Drug Interactions between Duragal-S and elbasvir / grazoprevir
This report displays the potential drug interactions for the following 2 drugs:
- Duragal-S (belladonna/ergotamine/phenobarbital)
- elbasvir/grazoprevir
Interactions between your drugs
PHENobarbital elbasvir
Applies to: Duragal-S (belladonna / ergotamine / phenobarbital) and elbasvir / grazoprevir
Consumer information for this interaction is not currently available.
CONTRAINDICATED: Coadministration with potent inducers of CYP450 3A4 may significantly decrease the plasma concentrations of elbasvir and grazoprevir, both of which are substrates of the isoenzyme. In 10 study subjects, administration of elbasvir 50 mg once daily with efavirenz 600 mg once daily decreased elbasvir peak plasma concentration (Cmax), systemic exposure (AUC) and trough plasma concentration (Cmin) by 45%, 54% and 59%, respectively, compared to administration of elbasvir alone. Likewise, when grazoprevir 200 mg once daily and efavirenz 600 mg once daily were given together to 12 study subjects, grazoprevir Cmax, AUC and Cmin decreased by 87%, 83% and 69%, respectively. Efavirenz is generally considered a moderate inducer of CYP450 3A4. More potent inducers such as carbamazepine or phenytoin may interact to an even greater extent.
MANAGEMENT: Given the risk of reduced viral susceptibility and resistance development associated with subtherapeutic antiviral drug levels, concomitant use of elbasvir-grazoprevir with efavirenz or potent CYP450 3A4 inducers is considered contraindicated.
References
- "Product Information. Zepatier (elbasvir-grazoprevir)." Merck & Co., Inc (2016):
PHENobarbital grazoprevir
Applies to: Duragal-S (belladonna / ergotamine / phenobarbital) and elbasvir / grazoprevir
Using grazoprevir together with PHENobarbital is not recommended. Combining these medications may significantly reduce the blood levels of grazoprevir, which may make the medication less effective in treating hepatitis C. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
ergotamine PHENobarbital
Applies to: Duragal-S (belladonna / ergotamine / phenobarbital) and Duragal-S (belladonna / ergotamine / phenobarbital)
PHENobarbital may reduce the blood levels and effects of ergotamine. Contact your doctor if your symptoms worsen or your condition changes during treatment with these medications. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Drug and food interactions
PHENobarbital food
Applies to: Duragal-S (belladonna / ergotamine / phenobarbital)
Ask your doctor before using PHENobarbital together with ethanol, this can add to dizziness, drowsiness and other side effects of PHENobarbital. Be careful if you drive or do activities that require you to be awake and alert. Talk with your doctor before using any medications together, or drinking alcohol with PHENobarbital. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
ergotamine food
Applies to: Duragal-S (belladonna / ergotamine / phenobarbital)
Grapefruit juice may increase the blood levels of certain medications such as ergotamine. You may want to limit your consumption of grapefruit and grapefruit juice during treatment with ergotamine. However, if you have been regularly consuming grapefruit or grapefruit juice with the medication, then it is advisable for you to talk with your doctor before changing the amounts of these products in your diet, as this may alter the effects of your medication. Contact your doctor if your condition changes or you experience increased side effects. Orange juice is not expected to interact.
belladonna food
Applies to: Duragal-S (belladonna / ergotamine / phenobarbital)
Ask your doctor before using belladonna together with ethanol. Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking belladonna. You should be warned not to exceed recommended dosages and to avoid activities requiring mental alertness. If your doctor prescribes these medications together, you may need a dose adjustment to safely take this combination. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
ergotamine food
Applies to: Duragal-S (belladonna / ergotamine / phenobarbital)
Nicotine may increase the effects of ergotamine in narrowing the blood vessels and decreasing blood flow. A severe decrease in blood flow to the brain and other parts of the body can lead to dangerous side effects. Contact your doctor immediately if you experience coldness, paleness, discoloration, numbness, tingling, or pain in your hands or feet; muscle pain or weakness; severe or worsening headache; blurred vision; severe abdominal pain; chest pain; or shortness of breath while using these medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
grazoprevir food
Applies to: elbasvir / grazoprevir
Information for this minor interaction is available on the professional version.
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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