Severe. These medicines may interact and cause very harmful effects and are usually not taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, your body may not process your pain medicine properly.
What might happen:
The blood levels of your pain medicine may increase. This may cause toxic effects such as drowsiness, slurred speech, or incoordination.
What you should do about this interaction:
Contact your healthcare professionals (e.g. doctor or pharmacist) as soon as possible about taking these two medicines together. They may already be aware of this drug interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Norvir (ritonavir) Australian prescribing information. Abbott Australasia Pty. Ltd. January 29, 2004.
2.Norvir (ritonavir) UK summary of product characteristics. Abbott Laboratories, Limited July 2, 2008.
3.Norvir (ritonavir) US prescribing information. Abbott Laboratories November, 2012.