Histamine H2 Antagonist (Injection, Intravenous, Oral)

Overview

Histamine H2-receptor antagonists are prescribed to provide relief for acid reflux, gastroesophageal reflux disease, or to treat stomach, duodenal, or peptic ulcers. This medication is also intended to prevent the return of these diseases. Histamine H2-receptor antagonists are helpful for conditions where the stomach produces an excessive amount of acid.

These medications are available in strengths for over-the-counter sale as well. These drugs prevent and/or provide relief for sour stomach, acid indigestion, and heartburn. These medications can also be used for other types of conditions as your physician determines suitable.

H2-blockers can be obtained with a prescription from your physician and also can be purchased over-the-counter.

There are various types of H2 blockers, and most kinds are as effective as others. Side effects can vary though from one drug to another.

  • Famotidine (Pepcid Oral, Pepcid AC)
  • Cimetidine (Tagamet HB, Tagamet)
  • Ranitidine (Zantac Syrup, Zantac injection, Zantac Efferdose, Zantac 75, and Zantac)
  • Nizatidine capsules (Nizatidine Capsules, Axid Capsules, Axid AR)

This medication can be obtained in the dosing forms below:

  • Tablet, Effervescent
  • Tablet, Disintegrating
  • Tablet, Chewable
  • Tablet
  • Syrup
  • Suspension
  • Solution
  • Powder for Suspension
  • Powder for Solution
  • Packet
  • Injectable
  • Granule
  • Capsule, Liquid Filled
  • Capsule

Medication Brand Names (United States):

  • Pepcid AC
  • Pepcid
  • Heartburn Relief
  • Zantac 25
  • Zantac 150 Efferdose
  • Zantac 150
  • Zantac
  • Tagamet HB
  • Tagamet
  • Axid Pulvules
  • Axid AR
  • Axid

Medication Brand Names (Canadian):

  • Famotidine
  • Apo-Famotidine
  • Apo-Cimetidine
  • Alti-Ranitidine

Condition treated

  • Stomach acid
  • Acid reflux
  • Gastroesophageal reflux disease

Type of medicine

  • Histamine H2-receptor antagonists

Side Effects

In addition to benefits many medications provide, prescription drugs can occasionally also trigger side effects that can be undesirable. While it is not typically likely for each one of the side effects below to occur, they may necessitate medical care if they take place.

Consult with your physician right away if you experience one or more of the side effects below after taking a histamine blocker such as the h2 antagonist.

Rare Side Effects (Medical Care Required)

  • White spots, ulcers, or sores on genitals, lips, or in mouth
  • Wheezing
  • Weakness or tiredness (unusual)
  • Urine that is dark in color
  • Throat soreness
  • Swelling of the feet or hands
  • Swelling of the eyelids, tongue, mouth, lips, or face
  • Stools that are light in color
  • Stomach, abdominal, leg, or back pain
  • Slowness of heartbeat
  • Skin peeling
  • Skin or eyes yellowing
  • Redness, tenderness, burning, scaling, blistering of the skin
  • Painful or swollen glands
  • Painful or swollen glands
  • Pain
  • Overall feeling of illness or discomfort
  • Muscle aches or cramps
  • Mental or mood shifts, including mental illness, nervousness, mental depression, hallucinations (feeling, hearing, or seeing things not actually there), confusion, agitation, or anxiety
  • Loss of appetite, vomiting, or nausea
  • Joint pain
  • Itching or skin rash
  • Irregular, pounding, or quick heartbeat
  • Irregular or slow breathing (unusally)
  • Hives
  • Flu-like symptoms
  • Feet or hands swelling
  • Fainting
  • Eye irritation or redness
  • Dizziness
  • Difficulty coughing or swallowing
  • Crusting sores or bleeding on lips
  • Confusion
  • Chills and/or fever
  • Chest tightness
  • Chest tightness
  • Bruising or bleeding (unusual)
  • Breathing trouble
  • Breathing trouble
  • Breath shortness
  • Blurred vision or vision changes
  • Blood vessel inflammation
  • Blisters on feet soles or hand palms
  • Abrupt breathing difficulty

Occasionally, additional side effects may take place that typically do not require medical care. Your body will become more adjusted to the medication and these side effects will likely disappear over the course of treatment. In addition, your medical care professional can inform you of other methods of reducing or preventing side effects after taking the histamine h2 antagonist. Consult with your medical care professional if the side effects become troublesome, prolonged, or if you have concerns or questions regarding them.

Rare or Less Common Side Effects (Medical Care Not Typically Required)

  • Constipation
  • Reduced sexual desire
  • Reduced ability sexually (specifically for patients who have Zollinger-Ellison disease who have had doses of cimetidine that were high for a time period of one year)
  • Diarrhea
  • Urination difficulty
  • Dizziness
  • Drowsiness
  • Dryness of skin or mouth
  • Headache
  • Decrease or increase in urination
  • Hair loss
  • Sweating increase
  • Buzzing or ringing in ears
  • Runny nose
  • Breast swelling or soreness (females and males)
  • Difficulty sleeping

The side effects listed above have not been reported for every medication, but have been identified for at least one of the histamine H2 antagonist. The H2-blockers are all similar in chemical composition, so the side effects listed above could take place for any of the histamine H2 antagonist medications.

Additional side effects not included here may also take place for some patients. If other side effects are noticed, consult with your medical care professional.

Contact your physician for medical inquiries regarding side effects. The FDA also accepts reports of side effects, and they can be reached by calling 1-800-FDA-1088.

Dosage

Patients with unique medical circumstances will receive different doses of the medications in this class. Always follow the instructions given by your doctor or the medication label instructions. The information listed here provides an overview of only the typical doses of these medications. If you were prescribed a dose that varies from the information listed here, do not adjust your dose unless instructed by your physician.

The strength of the medication will also determine how much of the drug you are prescribed. In addition, the quantity of doses prescribed per day, the allotted time between one dose to another, and the total duration of time for which the medication is taken depends directly on the medical reason for why you need this medication.

For treatment of sour stomach, acid indigestion, and heartburn (nonprescription strengths):

  • The maximum dosage recommended for daily use should not be taken for a time period longer than two weeks, unless otherwise directed by your physician.
  • If you experience obstinate abdominal pain or difficulty swallowing, please see your physician right away. These could be symptoms of a severe condition that could require a different course of treatment.

For treatment of serious medical issues (prescription strengths):

  • One dose prescribed per day 'Take the dose at bedtime, unless directed otherwise by your physician.
  • Two doses prescribed daily'Take one dose right when you wake up (morning) and one before going to bed.
  • Several doses prescribed each day'For optimal results, doses should be taken with meals and at bedtime.

It could potentially take several days of taking this medication prior to you actually feeling the stomach pain relief this medication delivers. To aid in relieving stomach pain, antacids can be taken at the same time as the H2-blocker, unless your physician has recommended otherwise. However, you should wait a period of 30-minutes to one hour prior to taking the H2-blocker and the antacid.

Be sure to take this medication for the entire course of treatment, even if you find yourself feeling better before the course of treatment has ended. It is also highly important to keep check-up appointments with your physician so that your physician can let you know when you should stop taking the H2-blocker.

Famotidine tablets (chewable)

  • Chew tablet completely prior to swallowing.

Famotidine tablets (disintegrating, oral)

  • Ensure hands are completely dry.
  • Allow tablets to remain in the package (unopened) until you are ready to use them, then proceed to open the package and take out the tablet.
  • Put the tablet on your tongue right away.
  • The tablet will become completely dissolved in a matter of seconds, and it is then alright to be swallowed.
  • The tablet does not need to be swallowed with water or other drinks.

Ranitidine tablets (effervescent)

  • Never swallow the tablet whole, allow the tablet to dissolve on tongue, or chew the tablet.
  • The foil wrapping should be removed and the tablet (150 mg) should be dissolved in a 6-8 ounce glass of water prior to drinking.
  • Children and infants: Dissolve the medication (25 mg) tablet in 1 teaspoon of water and place in a cup intended for dosing. Ensure the tablet is dissolved completely prior to giving the medication to the child or infant.
  • The medication may be given to your child by oral syringe or dropper. Consult with your physician if you are not certain about the quantity of medication to give to your child.

Cimetidine

Oral dosage information (tablets and solution)

For treatment of gastric or duodenal ulcers

  • Geriatric patients, adults, and adolescents: Take 300 mg four times daily, along with each meal and just before bedtime. Some patients are directed to take 400 mg or 600 mg twice daily, in the morning and before bed. Other patients are instructed to only take 800 once daily before bedtime.
  • Children: Young people may take between 20 to 40 mg for each kg (or 9.1 mg to 18.2 mg per pound) of body weight. This amount should be taken in four separate doses, at bedtime and with meals.

For treatment of duodenal ulcers

  • Geriatric patients, adults, and adolescents: Patients should take a dosage amount of 300 mg twice daily, right when they wake up in the morning and right before bed. Other patients may be prescribed one dose of 400 mg before bed.
  • Children: Physician should determine dosage information.

For treatment of sour stomach, acid indigestion, or heartburn

  • Adults and adolescents: Take 100 mg to 200 mg of medication with a glass of water upon the onset of symptoms. This dose can be repeated one time in a period of 24 hours. Never take an amount greater than 400 mg in a single day.
  • Children: See your doctor for specific dosing guidelines.

For prevention of sour stomach, acid indigestion, and heartburn

  • Adults and adolescents: Take 100 mg to 200 mg of medication with a glass of water no more than an hour prior to drinking or eating if the food could trigger symptoms. Never take a dosage amount greater than 400 mg in a 24-hour period.
  • Children: Physician should determine dosage information based on the unique needs of the patient.

For treatment of excessive acidity in the stomach

  • Adults: Take 300 mg up to four times per day, along with mealtime and before bed. Your physician may wish to alter the dose if required.
  • Children: Your doctor should prescribe a dose suitable to your child's needs.

For treatment of gastroesophageal reflux disease

  • Adults: Take 800 mg to 1600 mg daily total, separated into doses that are smaller. The treatment period for gastroesophageal reflux disease is 12 weeks.
  • Children: Physician must calculate dosing requirements based on patient's needs.

Injection dosage information

For treatment of gastric ulcers, duodenal ulcers, or medical issues that cause excessive acidity in the stomach

  • Geriatric patients, adults, and adolescents: 300 mg of medication should be injected into the patient's muscle one time for every 6-8 hour period. Alternately, 300 mg of medication should be injected into a vein slowly one time every 6 to 8 hours. Another option is for 900 mg of medication to be injected into the patient's vein constantly around the clock; under these circumstances, 37.5 mg should be injected per hour. Certain patients could require 150 mg initially, prior to starting around-the-clock injections.
  • Children: For each kg of body weight (2.3 ' 4.5 mg/pound), 5 to 10 mg should be injected into either a muscle or vein, one time for each period of 6-8 hours.

For prevention of bleeding that is related to stress

  • Geriatric patients, adults, and adolescents: A medical professional should slowly inject 50 milligrams once per hour into a vein. This should be done around the clock for a period of no more than seven days.
  • Children: Physician must determine dosage requirements for unique patient needs.

Famotidine dosage information

Oral dosage information (tablets, suspension, oral disintegrating tablets, and chewable tablets)

For treatment of duodenal ulcers

  • Elderly adults, adults, and adolescents: Take 40 mg one time daily, just before bedtime. Certain patients may take 20 milligrams twice per day with permission from their doctor.
  • Children: Physician should always calculate dosage requirements for children.

For prevention of duodenal ulcers

  • Geriatric patients, adults, and adolescents: Take 20 milligrams once daily before bed.
  • Children: Physician must determine dose.

For treatment of gastric ulcers

  • Elderly adults, adults, and adolescents: Take 40 milligrams once daily right before bed.
  • Children: Physician should calculate the dosage information.

For treatment of sour stomach, acid indigestion, or heartburn

  • Adults and adolescents: Take 10 milligrams along with a glass of water upon the onset of symptoms. If needed, the patient may repeat the dose one time in a 24-hour period. Never take an amount greater than 20 mg in a 24-hour time period.
  • Children: Your doctor will be able to determine the dosage information for children.

For prevention of sour stomach, acid indigestion, or heartburn

  • Adults and adolescents: Take 10 milligrams an hour prior to eating any type of meal that could trigger symptoms. If needed, the dose can be repeated one time for every 24-hour time period. Patients should not take an amount greater than 20 milligrams in a single day.
  • Children: Physician should calculate dose.

For treatment of excessive production of acidity by the stomach

  • Elderly adults, adults, and adolescents: 20 milligrams should be taken once for each 6 hour time period. Your physician may adjust your dose if required.
  • Children: Your doctor must be the one to determine the dose for a child.

For treatment of gastroesophageal reflux disease

  • Geriatric patients, adults, and adolescents: Take 20 milligrams twice daily, typically for around 6 weeks (no longer than 6 weeks).
  • Children who weigh more than 22 pounds (10 kg): Parents or caregivers can give children 1-2 milligrams per kilogram of body weight per day (0.5 to 0.9 mg for every pound) in separate doses (typically two doses).
  • Children who weigh less than 22 pounds (10 kg): Parents or caregivers can administer a dose of 1-2 milligrams for every kilogram of body weight (0.5 '0.9 milligrams for every pound) each day (usually divided into three doses).

Injection dosage information

For treatment of gastric ulcers, duodenal ulcers, or other conditions of excessive stomach acid

  • Geriatric adults, adults, and adolescents: A medical care professional will inject 20 milligrams into your vein once every 12 hours.
  • Children: Doctor will determine unique dosage requirements based on the situation of the patient.

Nizatidine dosage information

Oral dosage information (oral solution and capsules)

For treatment of gastric or duodenal ulcers

  • Elderly patients, adults, and adolescents: Take 300 mg one time every day before going to bed. Some patients may be prescribed 150 milligrams twice daily.
  • Children: Your physician must calculate dosage information for a child.

For prevention of duodenal ulcers

  • Adults and adolescents: Take 150 milligrams once daily before bedtime.
  • Children: Your doctor can inform you of appropriate doses for children.

For prevention of sour stomach, acid indigestion, or heartburn

  • Adults and adolescents: Patients should take 75 milligrams 30-60 minutes prior to eating any type of meal that would likely trigger symptoms. Repeat the dose as needed one time per day.
  • Children: Physician must establish dose based on unique needs of the patient.

For treatment of gastroesophageal reflux disease

  • Adults and adolescents: Take 150 milligrams two times every day.
  • Children: The child's primary care physician should determine dose.

Ranitidine dosage information

Oral dosage information (tablets, syrup, and effervescent tablets)

For treatment of ulcers (duodenal ulcers)

  • Geriatric adults, adults, and adolescents: Take 150 mg twice daily. Some patients can take a dose of 300 milligrams one time per day before bed.
  • Infants and children: Parents and caregivers may give the child 2-4 milligrams for every kilogram of body weight (1-2 mg for every pound) twice every day. However, the entire dose should not exceed 300 milligrams daily.

To maintain or promote healing of duodenal ulcers

  • Elderly adults, adults, and adolescents: One dose (150 milligrams) before bedtime is typical.
  • Infants and children: Typical doses for young people are 2-4 milligrams for every kilogram (1-2 milligrams for every pound) of weight one time daily. The total daily dosage should not exceed 150 mg.

For treatment of erosive esophagitis

  • Geriatric patients, adults, and adolescents: Take 150 milligrams four times per day
  • Infants and children: Caregivers and parents should ensure that children take 5-10 milligrams per kilogram (2.3-4.6 milligrams for every pound) of body weight daily, typically divided between two doses throughout the day.

For treatment of erosive esophagitis

  • Elderly patients, adults, and adolescents: Patients in these age ranges should take 150 mg two times per day.
  • Infants and children: Physician must determine dose based on unique needs of the patient.

For treatment of gastric ulcers (benign)

  • Geriatric adults, adults, and adolescents: The typical recommended dose for these age groups is 150 milligrams twice daily.
  • Infants and children: Parents and caregivers may administer 2-4 milligrams per kilogram (1-2 milligrams for every pound) two times each day. Ensure the entire dose for the day does not exceed 300 milligrams daily.

For treatment of sour stomach, acid indigestion, or heartburn

  • Elderly patients, adults, and adolescents: Right when symptoms begin, take 150 milligrams with a glass of water. Repeat dose one time (within a 24-hour period), if required. Never take a dose greater than 300 milligrams within a 24-hour period.
  • Children: Your child's physician must calculate the dose.

Injection dosage information

For treatment of gastric ulcers, duodenal ulcers, or other conditions of excessive acid within the stomach

  • Geriatric patients, adults, and adolescents: Your medical professional should inject 50 mg of medication into one of your muscles one time every 6-8 hours. Alternately, 50 milligrams may be slowly injected into one of your veins once every 6-8 hours. A third option is to have 6.25 milligrams every hour slowly injected into one of your veins 24 hours a day. The majority of patients will not require doses greater than 400 milligrams per day, however.

For treatment of gastric or duodenal ulcers

  • Children: Medical professionals should inject 2-4 milligrams per kilograms of body weight each day (1-2 milligrams per pound) into a vein. This dose should be divided into smaller doses and should be slowly injected once every 6-8 hours. The total dosage amount should never be greater than 50 milligrams once for each 6-8 hour period.

Missed Dose

Missed doses of this medication must be taken right away. However, if it is nearer in the dosage schedule to the next dose, you may allow the skipped dose to remain missed and you may return to the original dosing schedule. Never double dose on this medication.

Interactions

Drug Interactions

While it is not typically recommended for certain medications to be combined, unique circumstances may warrant the combination despite the possibility of interaction. Under these circumstances, your physician may be inclined to adjust the dose, or they may take other precautions for your safety.

It is highly important that you inform your medical professional if you are taking any of the medications listed below while on an H2 antagonist. The interactions listed below were chosen due to their possible significance. The list below is not all-inclusive.

It is not typically suggested to take medications in the H2 antagonist class with the medications below. Your physician may adjust the other medications you may be taking or they may choose not to prescribe an H2 antagonist.

  • Ziprasidone
  • Thioridazine
  • Terfenadine
  • Sparfloxacin
  • Saquinavir
  • Piperaquine
  • Pimozide
  • Mesoridazine
  • Dronedarone
  • Dofetilide
  • Cisapride
  • Bepridil
  • Amisulpride
  • Amifampridine

It is not usually suggested to take medications in the H2 antagonist class with the medications below, but certain circumstances may require the combination. If both prescriptions are given at the same time, your physician may adjust the dosage or frequency for either one of both medications.

  • Zuclopenthixol
  • Zalcitabine
  • Vismodegib
  • Vinflunine
  • Vemurafenib
  • Vandetanib
  • Triptorelin
  • Tolazoline
  • Tizanidine
  • Theophylline
  • Tegafur
  • Tacrolimus
  • Sulpiride
  • Sotalol
  • Sevoflurane
  • Rilpivirine
  • Quetiapine
  • Posaconazole
  • Pitolisant
  • Piperaquine
  • Pimavanserin
  • Pazopanib
  • Pasireotide
  • Panobinostat
  • Oxymorphone
  • Ondansetron
  • Nafarelin
  • Moxifloxacin
  • Morphine Sulfate Liposome
  • Morphine
  • Metronidazole
  • Meperidine
  • Levofloxacin
  • Leuprolide
  • Ledipasvir
  • Ketoconazole
  • Ivabradine
  • Hydroxyzine
  • Hydroxychloroquine
  • Histrelin
  • Goserelin
  • Gonadorelin
  • Gefitinib
  • Fluoxetine
  • Fluorouracil
  • Escitalopram
  • Erlotinib
  • Eliglustat
  • Efavirenz
  • Doxifluridine
  • Donepezil
  • Domperidone
  • Deslorelin
  • Delavirdine
  • Delamanid
  • Degarelix
  • Dasatinib
  • Dabrafenib
  • Crizotinib
  • Clozapine
  • Clopidogrel
  • Clarithromycin
  • Citalopram
  • Chloroquine
  • Carmustine
  • Capecitabine
  • Buserelin
  • Bupropion
  • Atazanavir
  • Arsenic Trioxide
  • Aripiprazole
  • Anagrelide
  • Amiodarone
  • Alosetron

Other Interactions

Consult with your physician to find out if there are any types of food that you should avoid while taking this medication that could potentially aggravate stomach acidity. Also, the use of tobacco or alcohol in combination with certain types of prescription medications can trigger interactions to take place. Consult with your physician to find out how H2-receptors impact tobacco or alcohol use.

Medical Interactions

Patients with other medical issues could experience impacts in the effectiveness of this medication. Be sure that you inform your physician if you have other types of medical issues, specifically:

  • Porphyria (a rare genetic disease that impacts food digestion; take caution, conditions can be made worse for patients with acute porphyria)
  • Phenylketonuria (PKU; Certain types of H2-blockers have aspartame in the ingredients. The body converts aspartame to phenylalanine within the body and patients with PKU should take caution. Pepcid AC chewable tablets (famotidine) have 1.4 milligrams of phenylalanine within each 10-mg dose. Pepcid RPD oral dispersible pills (famotidine) have 1.05 mg of phenylalanine for every 20-milligram dose. Zantac efferdose (ranitidine) pills have 2.81 milligrams of phenylalanine for every 25-milligram dose and 16.84 milligrams of phenylalanine for every 150-milligram dose.
  • Liver disease (take caution; the H2-blocker could residually build up within the bloodstream, and this can cause side effects to increase)
  • Kidney disease
  • Immune system weakness (can create difficulty when the body needs to fight infection). Reduction of stomach acid caused by this medication could potentially raise the likelihood of a particular kind of infection.

Warnings

Certain medical tests could be impacted by this medication. Inform your physician that you are taking this prescription prior to having any skin tests to identify allergies, or before having tests to find out the amount of stomach acidity.

Some medications (including aspirin as well as some drinks and foods, including carbonated drinks or citrus products) can aggravate the stomach and can make issues worse.

Patients who smoke cigarettes may experience impacts in the effectiveness of H2-blockers due to the increase in acidity that the stomach produces. This is more likely to impact the acidity production of the stomach during the night. Patients should completely stop smoking cigarettes prior to taking H2-blockers, or they should at least not smoke a cigarette after the final dose of medication for the day.

The consumption of alcoholic beverages while on an H2-receptor antagonist can increase BAC levels (blood alcohol level). Always take caution when combining alcohol and an H2-receptor antagonist, and see your physician if you are seeking professional guidance.

Consult with your physician if ulcer pain becomes worse or continues.

Specific Demographic Use

Pediatric

This medication has proven to be safe and effective for children when dosed correctly. It should be used for short durations of time.

Geriatric

Elderly patients may experience dizziness and confusion when taking an H2-blocker because older people tend to be more sensitive to H2-blocker effects.

Pregnancy

It has not yet been studied whether or not H2-blockers are safe for pregnant women. Animal studies reveal that there are no harmful effects for ranitidine or famotidine. However, cimetidine has revealed that there could be potential issues for sexual development in males. Additional research is necessary to confirm these concerns for pregnant women. Research in rabbits with high doses revealed that com/health/miscarriage/">miscarriages or low birth weights can take place from taking nizatidine. Be sure to inform your physician if you are pregnant or plan on becoming pregnant while taking an H2-blocker.

Breastfeeding

Ranitidine, nizatidine, famotidine, and cimetidine can pass into breast milk and could trigger undesired side effects, including increased excretion of the medication into the milk and reduced quantities of stomach acid in breastmilk. You may need to switch to a different medication or discontinue breastfeeding while on this course of treatment.

Storage

This medication should be kept in a sealed container away from frozen or hot temperatures, as these can impact the chemical composition of the medication. Moisture and direct light should be avoided when storing this medication.

Always keep this medication far from the reach of young children.

Never keep medication that is no longer required or that is expired.

Summary

Histamine H2 antagonists stop histamine-caused gastric acid discharge from the parietal cells of the stomach lining. These medications treat gastrointestinal conditions (hypersecretory), gastrointestinal ulcers, and gastroesophageal reflux disease (GERD). These medicines are also often used for other kinds of conditions that the physician has found suitable. Histamine H2 antagonists are available in both injection and tablet forms and are suitable for patients of any age who need to control stomach acidity.