Drug Interactions between clarithromycin and Doc-Q-Lax

GENERALLY AVOID: Chronic use of stimulant laxatives may decrease the absorption of fat-soluble vitamins (A, D, E, and K) and minerals such as calcium, potentially leading to deficiencies. This effect is due to accelerated intestinal transit time, which reduces nutrient absorption.

MANAGEMENT: To minimize this risk, limit the use of stimulant laxatives to short-term or occasional use.

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.

The use of stimulant laxatives is contraindicated in patients with or who may have acute surgical abdomen or appendicitis. These patients may be candidates for emergency surgery. Stimulant laxatives should also not be administered to patients with abdominal pain, particularly if the cause has not been determined.

The use of stimulant laxatives is contraindicated in patients with anal or rectal fissures. These preparations may cause irritation, burning sensation, and proctitis.

Clostridioides difficile-associated diarrhea (CDAD), formerly pseudomembranous colitis, has been reported with almost all antibacterial drugs and may range from mild diarrhea to fatal colitis. The most common culprits include clindamycin and lincomycin. Antibacterial therapy alters the normal flora of the colon, leading to overgrowth of C difficile, whose toxins A and B contribute to CDAD development. Morbidity and mortality are increased with hypertoxin-producing strains of C difficile; these infections can be resistant to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea after antibacterial use. Since CDAD has been reported to occur more than 2 months after antibacterial use, careful medical history is necessary. Therapy with broad-spectrum antibacterials and other agents with significant antibacterial activity should be administered cautiously in patients with history of gastrointestinal disease, particularly colitis; pseudomembranous colitis (generally characterized by severe, persistent diarrhea and severe abdominal cramps, and sometimes associated with the passage of blood and mucus), if it occurs, may be more severe in these patients and may be associated with flares in underlying disease activity. Antibacterial drugs not directed against C difficile may need to be stopped if CDAD is suspected or confirmed. Appropriate fluid and electrolyte management, protein supplementation, antibacterial treatment of C difficile, and surgical evaluation should be started as clinically indicated.

The use of laxatives is contraindicated in patients with intestinal obstruction disorders. Patients with intestinal obstruction disorders may need their underlying condition treated to correct the constipation. Some laxatives require reduction in the colon to their active form to be effective which may be a problem in patients with intestinal obstruction.

The use of laxatives is contraindicated in patients with intestinal obstruction disorders. Patients with intestinal obstruction disorders may need their underlying condition treated to correct the constipation. Some laxatives require reduction in the colon to their active form to be effective which may be a problem in patients with intestinal obstruction.

The use of laxatives is contraindicated in patients with inflammatory bowel disease. Patients with inflammatory bowel disease may experience colonic perforation with use of stimulant laxatives.

The use of laxatives is contraindicated in patients with inflammatory bowel disease. Patients with inflammatory bowel disease may experience colonic perforation with use of stimulant laxatives.

Macrolides have been associated with prolongation of the QT interval and infrequent cases of arrhythmia. Clarithromycin and erythromycin should be avoided in: patients with known prolongation of the QT interval, ventricular cardiac arrhythmia, including torsades de pointes; patients with proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, or receiving other drugs that prolong the QT interval.

Macrolides have been associated with prolongation of the QT interval and infrequent cases of arrhythmia. Clarithromycin and erythromycin should be avoided in: patients with known prolongation of the QT interval, ventricular cardiac arrhythmia, including torsades de pointes; patients with proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, or receiving other drugs that prolong the QT interval.

Hepatic dysfunction, including increased liver enzymes, and hepatocellular and/or cholestatic hepatitis, with or without jaundice, has been reported in patients receiving clarithromycin. The hepatic dysfunction may be severe but in most cases is reversible. Fatal outcomes have also been reported and in general have been associated with serious underlying diseases and/or concomitant medications. Caution and monitoring is advised if using this drug in patients with hepatic impairment. Treatment must be discontinued immediately if signs and symptoms of hepatitis occur (e.g., anorexia, jaundice, dark urine, pruritus, or tender abdomen). The use of clarithromycin and combination medications containing this antibiotic are contraindicated in patients with a history of cholestatic jaundice or hepatic impairment associated with the prior use of clarithromycin.

Macrolides have been associated with prolongation of the QT interval and infrequent cases of arrhythmia. Clarithromycin and erythromycin should be avoided in: patients with known prolongation of the QT interval, ventricular cardiac arrhythmia, including torsades de pointes; patients with proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, or receiving other drugs that prolong the QT interval.

The use of macrolide antibiotics has been reported to exacerbate symptoms of myasthenia gravis and trigger new onset of symptoms of myasthenic syndrome. Therapy with these agents should be administered cautiously in patients with a history of myasthenia gravis.

Clarithromycin is primarily eliminated by the kidney and liver. A decreased dosage or prolonged dosing intervals are recommended in patients with severe renal impairment (CrCl < 30 mL/min). Dosage adjustments are usually not necessary in patients with mild to moderate renal impairment, although drug accumulation could occur in the presence of concomitant liver disease. Monitoring is advised.