Mucuna pruriens – Contraindications and warnings
Mucuna has some drawbacks. In principle, the levodopa in itself (albeit with other natural ingredients that improve tolerance) shares many of the contraindications and precautions applicable to synthetic levodopa. These warnings are well known and we will review some of them.
I want to begin by highlighting the main stumbling block to the beneficial use of mucuna: ignorance on the part of the patient and lack of medical information. A physician should monitor treatment at all times.
A major obstacle to treatment with mucuna is that pa-tients don’t have clear ideas about the drugs’ intended purpose
They have heard of several cases where mucuna worked well, but usually these observations have come to them from people without any scientific knowledge, from non-professional websites or from commercial information intended for product sales.
Mucuna is sold freely on the Internet and many patients take it without medical supervision. Worse still, they engage in speculation based on bizarre opinions they encounter in the forums, and they absorb this erroneous information, and therefore lack sufficient knowledge to use it appropriately. However, occasionally patients are right or are very close to the truth, but there is still a danger of misuse. At times patients take mucuna simply because despair leads them to try anything.
Many patients complain of the disdainful reaction they encounter when they ask their doctors about adding mucuna to their treatment regimen.
As it is an “unorthodox” therapy, it is perfectly understandable that the physician does not want to prescribe mucuna: it is not part of the generally accepted body of treatments they are trained to manage..
When a doctor decides to incorporate mucuna, he faces new difficulties, particularly with patients treated with other drugs. This requires the additional effort of studying the situation and designing a strategy for each individual case.
On the other hand, we cannot allow patients to treat themselves in hiding. Therefore, it is desirable that as doctors, we have to educate ourselves about mucuna so that we can choose to use it or not in a particular type of patient.
One should never despise the unfamiliar. After studying the properties of mucuna and weighing its advantages and disadvantages, we should decide on a rational basis, whether it is beneficial, neutral, or inadvisable for a specific case.
If the patient perceives that we master the subject, he will entrusted his care to us, rather than attempting to treat himself. That way, he will cooperate if we ban the mucuna or recommend a gradual dosage pattern. We earn their trust when we have enough information and credibility.
Mucuna is not a placebo but, rather, has important effects. However anyone can buy it without a prescription, and most are taking it without medical supervision. These patients are not sufficiently familiar with the properties of mucuna, they do not know the side effects or complications that may arise; they do not take into account the interactions with other medications or the differences between individuals.
While this scenario suggests a public health issue, it fortunately does not usually cause serious problems. Why?
I think that one reason is the safety of the components of mucuna, which has been used for millennia in thousands or hundreds of thousands of patients in India without significant harmful effects.
Another issue is that the products are sold often in small doses as a dietary supplement. That is not, however, always the case: there are some preparations with excessive doses especially when combined with carbidopa (in Sinemet, Madopar or Stalevo), dopamine agonists or other antiparkinsonian drugs. It is necessary to use extreme caution.
Although better tolerated, mucuna contains a natural form of levodopa. In theory it should share the same contraindications, interactions and precautions of synthetic levodopa:
It is contraindicated in children, pregnancy and lactation (prolactin inhibition) and schizophrenia or psychosis.
It should be used with caution (and is best avoided) in cases of a medium to severe degree of heart disease or diabetes.
Do not take it with MAOIs, or with ergot.
Use caution (due to the additive effect) if the patient takes Levodopa (Sinemet, Madopar), COMT inhibitors (Entacapone Stalevo) or dopamine Agonists (rotigotine, pramipexole, ropinirole).
Neuroleptics antiemetics: metoclopramide (Reglan).
Ayahuasca and other psychoanaleptics.
Nonselective MAOI (contraindicated).
Use caution with MAO-B; evaluate individual responses.
Anticholinergics. Dopamine uptake inhibitors.
Levodopa and beans (additive effect).
Ergot and other dopaminergics (additive effect).
Antihypertensives, antidepressants, sedatives, alpha blockers (prostate therapy): they may promote orthostatic hypotension.
Substances which inhibit the absorption of levodopa: spiramycin, salts of iron, antacids (dyspepsia).
To avoid use in individuals with known allergy or hypersensitivity to Mucuna pruriens or components.
There have been some side effects of mucuna. In a study of patients with Parkinson’s disease, a derivative of Mucuna pruriens caused minor adverse effects, which were mainly gastrointestinal in nature.
Isolated cases of acute toxic psychosis have been reported1, probably due to levodopa content. Therefore, as with Sinemet and Madopar, its use should be avoided in patients with psychosis or schizophrenia
We assume that all contraindications, interactions, precautions and side effects that we know about synthetic levodopa should be considered when taking levodopa from mucuna.
Specific contraindications include thinning of the blood (anticoagulants), and care should be taken with antiplatelet and anti-inflammatory drugs because mucuna increases clotting time.
Mucuna should not merge with anticoagulants (Sintrom, Dabigatran, heparin, warfarin) or with antiplatelet drugs such as clopidogrel. Caution should be exercised and the additive effect should be taken into account if it is associated with acetylsalicylic and NSAIDs (nonsteroidal anti-inflammatory).
We should also be careful with antidiabetic medicines: mucuna lows glycemic index, and thus is to be considered a potential additive effect. Other interactions are possible, so always consult your regular doctor.
On the one hand, it can be argued that mucuna has been used for many centuries in India and has been available for several years online without a prescription, and yet serious problems have not been revealed. But that is just an observation.
Regarding Sinemet and Madopar, we have thousands of controlled studies, while publications on mucuna are still scarce. One must therefore use greater caution when choosing mucuna. While the future appears to be positive, we need the confirmation of more scientific studies.
Green tea enhances the effect of beans in general and of mucuna in particular. This effect can also be seen in patients taking Sinemet or Madopar: you should know this phenomenon due to the increase in potency it can cause.
There is something in green tea that acts like carbidopa. It contains polyphenols which inhibit dopa-decarboxylase2
an action similar to that carried out by the carbidopa or benserazide contained in Sinemet or Madopar.
In addition, there is something that acts like entacapone in green tea. Ponifenol, EGCG (Epi-Gallo-Catecin-gallate) promotes the entry into the brain of levodopa and prolongs its bioavailability in the blood because it inhibits the COMT enzyme3.
This action is similar to that of entacapone; namely beans mixed with green tea have Stalevo-like effects, but with different proportions. Obviously, if you take levodopa (mucuna or otherwise), its effectiveness will be reinforced and this should be taken into account as there is risk of overdose. Always consult your doctor.
These “carbidopa-like” and “entacapone-like” effects can be seen with green tea and they are independent of their other neuroprotective benefits4 so the tea is recommended in many Parkinson’s patients.
- Infante ME et al. Outbreak of acute toxic psychosis attributed to Mucuna pruriens. Lancet 1990; 336:1129 ↩
- Bertoldi M, Gonsalvi M, Voltattorni CB. Green tea polyphenols: novel irreversible inhibitors of dopa decarboxylase. Biochem Biophys Res Commun 2001; 284:90-93. ↩
- Kang KS et al. Dual beneficial effects of (-) epigallocatechin-3-gallate on levodopa methylation and hippocampal neurodegeneration: in vitro and in vivo studies. PLoS One 2010; 5(8):e11951. doi: 10.1371/journal. ↩
- Guo S et al. Protective effects of green tea polyphenols in the 6-OHDA rat model of Parkinson’s disease through inhibition of ROS-NO pathway. Biol Psychiatry 2007; 62:1353-1362. ↩