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 taken with ritonavir, your body may not process rifabutin properly.
What might happen:
When rifabutin is taken with ritonavir, your blood levels of rifabutin may increase and cause harmful effects.
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. If you experience a persistent sore throat or fever, contact your doctor. The dose of your medicines may need adjusting.Your healthcare professionals 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 March, 2015.
4.Phansalkar S, Desai AA, Bell D, Yoshida E, Doole J, Czochanski M, Middleton B, Bates DW. High-priority drug-drug interactions for use in electronic health records. J Am Med Inform Assoc 2012 Sep-Oct; 19(5):735-43.
5.Mycobutin (rifabutin) US prescribing information. Pfizer Inc. July, 2015.