Drug interactions
Ethinyl estradiol-levonorgestrel + Tizanidine
Severity: Moderate
Ethinyl estradiol-levonorgestrel and Tizanidine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Ethinyl estradiol can reduce the clearance of tizanidine, a drug that depends heavily on CYP1A2 for its metabolism. Higher tizanidine exposure may cause more pronounced hypotension, bradycardia and sedation.
What this interaction means in plain words
Ethinyl estradiol-levonorgestrel and Tizanidine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Ethinyl estradiol-levonorgestrel belongs to Endocrine; Tizanidine belongs to Musculoskeletal.
Why it happens
Ethinyl estradiol inhibits CYP1A2, reducing the first-pass and systemic metabolism of tizanidine.
What to do
Monitor blood pressure, heart rate and sedation when starting or stopping the contraceptive in a patient on tizanidine. Reduce the tizanidine dose if adverse effects appear.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Ethinyl estradiol-levonorgestrel
- Ethinyl estradiol-levonorgestrel + Fezolinetant Contraindicated
- Ethinyl estradiol-levonorgestrel + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-levonorgestrel + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-levonorgestrel Major
- Amobarbital + Ethinyl estradiol-levonorgestrel Major
- Anastrozole + Ethinyl estradiol-levonorgestrel Major
Other interactions of Tizanidine
- Ciprofloxacin + Tizanidine Contraindicated
- Fluvoxamine + Tizanidine Contraindicated
- Pefloxacin + Tizanidine Contraindicated
- Pipemidic acid + Tizanidine Contraindicated
- Benzhydrocodone / acetaminophen + Tizanidine Major
- Brexanolone + Tizanidine Major
Frequently asked questions
Can I take Ethinyl estradiol-levonorgestrel with Tizanidine?
MediHelp rates the interaction as moderate. Ethinyl estradiol-levonorgestrel and Tizanidine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Ethinyl estradiol can reduce the clearance of tizanidine, a drug that depends heavily on CYP1A2 for its metabolism. Higher tizanidine exposure may cause more pronounced hypotension, bradycardia and sedation.
How serious is the interaction between Ethinyl estradiol-levonorgestrel and Tizanidine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure, heart rate and sedation when starting or stopping the contraceptive in a patient on tizanidine. Reduce the tizanidine dose if adverse effects appear.
What other medicines interact with Ethinyl estradiol-levonorgestrel?
MediHelp also lists interactions of Ethinyl estradiol-levonorgestrel with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir and dasabuvir, Tranexamic acid. The full list is on the Ethinyl estradiol-levonorgestrel page.
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