Studies examining the effects of grapefruit on PDE5 inhibitors like Filitra 20 and similar drugs (e.g., sildenafil) suggest that the interaction is significant. Research has shown that grapefruit juice can increase the plasma concentration of vardenafil, leading to a higher risk of side effects. In fact, the combination of grapefruit and certain medications is often advised against, with health professionals recommending that patients avoid consuming grapefruit when taking drugs metabolized by CYP3A4.
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