiesterase-5 (PDE5) inhibitors are used with alcohol, as both are mild systemic vasodilators. In clinical pharmacology studies, more subjects administered alcohol at a dose of 0.7 g/kg (equivalent to approximately 6 ounces of 80-proof vodka in an 80-kg male; consumed within 10 minutes in study subjects, providing blood alcohol levels of 0.08%) in combination with tadalafil 10 or 20 mg single doses had clinically significant decreases in blood pressure than with alcohol alone. There were reports of postural dizziness, and orthostatic hypotension was observed in some. When tadalafil 20 mg was administered with alcohol at a lower dose of 0.6 g/kg (equivalent to approximately 4 ounces of 80-proof vodka in an 80-kg male), orthostatic hypotension was not observed, dizziness occurred with similar frequency relative to alcohol alone, and the hypotensive effects of alcohol were not potentiated. Neither tadalafil nor alcohol affected the plasma concentrations of the other. Administration of avanafil 200 mg with alcohol at a dose of 0.5 g/kg (equivalent to approximately 3 ounces of 80-proof vodka in a 70-kg male; consumed within 15 minutes in study subjects, providing blood alcohol levels of 0.057%) resulted in additional maximum supine systolic/diastolic blood pressure decreases of 3.5/4.5 mm Hg and additional maximum pulse rate increase of 9.3 bpm compared to alcohol alone, but did not cause orthostatic hypotension or dizziness. The plasma concentrations of alcohol were not affected. Sildenafil 50 mg and vardenafil 20 mg reportedly did not potentiate the hypotensive effect of alcohol in healthy volunteers with mean maximum blood alcohol levels of 0.08% and in healthy volunteers administered alcohol at a dose of 0.5 g/kg, respectively. Alcohol and vardenafil plasma levels were not altered when dosed simultaneously.

GENERALLY AVOID: Coadministration with grapefruit juice is likely to increase the plasma concentrations of avanafil, which is primarily metabolized by CYP450 3A4. However, the interaction has not been studied. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit.

MANAGEMENT: Patients taking avanafil should avoid consuming large amounts of alcohol, which may increase the potential for orthostatic signs and symptoms including increase in heart rate, decrease in standing blood pressure, dizziness, and headache. It may also be appropriate to avoid consuming large amounts of grapefruit juice. Some authorities advise that grapefruit juice should be avoided within 24 hours prior to taking avanafil.

References

  1. "Product Information. Viagra (sildenafil)." Pfizer U.S. Pharmaceuticals PROD (2001):
  2. "Product Information. Levitra (vardenafil)." Bayer (2003):
  3. "Product Information. Cialis (tadalafil)." Lilly, Eli and Company (2003):
  4. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
  5. "Product Information. Stendra (avanafil)." Vivus Inc (2012):
View all 5 references

Switch to consumer interaction data

Minor

erythromycin food

Applies to: Erythrocin Lactobionate (erythromycin)

Ethanol, when combined with erythromycin, may delay absorption and therefore the clinical effects of the antibiotic. The mechanism appears to be due to slowed gastric emptying by ethanol. Data is available only for erythromycin ethylsuccinate. Patients should be advised to avoid ethanol while taking erythromycin salts.

References

  1. Morasso MI, Chavez J, Gai MN, Arancibia A "Influence of alcohol consumption on erythromycin ethylsuccinate kinetics." Int J Clin Pharmacol 28 (1990): 426-9

Switch to consumer interaction data

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.


Report options

Loading...
QR code containing a link to this page

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.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.