Alyacen 1/35 Drug Interactions: What to Avoid and What to Tell Your Doctor

Alyacen 1/35 is generally safe and well-tolerated, but like any medication, it can interact with other drugs, supplements, and even certain foods. Some interactions can reduce the pill's effectiveness (putting you at risk for unintended pregnancy), while others can cause dangerous side effects. Here's everything you need to know.

Always Tell Your Doctor and Pharmacist Everything You Take

Before starting Alyacen 1/35, provide your prescriber and pharmacist with a complete list of everything you take — including prescription medications, over-the-counter (OTC) drugs, vitamins, minerals, herbal products, and supplements. Drug interactions can occur from all of these sources.

Severe Interactions (Contraindicated — Do Not Use Together)

• Ombitasvir/paritaprevir/ritonavir ± dasabuvir (HCV drug regimens): This combination (used to treat Hepatitis C) causes significantly elevated liver enzyme levels when combined with ethinyl estradiol-containing medications like Alyacen 1/35. ALT elevations of greater than 5-20x the upper limit of normal have been reported. Alyacen 1/35 must be discontinued before starting this HCV regimen and can be restarted approximately 2 weeks after completing treatment.

Major Interactions (Can Significantly Reduce Pill Effectiveness)

These medications increase the liver's metabolism of the hormones in Alyacen 1/35, reducing the amount of active hormone in your bloodstream and potentially compromising contraceptive efficacy. If you're on any of these, discuss alternative or additional contraception with your provider:

• Rifampin (antibiotic): A potent enzyme inducer used to treat tuberculosis and other infections. Rifampin dramatically increases the metabolism of both norethindrone and ethinyl estradiol, significantly reducing contraceptive efficacy. Use non-hormonal backup contraception during rifampin therapy and for 28 days after stopping it.

• Anticonvulsants (phenobarbital, phenytoin, carbamazepine, primidone, topiramate, oxcarbazepine): These anti-seizure medications are enzyme inducers that increase the metabolism of ethinyl estradiol and norethindrone. Use of these drugs with Alyacen 1/35 may result in breakthrough bleeding and reduced contraceptive effectiveness. Patients who need both should use additional non-hormonal contraception.

• Some HIV medications (certain protease inhibitors and non-nucleoside reverse transcriptase inhibitors): Some HIV drugs can either induce or inhibit the metabolism of oral contraceptive hormones. Consult your HIV specialist and gynecological provider about the specific interactions with your ART regimen.

Moderate Interactions (Worth Discussing with Your Provider)

• St. John's Wort (Hypericum perforatum): This popular herbal supplement is a known enzyme inducer that can reduce the plasma concentrations of oral contraceptive hormones, potentially reducing efficacy and causing breakthrough bleeding. Tell your provider if you use this supplement.

• Lamotrigine (Lamictal): Oral contraceptives (particularly the ethinyl estradiol component) can increase the metabolism of lamotrigine, reducing its plasma concentrations and potentially destabilizing seizure control. This bidirectional interaction requires close monitoring by your neurologist. Lamotrigine doses may need adjustment when starting or stopping oral contraceptives.

• Glecaprevir/pibrentasvir (Mavyret — HCV drug): Co-administration is not recommended due to potential for ALT elevations, similar to other HCV combination regimens.

• Colesevelam (Welchol): The bile acid sequestrant colesevelam can impair the absorption of certain drugs including ethinyl estradiol. Take Alyacen 1/35 at least 4 hours before colesevelam.

Food and Supplement Interactions

• Grapefruit juice: Grapefruit inhibits intestinal enzymes that metabolize estrogens, potentially raising ethinyl estradiol levels slightly. While not typically clinically significant at the doses in Alyacen 1/35, it's worth mentioning to your provider if you consume large amounts regularly.

• Ascorbic acid (Vitamin C) and acetaminophen: High-dose Vitamin C and acetaminophen may slightly increase ethinyl estradiol plasma concentrations by inhibiting its conjugation. At standard doses, this is not considered clinically significant.

Medications That Alyacen 1/35 Can Affect

Alyacen 1/35 can also affect the metabolism of other medications you take:

• May increase plasma levels of some drugs (e.g., theophylline, tizanidine, cyclosporine).

• May decrease plasma levels of some drugs (e.g., acetaminophen, morphine, lorazepam, temazepam) by inducing their glucuronidation.

• Can increase thyroid-binding globulin, potentially affecting thyroid hormone test interpretation (though clinical hypothyroidism is not caused).

What to Tell Your Prescriber and Pharmacist

Always disclose the following when starting Alyacen 1/35:

• All prescription medications (especially antibiotics, anticonvulsants, HIV drugs, psychiatric medications).

• All herbal supplements — especially St. John's Wort.

• Any OTC medications you use regularly.

• Whether you smoke and how many cigarettes per day.

The Bottom Line

Drug interactions with Alyacen 1/35 are manageable with proper communication with your healthcare team. The most important things to avoid are rifampin, enzyme-inducing anticonvulsants, and HCV combination regimens. If you're on any of these, your prescriber will work with you on the safest approach. For information on side effects, see our guide to Alyacen 1/35 side effects. And if finding Alyacen 1/35 in stock is your challenge, try medfinder.