Inderal LA may interact with other medicines. It is extremely important for you to tell your doctor about all the medicines you are currently taking, including your over-the-counter (non-prescription) medicines. The migraine journal can help you keep a list of all of your medicines. It is also important that you tell your doctor if you are taking any dietary supplements such as herbs or vitamins. Your doctor can best help you avoid any unpleasant side effects or adverse reactions, as well as drug interactions, if he or she knows about everything that you are taking.
NOTE: All drug interaction studies have been conducted with fast-acting propranolol, not the extended-release formula found in Inderal LA capsules. There is currently no information on the side effects that can occur when other drugs are taken specifically with Inderal LA capsules.
Drug Interactions with Inderal LA and Medicines Broken Down by the Liver
The active ingredient in Inderal LA — propranolol — is broken down by the liver. Taking Inderal LA with another medicine that is also broken down by the liver can lead to dangerous side effects and/or changes in the effectiveness of the medicines. Talk with your doctor or pharmacist about whether any of your current prescription and over-the-counter medicines affect your liver. If they do, develop a plan with your doctor to ensure that taking Inderal LA does not over-tax your liver or affect liver function.
Drug Interactions with Inderal LA and Medicines That Raise or Lower Propranolol
Here are some prescription medicines that can increase the levels of propranolol in the bloodstream to possibly dangerous levels if taken along with Inderal LA. Taken together, Inderal LA and the following medicines may cause your blood pressure and heart rate to drop too low.
- Cipro, Cipro XR, Proquin XR (ciprofloxacin)
- Cordarone (amiodarone)
- Diflucan (fluconazole)
- Luvox (fluvoxamine)
- Maxalt (rizatriptan)
- Norvir (ritonavir)
- Nydrazid, Laniazid (isoniazid)
- Paxil, Paxil CR, Pexeva (paroxetine)
- Prozac, Sarafem (fluoxetine)
- Theo-Dur, Respbid, Slo-Bid, Theo-24, Theolair, Uniphyl, Slo-Phylli (theophylline)
- Tofranil (imipramine)
- Zomig (zolmitriptan)
Taking Inderal LA along with the following medicines may lower your body’s levels of propranolol (the active ingredient in Inderal LA), which may make the Inderal LA less effective:
- Dilantin (phenytoin)
- Luminal (phenobarbital)
- Rifadin (rifampin)
- Ethanol (alcohol)
Inderal LA and Cigarette Smoking
Cigarette smoking speeds up the liver’s breakdown of propranolol (the active ingredient in Inderal LA) by 77%. This can lower the amount of propranolol in your bloodstream, which may affect the dosage of Inderal LA that you will need in order to treat your high blood pressure or prevent chest pain or migraine attacks. If you smoke or use other tobacco products and are taking Inderal LA, tell your doctor so that he or she can adjust your dosage of propranolol if needed. You may also want to talk with your doctor about quitting smoking. Not only can smoking affect how your body uses Inderal LA and other medicines, but it also can raise your risk for developing many serious health problems.
Inderal LA and Cardiovascular Drugs
Taking Inderal LA with other medicines that lower blood pressure and heart rate can cause a dangerous drop in your blood pressure and/or heart rate. Your doctor should monitor you closely when prescribing Inderal LA with such medications, including these:
- ACE inhibitors (Angiotensin Converting Enzyme inhibitors)
- Alpha blockers (some examples are Cardura, Hytrin, Flomax)
- Calcium channel blockers (some examples are Norvasc, Cardizem, Procardia)
- Drugs affecting heart rhythm such as Rythmol (propafenone) or Cordarone (amiodarone)
- Catapres, Catapres-TTS, Jenloga (clonidine)
- Hydropres (reserpine)
- Lanoxin (digoxin)
Inderal LA and Nonsteroidal Anti-Inflammatory Drugs (NSAIDS)
NSAIDS such as Indocin, Indocin-SR (indomethacin) may make Inderal LA less effective at lowering high blood pressure and heart rate when the two types of medicines are taken together. For this reason, talk to your doctor before taking Inderal LA or another form of propranolol along with a medicine that is labeled an NSAID.
Inderal LA and Antidepressants
Taking Inderal LA along with MAO inhibitors or tricyclic antidepressants (medicines used to treat depression) can cause blood pressure levels to drop too low. If you are taking any antidepressants such as these, be sure to tell your doctor before you begin taking Inderal LA or another form of propranolol.
Inderal LA and Coumadin (warfarin)
Taking Inderal LA with Coumadin (warfarin) will increase the levels of this blood thinner in the bloodstream. Your doctor should closely monitor your blood’s ability to clot if you are taking Inderal LA or another form of propranolol with the blood-thinner Coumadin.
Inderal LA and Haldol (haloperidol)
Dangerously low blood pressure and heart attack have been reported by people taking Inderal LA along with the antipsychotic medicine Haldol (haloperidol).
Written & reviewed by: Lisa Erwin R.Ph. CGP | Last review date: Dec 2010. Click the References Link below for a complete list of references.