Can You Buy Cimetidine Over The Counter ((LINK))
Cimetidine is used to treat ulcers; gastroesophageal reflux disease (GERD), a condition in which backward flow of acid from the stomach causes heartburn and injury of the food pipe (esophagus); and conditions where the stomach produces too much acid, such as Zollinger-Ellison syndrome. Over-the-counter cimetidine is used to prevent and treat symptoms of heartburn associated with acid indigestion and sour stomach. Cimetidine is in a class of medications called H2 blockers. It decreases the amount of acid made in the stomach.
can you buy cimetidine over the counter
Cimetidine comes as a tablet and a liquid to take by mouth. It is usually taken once a day at bedtime or two to four times a day with meals and at bedtime. Over-the-counter cimetidine is usually taken once or twice a day with a glass of water. To prevent symptoms, it is taken within 30 minutes before eating or drinking foods that cause heartburn. Follow the directions on your prescription or the package label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take cimetidine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Do not take over-the-counter cimetidine for longer than 2 weeks unless your doctor tells you to. If symptoms of heartburn, acid indigestion, or sour stomach last longer than 2 weeks, stop taking cimetidine and call your doctor.
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Cimetidine is a drug with the indication of peptic ulcer disease, gastroesophageal reflux disease, and dermatological conditions including warts, urticaria, mastocytosis, and erythropoietic protoporphyria. This medication is an H2 receptor antagonist. This activity will describe cimetidine's indications, actions, and contraindications in these disorders. Cimetidine is available as an over-the-counter medication and by prescription. Therefore, this activity will further highlight the mechanisms of action, adverse effect profile, and other key factors pertinent to interprofessional team members in managing patients by using cimetidine.
Objectives:Identify the mechanism of action of cimetidine.Describe the indications for using cimetidine.Review the drug-drug interactions associated with cimetidine use.Outline the interprofessional team strategies regarding healthcare, coordination, and communication to improve the therapeutic outcome of cimetidine in patients who would benefit therapeutically.Access free multiple choice questions on this topic.
Cimetidine is a gastric acid reducer used in the short-term treatment of duodenal and gastric ulcers.[1] Therefore, the drug effectively manages gastric hypersecretion and is used to manage reflux esophagitis disease and prevent stress-related gastric ulcers. With the development of proton pump inhibitors, such as omeprazole, approved for the same indications, cimetidine is available as an over-the-counter formulation to prevent heartburn or acid indigestion, along with the other H2-receptor antagonists.
In the past, before the approval of proton pump inhibitors, intravenous cimetidine offered a treatment option to seriously ill patients in the intensive care unit who required prophylaxis against stress-induced ulcers through its H2-receptor antagonist.[2]
Recently, several studies have assessed the use of cimetidine in dermatology, including warts, ulceration, and mastocytosis. For example, treatment of multiple warts in pediatric heart transplant recipients.[3] In adults, cimetidine therapy appears to be beneficial with low toxicity in treating recalcitrant warts.[4] This effect may be due to reports of the immunomodulatory properties of this drug, attributed to cimetidine's ability to reduce regulatory/suppressor T cell-mediated immunosuppression.[5]
There are also reports that cimetidine can inhibit heme biosynthesis and results in symptomatic improvement in children with acute intermittent porphyria and porphyria cutanea tarda. Both conditions are related to erythropoietic protoporphyria, a rare hereditary disease of heme biosynthesis that manifests with severe photosensitivity and hepatotoxicity. The rapid reduction in photosensitivity was observable within weeks of initiating cimetidine systemic therapy, and skin photosensitivity also improved. Also, there was a reduction in serum erythrocyte protoporphyrin levels, and liver function tests improved with no adverse effects from cimetidine for over two years of treatment.[6] Similar results were reported with the use of cimetidine and lactulose.[7] However, other researchers reported that there is not enough evidence for the benefit of cimetidine in protoporphyria.[8][9]
Other studies support cimetidine as a treatment for bladder pain resulting from interstitial cystitis. There is no conclusion yet whether the mechanism involves a peptidergic pathway in the human bladder as cimetidine has on the parietal cells of the gastrointestinal tract.[16]
Understanding the physiology of gastric acid secretion is essential for understanding the mechanism of action of cimetidine. The primary stimuli for gastric acid secretion include (i) gastrin, released from antral G cells, (ii) histamine released from oxyntic enterochromaffin-like cells, and (iii) acetylcholine released from antral and oxyntic neurons secondary to parasympathetic (vagal) stimulation.[17] Other stimuli for gastric secretion include ghrelin and motilin. Acid release results from the stimulatory effect of histamine on parietal cells, which is mediated by adenylate cyclase activation and the generation of cyclic AMP (cAMP).[1] This cAMP activates a specific protein kinase, which phosphorylates a yet unknown substrate that propagates the stimulatory signal.[18]
The H2-receptor antagonist cimetidine competitively blocks histamine from stimulating the H2-receptors located on the gastric parietal cells (these cells are responsible for hydrochloric acid secretion and secretion of the intrinsic factor). The effect reduces the volume of gastric acid secretion from stimuli, including histamine, food, caffeine, and insulin.
Cimetidine is available as an oral tablet and solution. The drug can also be administered parenterally as an intravenous (IV) injection. The recommended dosage of cimetidine for the pediatric patient is 20 to 40 mg/kg/day administered in divided doses every 6 hours (5 to 10 mg for neonates and 10 to 20 mg for infants; both divided every 6 to 8 hours also). The recommended dosage for treating peptic ulcers in adults is 300 to 400 mg twice daily or 800 mg at bedtime for up to eight weeks. The maintenance dosage of cimetidine is 400 mg per day. Dosages of 200 to 400 mg (OTC formulations) per day can effectively manage or prevent heartburn caused by the intake of caffeine and certain foods. Thus, cimetidine is optimally administered thirty minutes before a meal.
High doses of cimetidine (over 5 g/day) can cause reversible impotence or gynecomastia.[20] This effect appears to result from the antiandrogenic potential of cimetidine, which depends on an increase in prolactin levels secondary to histamine H2 receptor blockade. Also, cimetidine has non-specific actions that stimulate prolactin secretion, causing galactorrhea in men in a dose-related pattern.[21][22] The effects could also be related to a blockade of the 2-hydroxylation of estradiol. However, gynecomastia in men is not an adverse effect with the other H2 receptor blockers (ranitidine, famotidine, and nizatidine).
Patients receiving treatment with drugs metabolized through the cytochrome P450 enzymatic pathway may experience enhanced drug effects resulting from pharmacokinetic interaction when treated concomitantly with cimetidine, as it is a well-known enzyme inhibitor of several CYP isoforms, including 1A2, 2C9, 2D6, 3A4 P450 isoforms. Clinically relevant is the inhibition of cytochrome 3A4 and 1A2.[20][23] Inhibition of these enzymes can lead to increased plasma levels of certain drugs, including warfarin, tricyclic antidepressants, lidocaine, calcium channel blockers, quinidine, oral sulfonylureas, phenytoin, theophylline, benzodiazepines, and beta-blockers (metoprolol and propranolol). For example, patients treated with warfarin sodium and cimetidine were found to have augmented hypoprothrombinemia and higher blood concentrations of warfarin. Such effects did not occur in patients treated with ranitidine and warfarin sodium. The effect is related to the inhibition of hepatic microsomal activity caused by cimetidine, which reduced the metabolic clearance of warfarin and augmented its anticoagulant effect.[24]
Impairment of vitamin B12 absorption raises the possibility that long-term, full-dose therapy with cimetidine may produce B12 deficiency similar to that observed in other hypochlorhydric states.[28] This effect is because parietal cells produce intrinsic factor necessary for vitamin B12 absorption. This effect is more common in younger female patients and will resolve with the discontinuation of cimetidine therapy.[28]
There is a low incidence of cimetidine-induced hepatitis, suggesting a hypersensitivity-type reaction.[29] Some reported central nervous system effects, such as headache, dizziness, delirium, drowsiness, and somnolence, can limit cimetidine's use in the geriatric population and patients with renal and hepatic disorders.[30] Therefore, monitoring renal function is critical in the elderly to avoid these neuropsychiatric effects. The adverse effects mentioned here, along with the availability of proton pump inhibitors approved for treating similar gastrointestinal conditions, have limited the use of cimetidine. 041b061a72