Drug Interactions between Doc-Q-Lax and dronedarone

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of dronedarone. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. According to the product labeling, administration with grapefruit juice resulted in a 2.5-fold increase in dronedarone peak plasma concentration and a 3-fold increase in systemic exposure. Because dronedarone is associated with concentration-dependent prolongation of the QT interval, increased levels may potentiate the risk of ventricular arrhythmias such as torsade de pointes and sudden death.

ADJUST DOSING INTERVAL: Food increases the oral bioavailability of dronedarone. The mechanism of interaction is unknown. According to the product labeling, the absolute bioavailability of dronedarone increases from about 4% when administered in the fasted state to approximately 15% when administered with a high-fat meal.

MANAGEMENT: Patients treated with dronedarone should avoid consumption of grapefruit, grapefruit juice, and any supplement containing grapefruit extract. Dronedarone should be taken twice daily with the morning and evening meals.

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.

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.

Dronedarone has shown to double the risk of death in patients with symptomatic heart failure and recent decompensation requiring hospitalization or NYHA Class IV heart failure. It has also shown to double the risk of stroke and death and hospitalization due to heart failure in patients with atrial fibrillation. Other patients at risk include patients with second or third degree AV block, or sick sinus syndrome (except when used in conjunction with a functioning pacemaker), patients with bradycardia < 50 bpm, and patients with QT interval prolongation. The use of dronedarone is contraindicated in these patients.

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.

Dronedarone has shown to double the risk of death in patients with symptomatic heart failure and recent decompensation requiring hospitalization or NYHA Class IV heart failure. It has also shown to double the risk of stroke and death and hospitalization due to heart failure in patients with atrial fibrillation. Other patients at risk include patients with second or third degree AV block, or sick sinus syndrome (except when used in conjunction with a functioning pacemaker), patients with bradycardia < 50 bpm, and patients with QT interval prolongation. The use of dronedarone is contraindicated in these patients.

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.

Dronedarone is extensively metabolized by the liver. There is little clinical experience with moderate hepatic impairment and none in patients with severe hepatic impairment. No dosage adjustment is recommended for patients with moderate hepatic impairment, however its use is contraindicated in patients with severe hepatic impairment. Additionally hepatocellular liver injury, including acute liver failure has been reported in patients using dronedarone in the postmarketing setting. Patients should be advised to report immediately any symptoms suggesting hepatic injury, such as anorexia, nausea, vomiting, fever, malaise, fatigue, right upper quadrant pain, jaundice, dark urine or itching.

Dronedarone has shown to double the risk of death in patients with symptomatic heart failure and recent decompensation requiring hospitalization or NYHA Class IV heart failure. It has also shown to double the risk of stroke and death and hospitalization due to heart failure in patients with atrial fibrillation. Other patients at risk include patients with second or third degree AV block, or sick sinus syndrome (except when used in conjunction with a functioning pacemaker), patients with bradycardia < 50 bpm, and patients with QT interval prolongation. The use of dronedarone is contraindicated in these patients.