Drug Interaction Report
3 potential interactions and/or warnings found for the following 2 drugs:
- Biaxin XL (clarithromycin)
- Sulfatrim Pediatric (sulfamethoxazole / trimethoprim)
Interactions between your drugs
clarithromycin sulfamethoxazole
Applies to: Biaxin XL (clarithromycin), Sulfatrim Pediatric (sulfamethoxazole / trimethoprim)
Limited data suggest that sulfamethoxazole-trimethoprim (SMX-TMP) may rarely prolong the QT interval of the electrocardiogram. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. There have been isolated reports of QT prolongation and ventricular arrhythmias occurring in patients treated with SMX-TMP intravenously. However, a causal relationship has not been established, and the risk of clinically significant QT prolongation is unlikely at recommended dosages of SMX-TMP. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). In addition, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s). Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.
References
- Wiener I, Rubin D, Martinez E, et al. (1981) "QT prolongation and paroxysmal ventricular tachycardia occurring during fever following trimethoprim-sulfamethoxazole administration." Mt Sinai J Med, 48, p. 53-5
- Crouch MA, Limon L, Cassano AT (2003) "Clinical relevance and management of drug-related QT interval prolongation." Pharmacotherapy, 23, p. 881-908
- Lopez JA, Harold JG, Rosenthal MC, Oseran DS, Schapira JN, Peter T (1987) "QT prolongation and torsades de pointes after administration of trimethoprin-sulfamethoxazole." Am J Cardiol, 59, p. 376-7
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- Canadian Pharmacists Association (2006) e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink
- Cerner Multum, Inc. "Australian Product Information."
- Darpo B (2001) "Spectrum of drugs prolonging QT interval and the incidence of torsades de pointes." Eur Heart J Suppl, 3(Suppl K), K70-80
Drug and food interactions
sulfamethoxazole food
Applies to: Sulfatrim Pediatric (sulfamethoxazole / trimethoprim)
MONITOR: Two cases have been reported in which patients on sulfamethoxazole-trimethoprim therapy, after consuming beer, reported flushing, heart palpitations, dyspnea, headache, and nausea (disulfiram - alcohol type reactions). First-generation sulfonylureas have been reported to cause facial flushing when administered with alcohol by inhibiting acetaldehyde dehydrogenase and subsequently causing acetaldehyde accumulation. Since sulfamethoxazole is chemically related to first-generation sulfonylureas, a disulfiram-like reaction with products containing sulfamethoxazole is theoretically possible. However, pharmacokinetic/pharmacodynamic data are lacking and in addition, the two reported cases cannot be clearly attributed to the concomitant use of sulfamethoxazole-trimethoprim and alcohol.
MANAGEMENT: Patients should be alerted to the potential for this interaction and although the risk for this interaction is minimal, caution is recommended while taking sulfamethoxazole-trimethoprim concomitantly with alcohol.
References
- Heelon MW, White M (1998) "Disulfiram-cotrimoxazole reaction." Pharmacotherapy, 18, p. 869-70
- Mergenhagen KA, Wattengel BA, Skelly MK, Clark CM, Russo TA (2020) "Fact versus fiction: a review of the evidence behind alcohol and antibiotic interactions." Antimicrob Agents Chemother, 64, e02167-19
clarithromycin food
Applies to: Biaxin XL (clarithromycin)
Grapefruit juice may delay the gastrointestinal absorption of clarithromycin but does not appear to affect the overall extent of absorption or inhibit the metabolism of clarithromycin. The mechanism of interaction is unknown but may be related to competition for intestinal CYP450 3A4 and/or absorptive sites. In an open-label, randomized, crossover study consisting of 12 healthy subjects, coadministration with grapefruit juice increased the time to reach peak plasma concentration (Tmax) of both clarithromycin and 14-hydroxyclarithromycin (the active metabolite) by 80% and 104%, respectively, compared to water. Other pharmacokinetic parameters were not significantly altered. This interaction is unlikely to be of clinical significance.
References
- Cheng KL, Nafziger AN, Peloquin CA, Amsden GW (1998) "Effect of grapefruit juice on clarithromycin pharmacokinetics." Antimicrob Agents Chemother, 42, p. 927-9
Therapeutic duplication warnings
No duplication 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.
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
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. | |
No interaction information available. |
Learn more
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Check Interactions
To view an interaction report containing 4 (or more) medications, please sign in or create an account.
Save Interactions List
Sign in to your account to save this drug interaction list.