What Are the Side Effects of Commonly Used Anti-Cancer Chinese Herbs and Patent Medicines?

Our renowned TCM educator, the well-known veteran physician Professor Zhang Tingmo, wrote in his book Clinical Chinese Materia Medica: "Chinese herbs have a certain toxicity, an objective fact confirmed by thousands of years of medication practice. According to incomplete statistics, in the last 90 years there have been 5,316 publicly reported Chinese-herb poisoning incidents in domestic medical literature, involving over 300 kinds of drugs (single herbs and patent medicines), among which 215 people died of poisoning. Although overall the toxicity of Chinese herbs is clearly less than that of chemical drugs, their existing toxicity should still be taken very seriously."

Besides these publicly reported Chinese-herb poisoning accidents, there are many unreported ones. Over the years I have encountered many cancer patients who were poisoned or developed side effects from Chinese herbs. Whether TCM or Western medicine, it is an undeniable fact that sometimes treatment not only fails to help the patient but accelerates death; this is an inherent risk of medicine. Reducing this risk to a minimum and treating patients as safely and effectively as possible is a goal every medical worker should strive for.

In oncology medication, toxic Chinese herbs make up a large proportion. Ancient and modern physicians have used toxic Chinese herbs to treat malignant sores, toxin-swellings, and stubborn fatal diseases like cancer and scabies, achieving definite efficacy and accumulating rich experience. But these toxic herbs, used clinically with the slightest carelessness, can also easily cause poisoning, even death.

Herbs such as Banmao (blister beetle), Pishuang (arsenolite), Xionghuang (realgar), Chan'su (toad venom), Maqianzi (nux-vomica), Shuiyin (mercury), Zhusha (cinnabar), and Mubiezi (momordica) are common oncology agents for attacking toxin and eroding sores; but all are highly toxic with low lethal doses. Historical literature is full of records of poisoning and even death from taking these herbs. Among modern patent anti-cancer medicines, Fufang Banmao Capsules, Demethylcantharidin Tablets, Pingxiao Tablets, Huachansu Tablets, Jinlong Capsules, Yushu Dan, and Liu Shen Wan also contain these highly toxic herbal components.

Not only such highly toxic herbs can cause poisoning or allergic reactions in patients; the overdose of common herbs and the long-term use of low-toxicity herbs can also easily cause chronic poisoning or allergic reactions.

For diseases like malignant tumors, without these poison-attacking-poison drugs a considerable proportion of patients would have no hope of survival; yet using these toxic herbs or patent medicines raises medication-safety issues. So both doctors and patients depend on and fear poison-attacking-poison herbs. Precisely because of this, both doctors and patients need sufficient understanding of the side effects of common anti-cancer herbs and patent medicines, so that when a poisoning or allergic reaction appears, measures are taken immediately, avoiding delay that causes greater harm.

On the other hand, we should also know that the toxicity of these herbs is precisely what makes them work, so there is no need to turn pale at the mention of poison. As long as the toxicity is kept within a range the body can bear, reasonably harnessing a herb's toxicity can also achieve the goal of treating disease. Many cancer patients take such toxic herbs and survive long-term, with the tumor shrinking or even disappearing.

Patients taking poison-attacking-poison herbs for cancer must do so under a doctor's guidance and contact the doctor promptly if allergic reactions or side effects appear. When necessary, even hospitalization can be considered, so the doctor can closely observe the patient's bodily reactions and act at any time.

Generally speaking, the allergic reactions and side effects of these herbs fall into the following categories:

The first is allergic (hypersensitivity) reaction, the most common, mainly manifesting as fever or skin allergy, or both. It often presents as allergic drug rash or urticaria-like lesions; in severe cases it can cause generalized exfoliative dermatitis, allergic purpura, or anaphylactic shock.

I have seen two patients with severe allergic reactions who developed generalized ulceration. I have also seen many with mild cutaneous drug rash. Generally, when such a hypersensitivity reaction first appears, the patient stops the medicine, drinks more water, eats more diuretic foods, and uses some anti-allergy drugs appropriately; the drug rash soon disappears.

Some folk TCM practitioners, when using poison-attacking drugs, require the patient to endure this hypersensitivity reaction, telling the patient it is "toxin expulsion." This is very dangerous. I saw a male patient with leiomyosarcoma who, believing this was a detox reaction, kept taking the medicine until he was covered in ulcers. I also saw a breast-cancer patient whom a folk TCM practitioner told this hypersensitivity reaction was a normal "disease-expulsion" response, resulting in large-area generalized ulceration and a period of high fever; yet their conditions were not controlled.

Generally, itchy skin marks the start of an allergic reaction. In most cases this happens because the kidneys are irritated; if checked at hospital, the creatinine often comes back abnormal. The patient should pause the Chinese herbs, drink more plain water or green tea to promote urination; mild cases generally return to normal within 24 to 72 hours. If ignored, the hypersensitivity reaction worsens. If the patient has trouble urinating, diuretic drugs may even be used to aid recovery.

For clinicians, when prescribing such herbs or patent medicines, this should also be considered: try to add diuretics like Fuling (Poria), Zhuling (Polyporus), and Huashi (Talcum) to the formula, and tell the patient to drink more water. When using highly toxic herbs, it may even be necessary to add Erchou (pharbitis) and Dahuang (rhubarb) as precipitating/purging agents to help the body expel toxin.

The second common side effect is gastrointestinal reaction, mainly manifesting as nausea, vomiting, poor appetite, abdominal distension, constipation, diarrhea, gastrointestinal bleeding, jaundice, hepatosplenomegaly, liver-function damage, toxic hepatitis, and even death.

Generally, such reactions arise when the patient's gastrointestinal tract and liver function are damaged. When this happens, the patient should stop the medicine promptly; in severe cases even food and water may need to be withheld, and the patient should seek the doctor's help.

The third category is cardiovascular reaction, mainly manifesting as palpitations, chest tightness, arrhythmia, conduction block, rising or falling blood pressure, heart failure, and death.

Such reactions mostly occur when some herbal components damage the patient's cardiac function. When taking herbs that may harm the heart, such as Mahuang (Ephedra), the patient should take a gradual approach: start with a small dose, increase gradually, and observe closely; at the first sign of trouble, immediately reduce the dose.

The fourth category is respiratory reaction, mainly manifesting as cough, hemoptysis, difficulty breathing, acute pulmonary edema, and respiratory failure.

Generally, if the patient had no such symptoms before taking the medicine but develops them afterward, he should contact the doctor promptly for help.

The fifth category is neurological reaction, mainly manifesting as numbness of the lips, tongue, and limbs; dizziness, headache, restlessness, convulsions, fright and palpitations, confusion, coma, and even death.

Many Chinese herbs have neurotoxic side effects; common anti-cancer herbs like Maqianzi (nux-vomica) and Mubiezi (momordica) have strong neurotoxic side effects, so patients must carefully watch their bodily reactions when taking them.

The sixth category is urinary reaction, mainly manifesting as lower-back pain, edema, oliguria, and even acute renal failure or death. This is mostly a side effect of severe kidney-function damage. When taking herbs and patent medicines containing highly toxic components such as Banmao/cantharidin, arsenic preparations, or mercury preparations, the patient must closely watch urine output; either an increase or a decrease means the kidneys are irritated, and the medicine should be stopped immediately while seeking the doctor's help.

The seventh category is hematopoietic reaction, mainly manifesting as leukopenia, agranulocytosis, hemolytic anemia, aplastic anemia, purpura, and even death. This reaction resembles the toxicity of chemotherapy drugs. Chinese herbs such as Hongdoushan (yew), Sanjieshan (cephalotaxus), and Xishugu (camptotheca fruit) easily cause corresponding reactions.

For many years I have habitually had patients take medicine for a week and then stop for a week, or take it for three to five days and stop for three to five days, to avoid poisoning from herbs and patent medicines and raise the safety margin of clinical dosing. Generally, if the herb or patent medicine is effective against the patient's tumor and the patient is doing well, taking one week on and one week off will not delay treatment.

Over these years, most of my patients follow this instruction; in fact, such patients' survival has turned out longer, while those eager for quick results often die early because they cannot withstand the strong side effects.

In addition, during medication the patient should regularly recheck liver and kidney function and blood count, and feed the relevant data back to the prescribing doctor in time.

I have known some doctors who use poison; none use it for long all year. Some use it for three months a year, some for five or six, and few use it year-round. Long-term use of poison: the patient will not die of cancer but of the poison.

Patients also need to be "smart patients": do not blindly keep taking medicine; when feeling unwell or developing side effects, know when to stop, stop the medicine in time, and seek the doctor's help. Some patients, in their desperation, take a prescription nonstop for a whole year, until the liver, kidneys, and stomach are all injured and they cannot even eat—which is a great pity.

I have seen some cancer patients who, when critically ill and desperate to live, irrationally and self-administered large doses of highly toxic herbs or patent medicines, and mostly died rapidly.

If the side effects of poison-attacking-poison drugs are not well controlled and used to excess, they become poison rather than medicine, doing more harm than good. Both doctors and patients must have a clear understanding of this.

Only when both doctor and patient act rationally—neither fearing the drug for its toxicity nor blindly using it beyond the body's capacity in eagerness for results—can the efficacy of the poison be brought to its fullest, guarding the patient's life and health to the greatest extent.