Drug Interactions between fluconazole and venlafaxine

Alcohol can increase the nervous system side effects of venlafaxine such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with venlafaxine. Do not use more than the recommended dose of venlafaxine, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. Talk to your doctor or pharmacist if you have any questions or concerns.

Adult and pediatric patients with depression and other psychiatric disorders may experience worsening of their symptoms and may have the emergence of suicidal thoughts and behavior. Patients should be monitored appropriately and observed closely for worsening of their symptoms, suicidality or changes in their behavior, especially during the first few months of treatment, and at times of dose changes. Discontinuing the medication should be considered if symptoms are persistently worse, or abrupt in onset. It may be prudent to refrain from dispensing large quantities of medication to these patients.

Adult and pediatric patients with depression and other psychiatric disorders may experience worsening of their symptoms and may have the emergence of suicidal thoughts and behavior. Patients should be monitored appropriately and observed closely for worsening of their symptoms, suicidality or changes in their behavior, especially during the first few months of treatment, and at times of dose changes. Discontinuing the medication should be considered if symptoms are persistently worse, or abrupt in onset. It may be prudent to refrain from dispensing large quantities of medication to these patients.

The use of fluconazole has been rarely associated with hepatotoxicity. Reversible idiosyncratic hepatitis, cholestasis and fatal fulminant hepatic failure have been reported, the latter occurring primarily in patients with serious underlying medical conditions and taking multiple concomitant medications. Liver function tests should be performed periodically in patients with preexisting hepatic abnormalities, particularly during prolonged therapy. Treatment should be withdrawn if persistent elevations or worsening of liver enzyme levels occur.

Venlafaxine is metabolized by the liver, and both the parent drug and metabolites are excreted by the kidney. Patients with renal and/or liver disease may be at greater risk for adverse effects from venlafaxine due to decreased drug clearance. Therapy with venlafaxine should be administered cautiously in patients with impaired renal and/or hepatic function. A reduction in the total daily dosage is recommended. The manufacturer suggests a 50% reduction in patients with moderate hepatic impairment (possibly more in patients with cirrhosis), a 25% reduction in patients with mild to moderate renal impairment, and a 50% reduction in patients undergoing hemodialysis (to be administered after dialysis treatment).

The clearance of SNRI antidepressants is decreased in subjects with renal impairment. SNRIs should be used with caution in this group of patients and a dose adjustment is recommended in those with moderate and severe renal impairment. The use of SNRIs is not recommended in patients with end-stage renal disease.

Venlafaxine is metabolized by the liver, and both the parent drug and metabolites are excreted by the kidney. Patients with renal and/or liver disease may be at greater risk for adverse effects from venlafaxine due to decreased drug clearance. Therapy with venlafaxine should be administered cautiously in patients with impaired renal and/or hepatic function. A reduction in the total daily dosage is recommended. The manufacturer suggests a 50% reduction in patients with moderate hepatic impairment (possibly more in patients with cirrhosis), a 25% reduction in patients with mild to moderate renal impairment, and a 50% reduction in patients undergoing hemodialysis (to be administered after dialysis treatment).

Some azole antifungals have been associated with prolongation of the QT interval on the ECG. Rare cases of QT prolongation and torsade de pointes have been reported during postmarketing experience; such reports usually involved seriously ill patients with multiple confounding risk factors, such as structural heart disease, electrolyte abnormalities, and concomitant medications. These drugs should be administered with caution to patients with potentially proarrhythmic conditions, such as congenital/acquired QT prolongation, cardiomyopathy (especially when heart failure is present), sinus bradycardia, and existing symptomatic arrhythmias. Concomitant use with other medications that have potential to increase the risk of cardiotoxicity should be avoided.

Therapy with SNRI antidepressants can cause activation of mania and hypomania and should be used with caution in patients with personal or family history of mania, hypomania, bipolar disorder, and other mood disorders.

All antidepressants may occasionally cause mania or hypomania, particularly in patients with bipolar disorder. Therapy with antidepressants should be administered cautiously in patients with a history of mania/hypomania.

Treatment with SNRI antidepressants can cause hyponatremia. Caution should be used when treating patients with hyponatremia or at greater risk of hyponatremia such as the elderly, patients taking diuretics or who are volume depleted.

SNRI antidepressants cause pupillary dilation that may trigger an angle closure attack in patients with anatomically narrow angle without iridectomy.

Fluconazole is substantially removed by hemodialysis. Plasma levels of fluconazole has been shown to reduce by 50% following 3 hours of dialysis. Fluconazole should be administered after hemodialysis.

Selective serotonin and norepinephrine reuptake inhibitor antidepressants (SNRIs) have been associated with sustained increases in blood pressure. Therapy with SNRI antidepressants should be administered cautiously in patients with preexisting hypertension. Blood pressure should be assessed prior to initiating treatment and monitored regularly. The dose should be reduced or discontinued if necessary.

Treatment with SNRI antidepressants can cause hyponatremia. Caution should be used when treating patients with hyponatremia or at greater risk of hyponatremia such as the elderly, patients taking diuretics or who are volume depleted.

Therapy with SNRI antidepressants can cause activation of mania and hypomania and should be used with caution in patients with personal or family history of mania, hypomania, bipolar disorder, and other mood disorders.

All antidepressants may occasionally cause mania or hypomania, particularly in patients with bipolar disorder. Therapy with antidepressants should be administered cautiously in patients with a history of mania/hypomania.

Fluconazole is primarily eliminated by the kidney. Patients with renal impairment may be at greater risk for adverse effects from fluconazole due to decreased drug clearance. Dosage adjustments are recommended for patients with moderate to severe renal impairment (CrCl <= 50 mL/min) receiving multiple doses of the drug.

SNRI antidepressants may trigger seizures and should be administered with caution in patients with a seizure disorder.

SNRI antidepressants have a noradrenergic effect and can affect urethral resistance. Caution should be used in patients with a history of dysuria, prostatic hypertrophy, prostatitis, and other lower urinary tract obstructive disorders.

SNRI antidepressants have a noradrenergic effect and can affect urethral resistance. Caution should be used in patients with a history of dysuria, prostatic hypertrophy, prostatitis, and other lower urinary tract obstructive disorders.

The use of venlafaxine may occasionally cause significant, dose-dependent weight loss, which may be undesirable in patients suffering from anorexia, malnutrition or excessive weight loss. The loss of at least 5% of body weight occurred in 6% to 7% of treated patients in premarketing studies, compared to 1% to 2% for placebo. Anorexia may occur in approximately 10% of patients. Weight change should be monitored during therapy if venlafaxine is used in malnourished or underweight patients.

The use of venlafaxine may occasionally cause significant, dose-dependent weight loss, which may be undesirable in patients suffering from anorexia, malnutrition or excessive weight loss. The loss of at least 5% of body weight occurred in 6% to 7% of treated patients in premarketing studies, compared to 1% to 2% for placebo. Anorexia may occur in approximately 10% of patients. Weight change should be monitored during therapy if venlafaxine is used in malnourished or underweight patients.

The use of venlafaxine may occasionally cause significant, dose-dependent weight loss, which may be undesirable in patients suffering from anorexia, malnutrition or excessive weight loss. The loss of at least 5% of body weight occurred in 6% to 7% of treated patients in premarketing studies, compared to 1% to 2% for placebo. Anorexia may occur in approximately 10% of patients. Weight change should be monitored during therapy if venlafaxine is used in malnourished or underweight patients.