A contraindication (pronounced as contra-indication) is a condition or factor that speaks against a certain measure. It is mostly used in medicine, with regard to factors that increase the risks involved in using a particular drug, carrying out a medical procedure, or engaging in a particular activity. Some contraindications are absolute, meaning that there are no reasonable circumstances for undertaking a course of action. For example, a baby with a fever should never be given aspirin because of the risk of Reye's syndrome, and a person with an anaphylactic food allergy should never eat the food to which they are allergic. Similarly, a person with hemochromatosis should not be administered iron preparations. Other contraindications are relative, meaning that the patient is at higher risk of complications, but that these risks may be outweighed by other considerations or mitigated by other measures. For example, a pregnant woman should normally avoid getting X-rays, but the risk may be far less than the risk of not diagnosing or being able to treat a serious condition such as tuberculosis or a broken bone. Relative contraindications may also be referred to as cautions, such as in the British National Formulary.

In medicine, most medications can be safely used with other medicines, but particular combinations of medicines need to be monitored for interactions, often by the pharmacist. In molecular biology, the knowledge on gene/protein interaction among themselves and with their metabolites is referred to as molecular pathways. Interactions between medications (drug interactions) fall generally into one of two main categories: 1. pharmacodynamic : Involving the actions of the two interacting drugs. 2. pharmacokinetic : Involving the absorption, distribution, metabolism, and excretion of one or both of the interacting drugs upon the other. In terms of efficacy, there can be three types of interactions between medications: additive, synergistic, and antagonistic. Additive interaction means the effect of two chemicals is equal to the sum of the effect of the two chemicals taken separately. This is usually due to the two chemicals acting on the body in the same way. Examples would be Aspirin and Motrin, Alcohol and Depressant, Tranquilizer and Painkiller. Synergistic interaction means that the effect of two chemicals taken together is greater than the sum of their separate effect at the same doses. An example is Pesticide and Fertilizer, the biological effect is devastating. Antagonistic interaction means that the effect of two chemicals is actually less than the sum of the effect of the two drugs taken independently of each other. This is because the second chemical increases the excretion of the first, or even directly blocks its toxic actions. Antagonism forms the basis for antidotes of poisonings.

list of symbols used on the package/label and their explanation

In United States safety standards, precautionary statements are sentences providing information on potential hazards, and proper procedures. They are used in situations from consumer product on labels and manuals, to descriptions of physical activities. Various methods are used to bring focus to them, such as setting apart from normal text, graphic icons, changes in text's font and color. Texts will often clarify the types of statements and their meanings within the text. Common precautionary statements are described below.

In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect, and may result from an unsuitable or incorrect dosage or procedure, which could be due to medical error. Adverse effects are sometimes referred to as "iatrogenic" because they are generated by a physician/treatment. Some adverse effects only occur only when starting, increasing or discontinuing a treatment. Using a drug or other medical intervention which is contraindicated may increase the risk of adverse effects. Adverse effects may cause medical complications of a disease or procedure and negatively affect its prognosis. They may also lead to non-compliance with a treatment regimen. The harmful outcome is usually indicated by some result such as morbidity, mortality, alteration in body weight, levels of enzymes, loss of function, or as a pathological change detected at the microscopic, macroscopic or physiological level. It may also be indicated by symptoms reported by a patient. Adverse effects may cause a reversible or irreversible change, including an increase or decrease in the susceptibility of the individual to other chemicals, foods, or procedures, such as drug interactions. In clinical trials, a distinction is made between adverse events (AEs) and serious adverse events (SAEs). Generally, any event which causes death, permanent damage, birth defects, or requires hospitalization is considered an SAE.[1] The results of these trials are often included in the labeling of the medication to provide information both for patients and the prescribing physicians.

complications that may arise following surgery

Packaging is the science, art and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of design, evaluation, and production of packages. Packaging can be described as a coordinated system of preparing goods for transport, warehousing, logistics, sale, and end use. Packaging contains, protects, preserves, transports, informs, and sells.[1] In many countries it is fully integrated into government, business, institutional, industrial, and personal use.