Medicine interactions with Caffeine

Caffeine supplements are effective in matters of weight loss, mental alertness, and stimulating the nervous system; however, when taking caffeine be mindful about taking it at the same time as other medicines or supplements. If you are unsure about the safety of caffeine along with a medications you are presently taking consult your pharmacist or healthcare expert for advice. Be mindful of the following medicine interactions when taking caffeine:

Major interactions:

Stimulant drugs like Ephedrine speed up the nervous system and should not be taken with caffeine as both have stimulant properties. Taking caffeine along with Ephedrine may cause excess stimulation and cause serious side effects like heart problems. Do not take products that contain caffeine at the same time as Ephedrine.

Moderate interactions:

Adenosine (Adenocard) is used at times by doctors to test the heart during a cardiac stress test. Caffeine may block the effects of adenosine (Adenocard) and all products that contain caffeine should be avoided for at least 24 hours before a cardiac stress test.

The body naturally works to break down caffeine and get rid of it; however certain antibiotics may decrease how quickly the body can break down the caffeine. Taking antibiotics along with products that contain caffeine may increase the side effects of the caffeine. These may include jitteriness, increased heart rate, headaches, and other side effects. Antibiotics that decrease how quickly the body breaks down and expels caffeine include:

  • ciprofloxacin (Cipro)
  • enoxacin (Penetrex)
  • norfloxacin (Chibroxin, Noroxin)
  • sparfloxacin (Zagam)
  • trovafloxacin (Trovan)
  • grepafloxacin (Raxar)

Cimetidine (Tagamet) decreases how quickly your body breaks down caffeine. Taking the two together may increase the risk of caffeine side effects like jitteriness, fast heartbeats, headache, and others.

The body breaks down clozapine (Clozaril) to get rid of it, but caffeine may decrease how quickly this process can be carried out. Taking clozapine (Clozaril) along with caffeine may increase the side effects of clozapine (Clozaril).

Caffeine may also block the effects of dipyridamole (Persantine), which is often used by doctors to test the heart during a cardiac stress test. For this reason, you should stop using any products that may contain caffeine at least 24 hours before a cardiac stress test.

Disulfiram (Antabuse) decreases how quickly the body can get rid of caffeine. Taking the two together may increase caffeine side effects like jitteriness, irritability, hyperactivity, and others. Oestrogen should not be taken with caffeine because the body works to break down and get rid of caffeine, but oestrogen decreases how quickly that can be done. You should try to limit your caffeine intake if you are taking oestrogen as caffeine side effects may increase. Caffeine should be used with caution if you are taking the following Oestrogen pills:

  • conjugated equine oestrogens (Premarin)
  • ethinyl estradiol
  • estradiol

Fluvoxamine (Luvox) interacts with caffeine because the body breaks down caffeine to get rid of it, but Fluvoxamine (Luvox) decrease the speed of the process. Taking the two together may cause too much caffeine in the body and increase caffeine side effects.

Lithium interacts with Caffeine. While the body works to naturally get rid of lithium, caffeine can increase how quickly this process gets done. If you are taking products that contain caffeine as well as lithium, you should slowly be cut back on the caffeine. Abruptly cutting out caffeine altogether may increase side effects of lithium.

Medications that are used to treat depression (MAOIs) interact with caffeine. Caffeine works as a stimulant in the body and so do antidepressants. Taking the two together may have serious side effects and increase side effects of caffeine. Some of these medications that are used to treat depression are:

  • phenelzine (Nardil)
  • tranylcypromine (Parnate)

Medications that slow down blood clotting (Anticoagulant/Antiplatelet drugs) should not be taking with caffeine as they interact negatively. Caffeine may slow blood clotting and taking along with medications that also slow blood clotting may increase the risk of bruising and bleeding. Some of these medications include:

  • aspirin
  • clopidogrel (Plavix)
  • diclofenac (Voltaren, Cataflam, others)
  • ibuprofen (Advil, Motrin, others)
  • naproxen (Anaprox, Naprosyn, others)
  • dalteparin (Fragmin)
  • enoxaparin (Lovenox)
  • heparin
  • warfarin (Coumadin)

Caffeine's stimulant effects can hinder the sleep-producing effects of pentobarbital. Taking caffeine along with Phenylpropanolamine may cause too much stimulation on the body and increase heart rate, blood pressure, and cause nervousness.

The body breaks down riluzole (Rilutek) to get rid of it, but caffeine may decrease how fast this process can take place. It may also increase the side effects of riluzole (Rilutek).

Stimulant drugs interact with caffeine and speed up the nervous system causing jittery feelings and increased heart rate. Taking stimulant drugs and caffeine together may cause serious side effects like increased heart rate and high blood pressure. For this reason you should avoid taking stimulant drugs and caffeine together. Some stimulant drugs are:

  • diethylpropion (Tenuate)
  • epinephrine
  • phentermine (Ionamin)
  • pseudoephedrine (Sudafed)

Theophylline interacts with caffeine. The body works to get rid of theophylline, but caffeine may decrease the speed of this process. Taking the two together may also increase the side effects of theophylline.

Verapamil (Calan, Covera, Isoptin, Verelan) interacts with caffeine and decreases how quickly the body can break down and get rid of caffeine. Taking these two together may increase the risk of caffeine side effects like jitteriness, headache, and increased heart rate. Other moderate medicine interactions to watch out for are:

  • Alcohol and caffeine
  • Birth control pills and caffeine
  • Fluconazole and caffeine
  • Diabetes medications and caffeine