Drugs in the "adverse reactions"?

For the average person, the first reaction to see the drug instruction may be to pay attention to the "adverse reactions" column, because the use of drugs such as dosage or contraindications has long been doctors, and indications and pharmacological poisons difficult for ordinary people to understand The reason is not within the understanding of the patient. However, after seeing the “adverse reactions” column, many patients have questions about “why the side effects of this drug are so large” and “can cause such horrible side effects that they should not be taken”. In fact, most of these doubts stem from misinterpretations of adverse drug reactions. Let's take a look at this article to find out how drug adverse reactions should be treated.

Sources of adverse reaction data

Most people will take it for granted that the "adverse reactions" in the drug labeling indicate the harmful effects that this drug can cause. However, from the collection process of adverse reaction data, this idea is not true. Because a drug can be written in the description of "adverse reactions", the cause of the induction is likely to have nothing to do with the drug and even the disease it is treating. It may even be due to some kind of cry and laughter.

In general, the collection of adverse drug reactions mainly stems from phase I-III clinical trials before the drug is marketed (for drug clinical trials, see the previous article “Why some “life-saving drugs” have not been approved”). Among them, phase I trials mainly collect important safety information of the drug (such as whether there are major side effects or the symptoms that patients are intolerable, the influence of the drug on the basic life index or vital organ activities, etc.), while the phase II and phase III trials Will collect more comprehensive information on adverse reactions.

In clinical trials, there is a major principle: whether in the trial group patients taking the new drug or the control group patients taking the old drug or placebo, as long as some kind of physical discomfort or symptoms occur after taking the drug, it needs to be used as an "adverse reaction" "It was recorded by the tester, regardless of the relevance of this symptom to the drug. This principle is mainly to avoid missing any possible adverse reactions, but it will also collect a large number of indiscriminate information that is not related to the drug. The two most common situations are: Drugs targeting a certain disease often collect adverse reactions that are consistent with the symptoms of the disease itself (for example, drugs that treat AIDS have “upper respiratory tract infection” adverse reactions, but in fact The patient itself is particularly prone to the disease; and some of the less frequent adverse events are caused by the patient's own factors (such as the appearance of "breast cancer" in the adverse reactions of analgesics). A patient in the trial group got breast cancer, which was not related to the drug.)

As for the "post-marketing experience" of adverse drug reactions, the source of data is even more confusing. A considerable number of countries have already established a nationwide reporting system for adverse drug reactions. Any suspicious adverse reactions that occur after taking drugs can be reported to the drug regulatory authorities. According to this information, the authorities then recommend that drug manufacturers modify the instructions and thus constitute The "post-marketing experience" section in the description. However, in general, because this system does not actively screen the patient for adverse reactions and drug-related interactions, the case-level adverse reactions it incorporates tend to be weaker than those in clinical trials.

The frequency of adverse drug reactions

In order to circumvent the occurrence of various contingencies and also to measure the severity and prevalence of adverse drug reactions, various adverse reactions will be carefully categorized according to frequency in the general drug instructions. The frequency classification of most drugs is as follows:

It is very common: the incidence of adverse reactions is more than 10%. Generally, the incidence of such adverse reactions during treatment is very high, and the correlation with drugs is often higher.

Common: refers to the incidence of adverse reactions> 1% and <10%, the frequency of such adverse reactions and the correlation with the drug is slightly lower than the "very common";

Rarely (sometimes called “uncommon”): The incidence of adverse reactions is more than 0.1% and less than 1%. The incidence of such adverse reactions is not high, but the number of people taking this drug is huge (if the drug is used In the treatment of common diseases such as flu and high blood pressure, there are still many patients who are actually “inviting”;

Rare: It means that the incidence of adverse reactions is more than 0.01% and <0.1% (also defined in the drug label as <0.1%). Such adverse reactions rarely occur, and the correlation with drugs is weak.

Very rare: The incidence of adverse reactions is less than 0.01%, and includes some case reports. The correlation between such adverse reactions and drugs is very weak, and the incidence is very low, but there are also some “very rare” defects. The reaction was indeed a serious adverse drug reaction.

How to treat the adverse reactions of drugs?

According to the above description, it is not difficult to know that the “adverse reactions” described in the drug descriptions are similar to the adverse reactions that may occur in real situations and there are various differences. How do you view this in the daily medical treatment? Problems? Here are some tips to consider:

☆To look at the data rationally, it is not always relevant to clearly understand the adverse reaction data and the actual adverse reactions. Do not expand the influence of “rare” or “very rare” adverse reactions described in the description, and do not report any adverse effects. React lightly;

☆For some adverse reactions with “very common” or “common” frequencies, you should be vigilant. If there are any, you should contact the attending physician as soon as possible to do the appropriate treatment, because some common adverse reactions to drugs may have serious consequences, or need The doctor adjusts the dose of the drug;

☆ If any drug-related adverse reactions occur during medication, report to the drug manufacturer or the drug regulatory agency if possible. Many large drug companies have established a hotline for reporting adverse drug reactions, and can also report to the next visit. Doctor instructions.