Drug, Food and Supplement — Interactions With Pazopanib

Proton pump inhibitors like omeprazole and pantoprazole are among the most widely prescribed medicines in India, and they present a real problem with pazopanib. They reduce stomach acid, and pazopanib needs acid to dissolve and absorb properly. The result is that significantly less pazopanib enters your bloodstream. ESMO guidance and the pazopanib prescribing information both flag this interaction. Ask your oncologist before continuing any acid medicine — there may be an alternative approach to managing acidity that interferes less with your treatment.

Yes, and this applies to grapefruit juice as well as fresh grapefruit. Grapefruit contains compounds that inhibit the same liver enzyme that processes pazopanib, which means pazopanib levels in your blood can rise unpredictably. There is no safe amount and no way to time around it. While you are on pazopanib, avoid grapefruit entirely. Other citrus fruits — oranges, lemons, limes — are generally fine, but if you are uncertain about a specific fruit, ask your team.

Ayurvedic preparations, homeopathic remedies, and herbal products can interact with pazopanib — including through the same CYP3A4 enzyme pathway. St. John's Wort is the best-documented example, but many herbal preparations contain compounds that affect liver enzymes in ways that have not been fully studied. Tell your oncologist what you are taking, including traditional preparations your family uses. The conversation will not result in judgment. It allows your team to assess the risk and adjust the plan if needed.

Pazopanib can affect how warfarin behaves, which means your blood-thinning level may change once you start treatment. Your INR will need to be monitored more frequently during the initial period. Do not adjust your warfarin dose yourself — let your care team manage any changes based on your results. This is a manageable interaction when it is anticipated and monitored, so make sure both your cardiologist and your oncology team know you are on both medicines.

Clarithromycin is a macrolide antibiotic that inhibits the CYP3A4 enzyme. When taken alongside pazopanib, it can raise pazopanib levels in your blood. Call your oncology team before starting any new antibiotic while on pazopanib. An alternative antibiotic may achieve the same result for your infection without the interaction risk. Your pharmacist can also check this quickly if you tell them you are on pazopanib.

Paracetamol at normal doses is not among the established major interactions with pazopanib. However, pazopanib already carries a risk of liver stress, and paracetamol in high or prolonged doses also affects the liver. Use the smallest amount that gives relief, do not exceed the dose on the packet, and avoid combining it with alcohol. For any new symptom including fever, call your oncology team first rather than managing it at home alone — fever during cancer treatment always needs to be assessed.

Some antifungal tablets — particularly ketoconazole and itraconazole — significantly inhibit the CYP3A4 enzyme and can raise pazopanib levels. Antifungal creams applied to the skin are absorbed in very small amounts and are generally a lower risk, but mention those to your team too. Before starting any oral antifungal tablet, contact your oncology team. An alternative may be available, or your pazopanib dose may need to be reviewed while you take the antifungal.

Do not stop any medicine suddenly without speaking to your care team first — for medicines such as anti-epileptics or blood thinners, sudden stopping can be dangerous. Call your oncologist or the clinic nurse today and describe what you have been taking. Your team will assess the interaction, check whether your pazopanib level or side effects have been affected, and advise you on whether to switch, adjust, or continue under closer monitoring. Raise it now rather than waiting for your next appointment.