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Drug Interactions between aminoglutethimide and Biltricide

This report displays the potential drug interactions for the following 2 drugs:

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Interactions between your drugs

Moderate

praziquantel aminoglutethimide

Applies to: Biltricide (praziquantel) and aminoglutethimide

GENERALLY AVOID: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations of praziquantel, which is a substrate of the isoenzyme. In a crossover study with a 2-week washout period, plasma praziquantel concentrations were undetectable in 7 out of 10 subjects who ingested a single 40 mg/kg dose of praziquantel following pretreatment with the potent CYP450 3A4 inducer, rifampin, given at 600 mg daily for 5 days. When the same dose of praziquantel was administered two weeks after discontinuation of rifampin, the mean praziquantel peak plasma concentration (Cmax) and systemic exposure (AUC) were only 35% and 23% lower, respectively, than when praziquantel was given alone. The oral bioavailability of praziquantel has also been shown to decrease significantly in patients treated with carbamazepine or phenytoin, both of which are known potent CYP450 3A4 inducers. In one study, maximum plasma praziquantel concentrations in epileptic patients receiving stable carbamazepine (n=10) and phenytoin (n=10) therapy were 8% and 24%, respectively, of those observed in control subjects following administration of a single 25 mg oral dose of praziquantel. The extent to which other, less potent CYP450 3A4 inducers may interact with praziquantel is unknown.

MANAGEMENT: Concomitant use of praziquantel with CYP450 3A4 inducers should generally be avoided, since therapeutically effective blood levels of praziquantel may not be achieved. Alternative agents for schistosomiasis should be considered whenever possible in patients receiving treatment with a CYP450 3A4 inducer. Otherwise, clinical response to praziquantel should be closely monitored.

References

  1. Bittencourt PR, Gracia CM, Martins R, et al. "Phenytoin and carbamazepine decrease oral bioavailability of praziquantel." Neurology 42 (1992): 492-6
  2. "Product Information. Biltricide (praziquantel)." Bayer PROD (2001):
  3. Ridtitid W, Wongnawa M, Mahatthanatrakul W, Punyo J, Sunbhanich M "Rifampin markedly decreases plasma concentrations of praziquantel in healthy volunteers." Clin Pharmacol Ther 72 (2002): 505-13
  4. Cerner Multum, Inc. "Australian Product Information." O 0
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Drug and food interactions

Moderate

praziquantel food

Applies to: Biltricide (praziquantel)

ADJUST DOSING INTERVAL: Administration with food increases the oral bioavailability of praziquantel. The mechanism has not been described. In nine healthy volunteers, administration of praziquantel (1800 mg single oral dose) following a high-fat meal increased the mean praziquantel peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) by 243% and 180%, respectively, compared to administration under fasting conditions. Administration with a high-carbohydrate meal increased these values by 515% and 271%, respectively, compared to fasting. Overall, the relative bioavailability was increased by a factor of 2.72 and 3.98 with the high-fat and high-carbohydrate meals, respectively. The time to reach peak concentration (Tmax) and elimination half-life (T1/2) were not significantly altered.

Coadministration with grapefruit juice may increase the oral bioavailability of praziquantel. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall induced by certain compounds present in grapefruit. In 18 healthy volunteers, administration of praziquantel (1800 mg single oral dose) with 250 mL of commercially squeezed grapefruit juice resulted in increases in the mean praziquantel Cmax and AUC of 63% and 90%, respectively, compared to administration with water. The Tmax and T1/2 were not significantly altered. The pharmacokinetics of praziquantel were subject to a high degree of interpatient variability with and without grapefruit juice.

MANAGEMENT: To ensure maximal oral absorption, praziquantel should be administered with meals. Administration with grapefruit juice may further increase pharmacologic effects of praziquantel, including adverse effects such dizziness, abdominal discomfort, and nausea.

References

  1. Castro N, Jung H, Medina R, Gonzalez-Esquivel D, Lopez M, Sotelo J "Interaction between grapefruit juice and praziquantel in humans." Antimicrob Agents Chemother 46 (2002): 1614-6
  2. Castro N, Medina R, Sotelo J, Jung H "Bioavailability of praziquantel increases with concomitant administration of food." Antimicrob Agents Chemother 44 (2000): 2903-4

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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.


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Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor 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.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.