Do not take this medicine with any of the following medications:

-alfuzosin
-certain medicines for cholesterol like lovastatin or simvastatin
-conivaptan
-dronedarone
-eletriptan
-eplerenone
-ergot alkaloids like dihydroergotamine or ergotamine
-flibanserin
-isavuconazonium
-ivabradine
-lomitapide
-lurasidone
-naloxegol
-pimozide
-ranolazine
-silodosin
-tolvaptan
-triazolam
-ubrogepant
This medicine may also interact with the following medications:

-certain medicines for seizures like carbamazepine, phenobarbital, phenytoin
-clopidogrel
-digoxin
-gemfibrozil
-midazolam
-rifampin
-St. Johns Wort

They need to know if you have any of these conditions:

-liver disease
-an unusual or allergic reaction to tucatinib, other medicines, foods, dyes or preservatives
-pregnant or trying to get pregnant
-breast-feeding

Visit your health care professional for regular checks on your progress. Tell your health care professional if your symptoms do not start to get better or if they get worse.
Do not become pregnant while taking this medicine or for 1 week after stopping it. Women should inform their health care professional if they wish to become pregnant or think they might be pregnant. Men should not father a child while taking this medicine and for 1 week after stopping it. There is potential for serious side effects to an unborn child. Talk to your health care professional for more information.
Do not breast-feed a child while taking this medicine or for 1 week after stopping it.
This medicine has caused ovarian failure in some women. This medicine may make it more difficult to get pregnant. Talk to your health care professional if you are concerned about your fertility.
This medicine has caused decreased sperm counts in some men. This may make it more difficult to father a child. Talk to your health care professional if you are concerned about your fertility.

Keep out of the reach of children.
Store between 20 and 25 degrees C (68 and 77 degrees F). Keep this medicine in the original container. Do not throw out the packet in the container. It keeps the medicine dry.