Selected Protease Inhibitors/Contraceptives Interactions
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
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 or additional form of birth control. Contact your doctor if you experience breakthrough bleeding, spotting, or pregnancy.Emergency contraceptives may be less effective also. You may need a larger dose than normal. Discuss the dose and the need to confirm that you do not become pregnant with a pregnancy test with your healthcare professional.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 March, 2018.
- 2.Lexiva (fosamprenavir calcium) US prescribing information. GlaxoSmithKline March, 2019.
- 3.Aptivus (tipranavir) US prescribing information. Boehringer Ingelheim Pharmaceuticals, Inc. June, 2018.
- 4.Prezista (darunavir) US prescribing information. Tibotec Inc. May, 2019. 5.Kaletra (lopinavir/ritonavir tablets) US prescribing information. Abbott Laboratories November, 2018.
- 5.Viracept (nelfinavir mesylate) US prescribing information. Agouron Pharmaceuticals, Inc. September, 2016.
- 6.Norvir (ritonavir) US prescribing information. Abbott Laboratories November, 2018.
- 7.Fortovase (saquinavir) US prescribing information. Roche Laboratories, Inc. December, 2004.
- 8.Invirase (saquinavir mesylate) US prescribing information. Roche Laboratories, Inc. March, 2019.
- 9.Nor-Q-D (norethindrone) US prescribing information. WatsonPharma March, 2005.
- 10.Medicines and Healthcare products Regulatory Agency. Levonorgestrel-containing emergency hormonal contraception: advice on interactions with hepatic enzyme inducers and contraceptive efficacy. available at: https://www.gov.uk/drug-safety-update/levonorgestrel-containing-emergency -hormonal-contraception-advice-on-interactions-with-hepatic-enzyme-induce rs-and-contraceptive-efficacy September 15, 2016..
- 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.
CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.