Drug Interaction Checker

Find out if your medicines are safe to take together.

1 Add each medicine you take: the brand on the box or the medicine inside it.
2 We check every pair, including each ingredient of combination medicines.
3 See what could happen and what to do, in plain language.

Your medicines

Serious interaction found

At least one pair of your medicines should not be taken together without a doctor's advice. Read the details below and talk to your doctor or pharmacist before your next dose.

1 Major 1 Moderate 1 pair checked

2 interactions

Opifen contains Fentanyl Clarithromycin

Major

CYP3A4 inhibition raises fentanyl levels, risking fatal respiratory depression.

What should I do?

These medicines can affect each other in a serious way. Do not start taking them together unless your doctor has said it is OK. If you already take both, do not stop either one on your own: speak to your doctor or pharmacist soon.

Clinical management: Avoid or monitor closely and reduce fentanyl dose.

Opifen Fentanyl Citrate Clarithromycin

Moderate

Clarithromycin is one of the medicines that can make fentanyl citrate work more strongly or for longer than expected when the two are taken together. The leaflet also lists some other medicines in the same group, including ketoconazole, itraconazole and troleandomycin, as well as the CNS depressant drugs (medicines that slow down the brain and nervous system).

What should I do?

These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.

Feeling unwell after taking your medicines? For an emergency call 999. For free advice from a doctor, call the 16263 health line (Shasthya Batayon), any time.

What do Major, Moderate and Minor mean?

Major

The combination can cause serious harm or stop a medicine from working. Usually avoided, or only used with close medical supervision.

Moderate

The combination may need care: a different dose, taking them at different times, or extra check-ups.

Minor

Little or no effect is expected. Usually nothing needs to change.

Duplicate

Two of your medicines contain the same ingredient, which can add up to a double dose.

Important: This checker lists interactions found in medicine leaflets and may not be complete. It does not know your dose, your health conditions, or food and supplement interactions. Never start, stop or change a medicine because of this tool alone: ask a registered doctor or pharmacist.