Drug Interactions between posaconazole and tretinoin
This report displays the potential drug interactions for the following 2 drugs:
- posaconazole
- tretinoin
Interactions between your drugs
tretinoin posaconazole
Applies to: tretinoin and posaconazole
Consumer information for this interaction is not currently available.
MONITOR CLOSELY: Coadministration with azole antifungal agents may increase the plasma concentrations and toxicities of tretinoin. The proposed mechanism is inhibition of CYP450 2C9 and/or 3A4, two of the isoenzymes responsible for the metabolic clearance of tretinoin. All azole antifungal agents can inhibit CYP450 3A4, with itraconazole and ketoconazole considered particularly potent inhibitors. Fluconazole and voriconazole also inhibit CYP450 2C9, which may increase the likelihood of a significant interaction with tretinoin compared to agents that inhibit just CYP450 3A4. There have been isolated reports of pseudotumor cerebri, hypercalcemia, and acute renal failure in patients receiving tretinoin with concomitant azole antifungal therapy, primarily fluconazole or voriconazole. The conditions resolved following interruption of tretinoin therapy and/or discontinuation of the azole antifungal agent. As tretinoin is thought to undergo autoinduction of its own metabolism, CYP450 inhibitors have been investigated for use to boost plasma tretinoin concentrations and to overcome treatment resistance that often occurs with continued tretinoin therapy. In a study of two patients with acute promyelocytic leukemia, tretinoin systemic exposure (AUC) was found to be reduced significantly from baseline after one week of treatment. Following two daily doses of fluconazole administered 1 hour before tretinoin, the AUC of tretinoin increased by about 2- to 4-fold compared to day eight of tretinoin treatment alone, but similar to AUCs reported at baseline. In 13 patients who had received tretinoin daily for 4 consecutive weeks, administration of ketoconazole (400 to 1200 mg oral dose) 1 hour before the tretinoin dose on day 29 led to a 72% increase in tretinoin mean plasma AUC. Likewise, in 6 patients with lung cancer, a single 400 mg dose of ketoconazole (but not a 200 mg dose) one hour before tretinoin on day 29 increased tretinoin AUC by 115% compared to day 28 when tretinoin was given alone. No effect was observed when ketoconazole was given on day 2 relative to tretinoin alone on day one. By contrast, one study showed that prolonged ketoconazole administration (400 mg initially, then 200 mg daily for 14 days) in patients receiving tretinoin (45 mg/m2 twice daily for 14 days) had no effect on tretinoin auto-induction, but was associated with more vomiting.
MANAGEMENT: Caution is advised when tretinoin is prescribed in combination with azole antifungal agents such as fluconazole, itraconazole, ketoconazole, and voriconazole. Patients should be closely monitored and advised to seek medical attention immediately if they develop early symptoms of pseudotumour cerebri such as headache, nausea, vomiting, visual disturbances, photosensitivity, and tinnitus.
Drug and food interactions
posaconazole food
Applies to: posaconazole
Food significantly increases the absorption of posaconazole from the tablet or suspension formulations. The manufacturer recommends that you take the tablet with food and the oral suspension during or immediately (within 20 minutes) after a full meal. If you cannot eat a full meal, you should take the oral suspension with a liquid nutritional supplement like Ensure or an acidic carbonated beverage like ginger ale. Do not take these medications on an empty stomach, as it may lead to inadequate blood levels and reduced effectiveness. Ask your doctor before using alcohol together with posaconazole from delayed release suspension formulations as this may cause an increase in side effects. Talk to your doctor or pharmacist if you have any questions on how to use the medication properly.
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
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. |
Further information
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