What is the interaction between grapefruit and lurasidone (Latuda) or quetiapine (Seroquel)?

From the Guidelines

Grapefruit should be avoided when taking lurasidone (Latuda) or quetiapine (Seroquel) as it can significantly increase blood levels of these medications, potentially leading to serious side effects. The interaction between grapefruit and these medications is due to the inhibition of the enzyme CYP3A4 in the intestines, which normally breaks down these antipsychotic medications 1. When this enzyme is blocked, more of the medication enters the bloodstream, effectively creating an unintended overdose.

Key Considerations

• The effect of grapefruit on CYP3A4 can last for up to 72 hours after consumption, making it essential to avoid grapefruit altogether, not just at the time of taking medication 1.
• The increased blood levels of lurasidone or quetiapine can intensify side effects such as drowsiness, dizziness, confusion, and in severe cases may lead to irregular heartbeat or other serious complications.
• If you're prescribed either lurasidone or quetiapine, it's best to completely eliminate grapefruit, grapefruit juice, and similar citrus fruits like Seville oranges and pomelos from your diet.
• Regular oranges, tangerines, and lemons do not have this interaction and are safe alternatives.

Clinical Implications

• Patients taking lurasidone or quetiapine should be advised to avoid grapefruit and grapefruit juice to minimize the risk of adverse interactions 1.
• Healthcare providers should consider the potential interaction between grapefruit and these medications when prescribing or monitoring treatment plans.
• The amount and type of juice being ingested, as well as specific information characterizing a given interaction, should be considered in evaluating the potential juice-drug interactions 1.

From the FDA Drug Label

Grapefruit and grapefruit juice should be avoided in patients taking lurasidone hydrochloride tablets, since these may inhibit CYP3A4 and alter lurasidone hydrochloride tablets concentrations [ see Drug Interactions (7.1)]. The interaction between grapefruit and lurasidone (Latuda) is that grapefruit and grapefruit juice should be avoided because they may inhibit CYP3A4 and alter lurasidone concentrations. There is no information about the interaction between grapefruit and quetiapine (Seroquel) in the provided drug label 2.

From the Research

Interaction between Grapefruit and Lurasidone or Quetiapine

• The interaction between grapefruit and lurasidone (Latuda) or quetiapine (Seroquel) is not directly mentioned in the provided studies.
• However, the studies suggest that grapefruit juice can increase the concentrations of many drugs in humans by suppressing the cytochrome P450 enzyme CYP3A4 in the small intestine wall 3, 4, 5, 6, 7.
• Lurasidone and quetiapine are both psychotropic drugs, and grapefruit juice has been shown to interact with many psychotropic drugs by increasing their bioavailability and potentially leading to toxic levels 5.
• The mechanism of interaction is complex and connected with the influence of grapefruit juice's active ingredients on prehepatic metabolism and enteric absorption pathways using p-glicoprotein (PGP) and organic anion transporting polypeptide (OATP) 5, 6, 7.
• It is recommended that patients refrain from drinking grapefruit juice when taking drugs that are extensively metabolized, unless a lack of interaction has already been demonstrated for the drug 3, 4, 6, 7.
• Patients taking psychotropics, including lurasidone and quetiapine, should be informed about the potential risk of interaction with grapefruit juice and advised to avoid its consumption 5, 7.