Skip to main content

Drug Interactions between erythromycin / sulfisoxazole and Quin-G

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

Edit list (add/remove drugs)

Interactions between your drugs

Major

quiNIDine erythromycin

Applies to: Quin-G (quinidine) and erythromycin / sulfisoxazole

GENERALLY AVOID: Coadministration of quinidine with some macrolide antibiotics (e.g., clarithromycin, erythromycin, troleandomycin) may increase the risk of ventricular arrhythmias including torsade de pointes and sudden death due to additive effects on the QT interval. In addition, the clearance of quinidine may be reduced. Data are available for erythromycin. In six healthy male volunteers, erythromycin 250 mg given orally four times a day reduced the median total clearance and peak plasma concentration (Cmax) of a single 200 mg oral dose of quinidine sulfate by 34% and 39%, respectively. The mechanism may involve enhanced absorption as well as reduced clearance of quinidine due to inhibition of both intestinal P-glycoprotein efflux transporter and hepatic/intestinal CYP450 3A4 isoenzyme by erythromycin. A case report describes a 74-year-old patient whose serum trough quinidine levels increased by 50% two days after starting erythromycin lactobionate 500 mg every 6 hours with ceftriaxone 1 gram daily. The patient later developed torsades de pointes arrhythmia when the erythromycin dosage was doubled and metronidazole was added. A 25% reduction in the quinidine dose was required, and erythromycin and metronidazole were subsequently replaced with doxycycline and ciprofloxacin. Another case of torsades de pointes, followed by cardiac arrest, was reported in a 95-year-old patient receiving quinidine and erythromycin orally.

MANAGEMENT: The use of quinidine in combination with macrolide antibiotics should be avoided. Patients treated with these agents should be advised to seek medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitations, irregular heartbeat, shortness of breath, or syncope.

References

  1. "Product Information. Eryc (erythromycin)." Parke-Davis PROD
  2. Spinler SA, Cheng JWM, Kindwall KE, Charland SL "Possible inhibition of hepatic metabolism of quinidine by erythromycin." Clin Pharmacol Ther 57 (1995): 89-94
  3. Lin JC, Quasny HA "QT prolongation and development of torsades de pointes with the concomitant administration of oral erythromycin base and quinidine." Pharmacotherapy 17 (1997): 626-30
  4. Damkier P, Hansen LL, Brosen K "Effect of fluvoxamine on the pharmacokinetics of quinidine." Eur J Clin Pharmacol 55 (1999): 451-6
View all 4 references

Switch to consumer interaction data

Drug and food interactions

Moderate

quiNIDine food

Applies to: Quin-G (quinidine)

GENERALLY AVOID: In a small, randomized, crossover study, the administration of quinidine with grapefruit juice (compared to water) to healthy volunteers significantly prolonged the time to reach peak plasma quinidine concentrations and decreased the plasma concentrations of its major metabolite, 3-hydroxyquinidine. These changes were associated pharmacodynamically with both a delay and a reduction in the maximal effect on QTc interval. The proposed mechanism is delay of gastric emptying as well as inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall induced by certain compounds present in grapefruits.

MANAGEMENT: Given the drug's narrow therapeutic index, patients receiving quinidine therapy should avoid the consumption of grapefruits and grapefruit juice to prevent any undue fluctuations in plasma drug levels.

References

  1. Ace LN, Jaffe JM, Kunka RL "Effect of food and an antacid on quinidine bioavailability." Biopharm Drug Dispos 4 (1983): 183-90
  2. Min DI, Ku YM, Geraets DR, Lee HC "Effect of grapefruit juice on the pharmacokinetics and pharmacodynamics of quinidine in healthy volunteers." J Clin Pharmacol 36 (1996): 469-76
  3. Ha HR, Chen J, Leuenberger PM, Freiburghaus AU, Follah F "In vitro inhibition of midazolam and quinidine metabolism by flavonoids." Eur J Clin Pharmacol 48 (1995): 367-71
  4. Bailey DG, Dresser GR, Kreeft JH, Munoz C, Freeman DJ, Bend JR "Grapefruit-felodipine interaction: Effect of unprocessed fruit and probable active ingredients." Clin Pharmacol Ther 68 (2000): 468-77
View all 4 references

Switch to consumer interaction data

Moderate

erythromycin food

Applies to: erythromycin / sulfisoxazole

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

Minor

erythromycin food

Applies to: erythromycin / sulfisoxazole

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.

See also

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.

Medical Disclaimer