What are the functions, effects, and side effects of Analgin tablets?

Generally, the efficacy and functions of Metamizole Sodium Tablets include antipyretic effects, relieving headache, reducing joint pain, alleviating muscle pain, and easing dysmenorrhea. Possible side effects include gastrointestinal discomfort, allergic reactions, hematologic system abnormalities, collapse, and aplastic anemia. Detailed explanations are as follows:

I. Efficacy and Functions

1. Antipyretic Effect

Metamizole Sodium Tablets primarily achieve a strong antipyretic effect by inhibiting the synthesis and release of prostaglandins in the hypothalamic thermoregulatory center and restoring the normal responsiveness of thermoregulatory center neurons. Typically, body temperature gradually decreases about half an hour to one hour after administration and is commonly used for fever reduction in acute high fever conditions.

2. Relieving Headache

Metamizole Sodium Tablets can inhibit the transmission of pain nerve impulses, act on the central nervous system, and block the transmission of pain signals, thereby alleviating headache symptoms. Whether the headache is caused by a common cold or migraine, Metamizole can relieve the pain to some extent at appropriate doses, typically taking effect within 1-2 hours after administration.

3. Reducing Joint Pain

For joint pain caused by rheumatoid arthritis or other similar conditions, Metamizole Sodium Tablets can inhibit the release of inflammatory mediators, reduce local joint inflammation, and thereby alleviate symptoms such as joint pain and swelling, helping patients improve joint mobility and quality of life.

4. Alleviating Muscle Pain

Muscle soreness caused by excessive exercise or muscle strain can be effectively relieved by Metamizole Sodium Tablets through inhibiting the production and release of pain-inducing substances in the body, reducing the sensitivity of muscle nerve endings, thus effectively alleviating muscle pain and restoring muscles to a normal state. Symptoms generally begin to subside within several hours after administration.

5. Easing Dysmenorrhea

For dysmenorrhea caused by uterine smooth muscle contraction and ischemia-hypoxia during menstruation, Metamizole Sodium Tablets can inhibit excessive contraction of the uterine smooth muscle, reduce prostaglandin synthesis, relieve uterine spasms, and thereby reduce dysmenorrheal symptoms, enabling women to have a more comfortable menstrual period.

II. Side Effects

1. Gastrointestinal Discomfort

Metamizole Sodium Tablets directly irritate the gastrointestinal mucosa, increase gastric acid secretion, and consequently damage the gastrointestinal mucosa, often leading to symptoms such as nausea, vomiting, and abdominal pain. Long-term or excessive use may also cause peptic ulcers and gastrointestinal bleeding, significantly impairing normal digestive and absorptive functions of the gastrointestinal tract.

2. Allergic Reactions

In some patients, the immune system may recognize Metamizole Sodium Tablets as foreign antigens, triggering an immune response and releasing inflammatory mediators such as histamine, leading to allergic symptoms such as skin rashes, itching, and erythema. Severe cases may even cause respiratory allergies, such as asthma attacks.

3. Hematologic System Abnormalities

Metamizole Sodium Tablets may suppress bone marrow hematopoietic function, interfere with the proliferation and differentiation of hematopoietic stem cells, leading to reduced white blood cell and platelet counts. Severe cases may result in agranulocytosis. This occurs because the drug affects the microenvironment of blood cell production in the bone marrow, hindering the normal development and maturation of blood cells.

4. Collapse

During rapid fever reduction through heavy sweating, if fluids and electrolytes are not promptly replenished, the patient's blood volume may sharply decrease, leading to collapse. This is caused by a large loss of body fluids in a short time without timely replenishment, resulting in internal environmental disturbances.

5. Aplastic Anemia

Long-term or excessive use of Metamizole Sodium Tablets may cause irreversible damage to bone marrow hematopoietic stem cells, preventing their normal differentiation and proliferation, leading to pancytopenia and causing aplastic anemia. Although this side effect is rare, once it occurs, the condition is severe and difficult to treat.

In daily use, it is recommended to strictly follow medical instructions when using Metamizole Sodium Tablets; do not adjust the dosage or frequency of administration on your own. Before use, clearly inform your physician about any personal history of allergies or diseases. Closely monitor your body's response during medication. If any adverse symptoms occur, such as rashes, abdominal pain, or fatigue, stop taking the medication immediately and seek medical attention promptly so that the physician can assess the situation and take appropriate measures.