Paullinia cupana

Related Terms

Brazilian cocoa, caffeine, caffeine-tannin complex, Dark Dog Lemon?, elixir of youth, gift of the gods, Go Gum?, guarana bread, guarana gum, guarana paste, Guarana Rush?, guarana seed paste, guaranin, guaranine, Guts?, Happy Motion?, Josta?, mysterious Puelverchen, pasta guarana, Paullinia, Paullinia cupana, Paullinia sorbilis, Sapindaceae (family), Superguarana, tetramethylxanthine, Uabano, Uaranzeiro, Zoom?.

Background

Guarana is a native species of South America and has stimulating properties when taken by mouth. Guarana is also used to enhance athletic performance and to reduce fatigue. It has been used in the past as an aphrodisiac, diuretic, astringent, and to prevent malaria and dysentery, diarrhea, fever, headache, and rheumatism.
The active ingredient in guarana was formerly called guaranine (tetramethylxanthine), but was later found to be caffeine. Guarana has one of the highest caffeine contents of all plants (up to 7%), and has been used by manufacturers for its caffeine content (e.g., Dark Dog Lemon?, Guts?, and Josta?).
Although there is no scientific evidence that guarana itself increases mental alertness, its relationship to caffeine makes it probable that it would possess the same effects. It is proposed that the stimulatory effect of guarana is more gradual and sustained than caffeine due to the caffeine-tannin complex. Guarana is generally regarded as safe when not combined with other stimulatory agents, such as ephedra.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *


Guarana has not been shown to alter cognitive function or arousal in preliminary studies. Caffeine found in guarana may improve simple reaction time, but may not improve immediate memory. Additional study is needed in this area.

 C


Guarana has not been shown to alter cognitive function or arousal in preliminary studies. Caffeine found in guarana may improve simple reaction time, but may not improve immediate memory. Additional study is needed in this area.

 C


Caffeine may have positive effects on mood, and may increase alertness and feelings of well-being. Additional study is needed in this area.

 C


Caffeine may have positive effects on mood, and may increase alertness and feelings of well-being. Additional study is needed in this area.

 C


Caffeine has been used as a weight loss agent due to its thermogenic effects (the process of fat or calorie burning caused by increasing heat output). In available studies, guarana has been studied with other herbs making it difficult to draw a conclusion based on the effects of guarana alone. Additional study is needed in this area.

C


Caffeine has been used as a weight loss agent due to its thermogenic effects (the process of fat or calorie burning caused by increasing heat output). In available studies, guarana has been studied with other herbs making it difficult to draw a conclusion based on the effects of guarana alone. Additional study is needed in this area.

C
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

Dosing

Adults (over 18 years old)
There is no proven effective dose for guarana. Teas, capsules and energy drinks are all commercially available. For cognitive enhancement, a single dose of 150 milligrams guarana dry extract, standardized to 11-13% alkaloid concentration has been used. One gram of guarana up to four times a day has been taken to relieve diarrhea or dysentery. As a diuretic, 486 milligrams of guarana daily has been used. One to two tablets or capsules (200-800 milligrams guarana extract) before breakfast or lunch, not to exceed 3 grams daily, has reportedly been used for energy enhancement.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Interactions

Interactions with Drugs
Although the interactions for guarana are quite limited, there are numerous theoretical interactions based on guarana's caffeine content.
Caffeine combined with analgesics (pain relievers) has been reported to increase analgesic effects. For example, in treatment of migraine, a combination of N-acetyl-para-aminophenol acetaminophen (APAP), aspirin, and caffeine was found to be highly effective. Caffeine may also be beneficial when taken with ibuprofen or propyphenazone. Caffeine increases the peak plasma concentration, rate of absorption and bioavailability of aspirin. The addition of caffeine to aspirin has significant benefits on mood and performance. An aspirin/butalbital/caffeine/codeine combination is considered superior to acetaminophen/codeine in relieving oral surgery pain.
Caffeine is an adenosine antagonist and inhibits A1-receptors. Therefore the actions of caffeine are directly negated by adenosine and adenosine directly negates the effects of caffeine.
Alcohol consumption may increase caffeine serum concentrations and the risk of caffeine adverse effects.
There is one case report of ischemic stroke after the nasal ingestion of amphetamine and caffeine. Caution is advised with this combination.
Caffeine has been reported to have antiplatelet activity, and may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin?) or heparin, anti-platelet drugs such as clopidogrel (Plavix?), and non-steroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen (Motrin?, Advil?) or naproxen (Naprosyn?, Aleve?). Caffeine was also shown to attenuate the hemodynamic response to dipyridamole, a rheologic agent that inhibits platelet aggregation.
Caffeine may also alter blood sugar levels. Caution is advised when using medications that may also alter blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Caffeine may interact with benzodiazepines. When lorazepam and caffeine were given and mental performance tests were administered and compared, the effect of caffeine counteracted both the effect of reducing anxiety and the reduction in mental performance caused by lorazepam alone. Caffeine with diazepam (Valium?) may produce similar results by counteracting the drowsy effects and mental slowness of diazepam. The caffeine in guarana may also negate the hypnotic effects of pentobarbital. Sedative doses may need to be monitored.
Concomitant use of guarana may increase the inotropic effects of beta-adrenergic agonists.
Caffeine may alter the effects of carbamazepine (Tegretol?) and reduce the bioavailability. Consult with a qualified healthcare professional, including a pharmacist, as dosing adjustments may be necessary.
The antihistamine cimetidine (Tagamet?) may decrease caffeine clearance by inhibiting the microsomal metabolism of caffeine. Caution is advised in patients taking cimetidine along with caffeine or guarana.
The antibiotic ciprofloxacin (Cipro?) significantly inhibits caffeine elimination. Caution is advised in patients taking certain antibiotics and caffeine.
Caffeine taken with the antipsychotic clozapine (Clozaril?, Leponex?) may increase the risk of unwanted side effects, such as tardive dyskinesia, hallucinations, and akathisia. Caution is advised.
Concomitant use of central nervous system stimulants and caffeine may increase the risk of stimulant adverse effects.
Caffeine may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be decreased or increased in the blood, and alter the intended effects. Patients taking any medications should check the package insert and speak with a qualified healthcare professional, including a pharmacist, about possible interactions. Examples of agents that may interact include riluzole or fluvoxamine
Numerous agents alter the clearance, metabolism, and pharmacokinetics of caffeine when taken concurrently. For instance, when caffeine is taken with the steroid agent dexamethasone (Decadron?), the clearance of caffeine may increase. Antibacterial agents such as enoxacin may significantly inhibit caffeine elimination. Impaired iron metabolism and microcytic anemia may occur in infants of breastfeeding women consuming caffeine. Methoxsalen and mexiletine have been shown to decrease the clearance of caffeine. Concomitant use of birth control pills and caffeine may increase serum caffeine concentrations and increase the risk of adverse effects, as birth control pills decrease the rate of caffeine clearance. Disulfiram decreased clearance of caffeine in normal volunteers. Caffeine administration in patients pretreated with quinolones (norfloxacin or pipemidic acid) may result in decreased caffeine clearance. Caffeine degradation may be impaired by phenytoin (Dilantin?), an anticonvulsant drug.
Caffeine may increase urination, urinary sodium, and potassium excretion. Caution is advised in patients taking other diuretics (water pills), due to possible additive effects.
Ephedrine in combination with guarana may increase blood pressure and therefore the risk of stroke and other cardiovascular events. Thermogenic synergism between ephedrine and caffeine may enhance the activity of ephedrine. Theoretically, pseudoephedrine (Sudafed?) would be expected to have the same effect on blood pressure when used in combination with guarana.
Caffeine may enhance the effectiveness of ergotamine tartrate (Cafergot?) in the treatment of migraine headaches. Caffeine may enhance topically applied (on the skin) hydrocortisone in the treatment of atopic dermatitis.
In preterm infants, caffeine has been found to be equivalent to theophylline in altering erythropoietin production, a hormone made in the kidneys. Theophylline is also used as a bronchodilator agent, and given to asthmatics. Caffeine may decrease total body clearance and elimination rate of theophylline. Caution is advised.
In a case report, esmolol was an effective treatment of caffeine toxicity resulting from a suicide attempt of ingesting excessive amounts of caffeine.
Caffeine may increase the renal (kidney) clearance of lithium and may reduce the plasma levels in stabilized patients. Abrupt discontinuation of a consistent caffeine intake may cause an increase in lithium tremors and an increase in serum lithium levels. Monitoring of doses may be necessary.
Although not well studied in humans, caffeine and monoamine oxidase inhibitors (MAOIs) may cause encephalopathy (degenerative brain disease), neuromuscular irritability, hypotension (low blood pressure), sinus tachycardia (increased heartbeat), rhabdomyolysis (potentially fatal disease involving destruction or degeneration of skeletal muscle) and hyperthermia (abnormally high body temperature). Consult with a qualified healthcare professional, including a pharmacist, to check for any interactions.
Caffeine may have additive effects on cardiovascular parameters when taken with nicotine. Concomitant consumption of caffeine and cigarettes during pregnancy may place the developing fetus at higher risk for diminished growth.
The combination of phenylpropanolamine and caffeine caused a manic psychosis in one woman with no previous history of mental disturbances. It is noted that phenylpropanolamine can increase the peak levels reached by caffeine by almost four-fold. An additive increase in blood pressure has occurred when using the combination of phenylpropanolamine and caffeine. Caution is advised.
Terbinafine (Lamisil?) is an antifungal agent that may increase serum caffeine concentrations and increase the risk of adverse effects. Caution is advised when taking terbinafine concurrently with caffeine.
Verapamil is a calcium channel blocker agent. When taken with caffeine, verapamil may increase the risk of side effects.

Attribution

This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

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