What Are the Different Uses of Cimetidine Tablets?

Cimetidine tablets are used to treat duodenal ulcers, gastric ulcers, reflux esophagitis, stress ulcers and Zollinger-Ellison syndrome.

Drug Name: Cimetidine
Drug type: Work Injury Medical Insurance Class A Double Span

Hanyu Pinyin: Xi Mi Ti Ding Pian
Use classification: Drugs that inhibit gastric acid secretion

Cimetidine tablets ingredients

The main ingredient of this product is cimetidine,
Its chemical name is: N1-methyl-N11- [2 [[(5-methyl-1H-imidazol-4-yl) methyl] thio] ethyl] -N-cyano arc.
Its structural formula is:

Molecular formula: C ₁₀ H ₁₆ N ₆ S
Molecular weight: 252.34

Cimetidine Tablet Properties

This product is a light green cystic film-coated tablet.

Cimetidine tablets indications

For the treatment of duodenal ulcer, gastric ulcer, reflux esophagitis, stress ulcer and Zollinger-Ellison syndrome.

Cimetidine tablets specifications

0.4g each

Cimetidine dosage and dosage

This medicine must be used as prescribed by a physician. adult:
(1) For treatment of duodenal ulcer or pathological hypersecretory state, 0.2g 0.4g once, 2-4 times a day, after meals and before bedtime, or 0.8g once, once before bedtime.
(2) To prevent recurrence of ulcers, 0.4g at a time, before bedtime;
(3) The dosage for patients with renal insufficiency is reduced to 0.2g once, once every 12 hours.
(4) Reduce the dosage of elderly patients.

Cimetidine adverse reactions

Adverse reactions to this product are generally uncommon and usually disappear after continued or discontinued medication.
1. The more common adverse reactions were diarrhea, fatigue, dizziness, drowsiness, headache, and rash.
2. This product has a mild anti-androgenic effect. When the dosage is large (above 1.6 g per day), it can cause male breast development, female galactorrhea, hyposexuality, impotence, and decreased sperm count. It disappears after stopping the drug.
3 This product can pass the blood-cerebrospinal fluid barrier and has certain neurotoxicity. Occasional mental disorders, anxiety, depression, anxiety, delirium, hallucinations, and disorientation are more common in elderly and severely ill patients, and symptoms generally disappear 3-4 days after drug withdrawal. In the treatment of gastrointestinal comorbidities of alcoholics, tremor delirium may occur, similar to alcohol withdrawal syndrome;
4 Rare side effects of this product are: allergic reactions, fever, joint pain, myalgia, interstitial nephritis, urinary retention, liver toxicity, pancreatitis.
5. Very few patients have leukocytopenia and agranulocytosis. These people suffer from other serious conditions and receive drugs and treatments known to reduce blood cells. Thrombocytopenia and aplastic anemia are rarely reported. Occasionally, plasma creatinine or serum aminotransferase increases. Very rare hepatitis.
6. Bradycardia, tachycardia and heart block, and allergic vasculitis have been reported very rarely with H ₂ receptor blockers. All of these reactions usually disappear after discontinuation.

Cimetidine tablets contraindications

Those who are allergic to this product are prohibited.

Precautions for cimetidine

1. For cancerous ulcers, a clear diagnosis should be made before use to avoid delay in treatment.
2. Elderly patients, due to impaired renal function, slow down the elimination of this product, which can lead to an increase in blood concentration, and therefore are more prone to toxic reactions and symptoms of dizziness and delirium.
3. If you have a history of drug allergy, please follow your doctor's advice.
4 Diagnostic interference: a false positive in gastric occult blood test within 15 minutes of oral administration; blood salicylic acid concentration, serum creatinine, prolactin, aminotransferase and other concentrations may all increase;
5. To avoid nephrotoxicity, check renal function during medication.
6. This product has a certain inhibitory effect on the bone marrow. During the medication, pay attention to check the blood.
7. The neurotoxic symptoms of this product are very similar to those caused by central anticholinergics, and treatment with the pseudocholine drug physostigmine can improve the symptoms. Therefore, the simultaneous use of this product and central anticholinergics should be avoided to prevent aggravating central nervous system toxic reactions.
8. In elderly patients, patients with chronic lung disease, diabetes, and immunodeficiency patients, the risk of community-acquired pneumonia may increase with H2-receptor antagonists. A large epidemiological study showed that patients who are receiving H2-receptor antagonists have an increased risk of developing community-acquired pneumonia.
9. The following situations should be used with caution:
(1) Severe heart and respiratory diseases.
(2) In patients with systemic lupus erythematosus (SLE), the bone marrow toxicity of cimetidine may increase.
(3) Organic encephalopathy.
(4) Impaired liver and kidney function.
10. Keep this medicine out of the reach of children.

Cimetidine tablets for pregnant and lactating women

This product can pass through the placental barrier and can enter milk. It is prohibited for pregnant and lactating women.

Cimetidine tablets for children

Not recommended for children under 16 years.

Cimetidine tablets for elderly

Reduce the amount.

Cimetidine Drug Interactions

1. Combined with antacids, it has a synergistic effect on pain relief of duodenal ulcers, but the absorption of cimetidine may be reduced, so it is generally not recommended. If it must be combined with antacids, they should be taken at least 1 hour apart.
2. Metoclopramide (Metoclopramide) can be taken with this product at the same time, which can reduce the blood concentration of this product, and the dose of this product needs to be appropriately increased.
3 Since sucralfate needs to be hydrolyzed by gastric acid before it can function, this product inhibits gastric acid secretion. The combination of the two may reduce the efficacy of sucralfate.
4 This product inhibits the oxidative metabolism pathway catalyzed by cytochrome P450 and can reduce liver blood flow. Therefore, this product can reduce the metabolism of other drugs when used in combination with other drugs, resulting in enhanced pharmacological activity or toxicity. These drugs include:
(1) With long-term combination with benzodiazepines, intrahepatic metabolism can be inhibited, which leads to an increase in the blood concentration of the latter, aggravates sedation and other central nervous system inhibitory effects, and can develop into respiratory and circulatory failure. But among them, Laurazep, Osaxep, and Timothy pep seem to be unaffected.
(2) When combined with warfarin and other coumarin anticoagulants, the prothrombin time can be further extended, so it is necessary to pay close attention to changes in the condition and adjust the amount of anticoagulant medicine.
(3) The combination with phenytoin sodium or other hydantoin may increase the blood concentration of the latter, resulting in phenytoin poisoning. When it must be combined, the phenytoin blood concentration should be measured after 5 days in order to adjust the dose, and pay attention Periodic review of peripheral blood.
(4) When combined with propranolol, metoprolol, and metronidazole, the blood concentration may increase.
(5) When combined with xanthine drugs such as theophylline, caffeine, and aminophylline, liver metabolism decreases, which can lead to delayed clearance, an increase in blood concentration, and possible toxic reactions.
(6) This product can increase the absolute bioavailability of verapamil (Isodamine) from 26.3% ± 16.8% to 49.3% ± 23.6%. Because verapamil can have rare but serious side effects, therefore Attention should be given.
(7) This product can inhibit quinidine metabolism. When patients take digoxin and quinidine at the same time, it should not be used again. Because quinidine can replace digoxin from its binding site, the blood concentrations of quinidine and digoxin are increased. The blood drug concentration should be monitored at this time.
(8) It should be used with other intrahepatic metabolic drugs, such as lidocaine and tricyclic antidepressants.
5. In combination with opioids, adverse reactions such as respiratory depression, mental confusion, and loss of orientation have been reported in patients with chronic renal failure. For such patients, the amount of opioids should be reduced.
6. Because this product raises the pH of gastric juice, when used in combination with tetracycline, the dissolution rate of tetracycline can be reduced, absorption can be reduced, and the effect can be weakened (however, the enzyme inhibitory effect of this product may increase the blood concentration of tetracycline); The combination of aspirin has the opposite effect, which can enhance the effect of aspirin.
7. Combination with ketoconazole can interfere with the latter's absorption and reduce its antifungal activity, but the same changes can be avoided with some acid drinks.
8. The combination of this product with captopril may cause mental symptoms.
9. Because this product has a muscle nerve blocking effect similar to aminoglycoside antibiotics, this effect is not countered by neostigmine, but can only be countered by calcium chloride. Therefore, combination with aminoglycosides may cause respiratory depression or respiratory arrest.

Cimetidine overdose

Shortness of breath or dyspnea and tachycardia are common. Treatment: First remove the drugs that have not been absorbed in the gastrointestinal tract, and give clinical monitoring and supportive therapy. If respiratory failure occurs, artificial respiration is immediately performed. Those with tachycardia can be given -blockers.

Cimetidine Pharmacology and Toxicology

1. Pharmacology mainly acts on H ₂ receptors on gastric parietal cells, and plays a competitive role in inhibiting histamine. Can inhibit basal gastric acid secretion, but also inhibit gastric acid secretion stimulated by food, histamine, pentagastrin, caffeine, and insulin.
2. Toxicology Acute toxicity: The oral LD _{50 in} mice is 3190-3280mg / kg, and the oral LD ₅₀ in rats is 5840-7500mg / kg. Subacute and chronic toxicity tests in rats and dogs prove that this product has a mild anti-androgenic effect, which causes the weight of the prostate and seminal vesicles to decrease, milk secretion occurs, but disappears after stopping the drug. No mutagenic, carcinogenic, teratogenic effects, no dependence and drug resistance.

Pharmacokinetics of Cimetidine Tablets

After oral administration, about 60% to 70% are rapidly absorbed by the intestine, and the peak concentration time (tmax) of the blood drug is 45 to 90 minutes. Oral bioavailability (F) is about 70%. Young people tend to absorb this product better than older people. Low plasma protein binding. Taking 300mg average peak concentration (Cmax) is 1.44 g / ml, can inhibit basal gastric acid secretion by 50% for 4 to 5 hours. This product is widely distributed in whole body tissues (except the brain), is metabolized in the liver, and is mainly excreted by the kidneys. After 24 hours, about 48% of the oral dose was excreted from the kidney in the original form; 10% was excreted from the feces. This product can be removed by hemodialysis. When the renal function is normal, the half-life (t _1/2 ) is 2 hours, the creatinine clearance is 20-50ml / min, the half-life (t _1/2 ) is 2.9 hours, when <20ml / min is 3.7 hours, and when renal function is insufficiency For 5 hours. This product can be transported through the placenta and excreted from milk.

Storage of Cimetidine Tablets

Keep sealed.

Cimetidine Tablets Packaging

Aluminum plastic blister, 10 pieces per plate, 1 plate per box.
Aluminum-plastic blister, 10 pieces per plate, 2 plates per box.

Cimetidine

Three years

Cimetidine Tablets

"Chinese Pharmacopoeia" 2005 edition two

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