Doing so could increase side effects or decrease the effectiveness of the medication.

Doing so may decrease the effectiveness of the drug.

Which herb can decrease the effectiveness of some chemotherapy drugs?

Fact: Continued smoking decreases the effectiveness of cancer treatment and may make side effects worse.

Nicotine use can increase pain and decrease the effectiveness of medicines.

There is evidence that it may decrease the effectiveness of methylphenidate treatment.

This medication may decrease the effectiveness of birth control pills.

Doing so could decrease the effectiveness of this medication.

Removing the tablets in advance could decrease the drug's effectiveness.

Taking barley along with medicine you take by mouth can decrease the effectiveness of your medication.