Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taken together, you may process your birth control pills differently. Your body may process fosamprenavir more quickly.
What might happen:
The effects of your birth control pills may decrease and cause breakthrough bleeding, spotting, or pregnancy.If you are taking atazanavir, you may notice an increase in acne and your cholesterol levels may increase.You may have an increased risk of developing a rash if you are taking tipranavir.Birth control pills could cause your fosamprenavir to not work as well against your HIV infection, if fosamprenavir is your only HIV medicine.
What you should do about this interaction:
Talk to your healthcare professional (e.g. doctor or pharmacist) as soon as possible about using a different form of birth control. Contact your doctor if you experience breakthrough bleeding, spotting, or pregnancy.Your healthcare professionals may already be aware of this 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.Reyataz (atazanavir sulfate) US prescribing information. Bristol-Myers Squibb Company August, 2013.
2.Lexiva (fosamprenavir calcium) US prescribing information. GlaxoSmithKline February, 2013.
3.Aptivus (tipranavir) US prescribing information. Boehringer Ingelheim Pharmaceuticals, Inc. February, 2012.
4.Prezista (darunavir) US prescribing information. Tibotec Inc. November, 2013.
5.Kaletra (lopinavir/ritonavir tablets) US prescribing information. Abbott Laboratories January, 2013.
6.Viracept (nelfinavir mesylate) US prescribing information. Agouron Pharmaceuticals, Inc. May, 2013.
7.Norvir (ritonavir) US prescribing information. Abbott Laboratories November, 2012.
8.Fortovase (saquinavir) US prescribing information. Roche Laboratories, Inc. December, 2004.
9.Invirase (saquinavir mesylate) US prescribing information. Roche Laboratories, Inc. February, 2012.
10.Nor-Q-D (norethindrone) US prescribing information. WatsonPharma March, 2005.
11.Ouellet D, Hsu A, Qian J, Locke CS, Eason CJ, Cavanaugh JH, Leonard JM, Granneman GR. Effect of ritonavir on the pharmacokinetics of ethinyl oestradiol in healthy female volunteers. Br J Clin Pharmacol 1998 Aug; 46(2):111-6.
12.Frohlich M, Burhenne J, Martin-Facklam M, Weiss J, von Wolff M, Strowitzki T, Walter-Sack I, Haefeli WE. Oral contraception does not alter single dose saquinavir pharmacokinetics in women. Br J Clin Pharmacol 2004 Mar;57(3):244-52.