Famotidine 40mg/5ml Oral Susp 50ml
It is used to treat or prevent GI (gastrointestinal) ulcers.It is used to treat gastroesophageal reflux disease (GERD; acid reflux). It is used to treat heartburn and sour stomach.It is used to treat syndromes caused by lots of stomach acid.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antiulcer agent
Pharmacologic Class
Histamine H2-receptor antagonist
Pregnancy Category
Category B
FDA Approved
Oct 1986
DEA Schedule
Not Controlled
Overview
What is this medicine?
Famotidine is a medicine that reduces the amount of acid your stomach makes. It's used to treat and prevent heartburn, ulcers, and other conditions caused by too much stomach acid.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. However, before taking antacids with this medication, consult your doctor.
When using the liquid form, make sure to shake the bottle well before measuring your dose. Use the measuring device that comes with the medication to ensure accurate dosing. If a measuring device is not included, ask your pharmacist for one.
Storing and Disposing of Your Medication
Store this medication at room temperature in a dry place, avoiding bathrooms. Discard any unused portion after 1 month. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses. Since this medication is often taken as needed, do not take it more frequently than directed by your doctor.
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. However, before taking antacids with this medication, consult your doctor.
When using the liquid form, make sure to shake the bottle well before measuring your dose. Use the measuring device that comes with the medication to ensure accurate dosing. If a measuring device is not included, ask your pharmacist for one.
Storing and Disposing of Your Medication
Store this medication at room temperature in a dry place, avoiding bathrooms. Discard any unused portion after 1 month. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or take extra doses. Since this medication is often taken as needed, do not take it more frequently than directed by your doctor.
Lifestyle & Tips
- Avoid foods and drinks that trigger heartburn (e.g., spicy foods, fatty foods, caffeine, alcohol, citrus).
- Eat smaller, more frequent meals.
- Avoid eating close to bedtime (within 2-3 hours).
- Elevate the head of your bed if you experience nighttime heartburn.
- Quit smoking, as it can worsen acid reflux.
- Maintain a healthy weight.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
Varies by indication. For active duodenal ulcer: 40 mg once daily at bedtime or 20 mg twice daily. For GERD: 20 mg twice daily.
Dose Range:
10 - 160 mg
Condition-Specific Dosing:
Active Duodenal Ulcer:
40 mg once daily at bedtime or 20 mg twice daily for 4-8 weeks.
Maintenance Duodenal Ulcer:
20 mg once daily at bedtime.
Active Benign Gastric Ulcer:
40 mg once daily at bedtime for 6-8 weeks.
Gastroesophageal Reflux Disease (GERD):
20 mg twice daily for up to 6-12 weeks.
Erosive Esophagitis due to GERD:
20-40 mg twice daily for up to 12 weeks.
Pathological Hypersecretory Conditions (e.g., Zollinger-Ellison Syndrome):
20 mg every 6 hours; may be increased to 160 mg every 6 hours.
Pediatric Dosing
Neonatal:
Not established (limited data, generally avoided).
Infant:
0.5 mg/kg/dose once daily or divided twice daily (max 20 mg/day) for GERD/PUD. (For infants <3 months, 0.5 mg/kg once daily).
Child:
1-16 years: 0.5 mg/kg/dose twice daily (max 40 mg twice daily) for GERD/PUD.
Adolescent:
12-16 years: May follow adult dosing for specific indications, or 0.5 mg/kg/dose twice daily (max 40 mg twice daily).
Dose Adjustments
Renal Impairment:
Mild:
CrCl 50-80 mL/min: No adjustment typically needed.
Moderate:
CrCl 10-50 mL/min: Reduce dose by 50% or extend dosing interval to 36-48 hours.
Severe:
CrCl < 10 mL/min: Reduce dose by 50% or extend dosing interval to 36-48 hours.
Dialysis:
Administer dose after dialysis. Consider 50% dose reduction or extended interval.
Hepatic Impairment:
Mild:
No adjustment needed.
Moderate:
No adjustment needed.
Severe:
No adjustment needed.
Pharmacology
Mechanism of Action
Famotidine is a competitive inhibitor of histamine H2-receptors. It reversibly blocks the binding of histamine to H2-receptors on the gastric parietal cells, leading to a decrease in both basal and stimulated gastric acid secretion, as well as pepsin secretion.
Pharmacokinetics
Absorption:
Bioavailability:
40-45%
Tmax:
1-3 hours
FoodEffect:
Minimally affected by food; may slightly increase Tmax but not extent of absorption.
Distribution:
Vd:
0.96-1.3 L/kg
ProteinBinding:
15-20%
CnssPenetration:
Limited
Elimination:
HalfLife:
2.5-3.5 hours (prolonged to 11-13 hours in severe renal impairment)
Clearance:
Not available (primarily renal excretion)
ExcretionRoute:
Renal (glomerular filtration and tubular secretion)
Unchanged:
65-70% (of absorbed dose)
Pharmacodynamics
OnsetOfAction:
Within 1 hour
PeakEffect:
1-3 hours
DurationOfAction:
10-12 hours (single dose)
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. Immediately contact your doctor or seek medical attention if you experience any of the following symptoms, which may indicate a serious side effect:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Dizziness or fainting
Fast or abnormal heartbeat
Other Possible Side Effects
Like all medications, this drug can cause side effects. Although many people do not experience side effects or only have mild ones, it is essential to discuss any concerns with your doctor. Contact your doctor or seek medical help if you experience any of the following side effects or if they bother you or persist:
Headache
Note: This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch. Your doctor can provide medical advice about side effects and help you manage them.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. Immediately contact your doctor or seek medical attention if you experience any of the following symptoms, which may indicate a serious side effect:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Dizziness or fainting
Fast or abnormal heartbeat
Other Possible Side Effects
Like all medications, this drug can cause side effects. Although many people do not experience side effects or only have mild ones, it is essential to discuss any concerns with your doctor. Contact your doctor or seek medical help if you experience any of the following side effects or if they bother you or persist:
Headache
Note: This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch. Your doctor can provide medical advice about side effects and help you manage them.
Seek Immediate Medical Attention If You Experience:
- Severe or persistent stomach pain
- Difficulty swallowing
- Vomiting blood or material that looks like coffee grounds
- Black, tarry stools (signs of bleeding)
- Unexplained weight loss
- Chest pain (especially if accompanied by shortness of breath or pain radiating to arm/jaw - seek immediate medical attention as it could be heart-related)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
Certain health issues, including:
+ Black or bloody stools
+ Heartburn accompanied by lightheadedness, sweating, dizziness, or wheezing
+ Chest pain
+ Shoulder pain with shortness of breath
+ Pain that radiates to the arms, neck, or shoulders
+ Lightheadedness
+ Excessive sweating
+ Vomiting blood
+ Difficulty or pain when swallowing food
A history of heartburn that has lasted for 3 months or more
If you are currently taking any of the following medications: cefditoren, dasatinib, delavirdine, or fosamprenavir
Please note that this is not an exhaustive list of all potential interactions. It is crucial to discuss all of your medications (including prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist to ensure safe use. Do not initiate, discontinue, or modify the dosage of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
Certain health issues, including:
+ Black or bloody stools
+ Heartburn accompanied by lightheadedness, sweating, dizziness, or wheezing
+ Chest pain
+ Shoulder pain with shortness of breath
+ Pain that radiates to the arms, neck, or shoulders
+ Lightheadedness
+ Excessive sweating
+ Vomiting blood
+ Difficulty or pain when swallowing food
A history of heartburn that has lasted for 3 months or more
If you are currently taking any of the following medications: cefditoren, dasatinib, delavirdine, or fosamprenavir
Please note that this is not an exhaustive list of all potential interactions. It is crucial to discuss all of your medications (including prescription, over-the-counter, natural products, and vitamins) and health problems with your doctor and pharmacist to ensure safe use. Do not initiate, discontinue, or modify the dosage of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Adhere to the prescribed duration of treatment, and do not exceed the recommended timeframe without consulting your doctor.
If you have pre-existing kidney problems or are 65 years or older, discuss your condition with your doctor, as you may be at a higher risk of experiencing certain side effects. These potential side effects include hallucinations (seeing or hearing things that are not real), seizures, and feelings of agitation, confusion, sluggishness, or being out of sorts.
This medication may interfere with the absorption of other oral medications, reducing their effectiveness. If you take other medications by mouth, your doctor may advise you to take them at a different time than this medication to minimize potential interactions.
If you are pregnant, planning to become pregnant, or are breast-feeding, consult your doctor to discuss the potential benefits and risks of this medication to both you and your baby.
If you have pre-existing kidney problems or are 65 years or older, discuss your condition with your doctor, as you may be at a higher risk of experiencing certain side effects. These potential side effects include hallucinations (seeing or hearing things that are not real), seizures, and feelings of agitation, confusion, sluggishness, or being out of sorts.
This medication may interfere with the absorption of other oral medications, reducing their effectiveness. If you take other medications by mouth, your doctor may advise you to take them at a different time than this medication to minimize potential interactions.
If you are pregnant, planning to become pregnant, or are breast-feeding, consult your doctor to discuss the potential benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Restlessness
- Tachycardia (fast heart rate)
- Hypotension (low blood pressure)
- Flushing
- Dry mouth
What to Do:
Call 911 or Poison Control (1-800-222-1222) immediately. Treatment is generally symptomatic and supportive. Gastric lavage or activated charcoal may be considered if recent ingestion.
Drug Interactions
Major Interactions
- Cefditoren (decreased cefditoren absorption)
- Cefpodoxime (decreased cefpodoxime absorption)
- Dasatinib (decreased dasatinib absorption)
- Delavirdine (decreased delavirdine absorption)
- Erlotinib (decreased erlotinib absorption)
- Fosamprenavir (decreased fosamprenavir absorption)
- Iron salts (oral) (decreased iron absorption)
- Itraconazole (decreased itraconazole absorption)
- Ketoconazole (decreased ketoconazole absorption)
- Ledipasvir/Sofosbuvir (decreased ledipasvir/sofosbuvir absorption)
- Nilotinib (decreased nilotinib absorption)
- Pazopanib (decreased pazopanib absorption)
- Rilpivirine (decreased rilpivirine absorption)
- Sunitinib (decreased sunitinib absorption)
- Velpatasvir/Sofosbuvir (decreased velpatasvir/sofosbuvir absorption)
Moderate Interactions
- Antacids (decreased famotidine absorption - separate administration by 1-2 hours)
- Atazanavir (decreased atazanavir absorption)
- Dabigatran etexilate (increased dabigatran exposure)
- Mycophenolate mofetil (decreased mycophenolic acid exposure)
- Posaconazole (decreased posaconazole absorption)
Monitoring
Baseline Monitoring
Baseline symptoms of acid-related disorder
Rationale: To assess severity and guide treatment goals.
Timing: Prior to initiation of therapy
Renal function (CrCl)
Rationale: Famotidine is primarily renally eliminated; dose adjustment is necessary in renal impairment.
Timing: Prior to initiation of therapy, especially in elderly or those with suspected renal issues
Routine Monitoring
Symptom resolution/improvement
Frequency: Daily to weekly, depending on indication
Target: Significant reduction or complete resolution of heartburn, dyspepsia, pain.
Action Threshold: Lack of improvement after 1-2 weeks (OTC use) or completion of prescribed course (prescription use) warrants re-evaluation.
Adverse effects (e.g., headache, dizziness, GI upset)
Frequency: Routinely during therapy
Target: Absence or mild, tolerable effects.
Action Threshold: Persistent or severe adverse effects warrant dose adjustment or discontinuation.
Renal function (CrCl)
Frequency: Periodically in patients with pre-existing renal impairment or those at risk for developing it.
Target: Maintain appropriate CrCl for dosing.
Action Threshold: Significant decline in CrCl warrants dose reduction.
Symptom Monitoring
- Heartburn frequency and severity
- Dyspepsia (indigestion)
- Abdominal pain
- Nausea/vomiting
- Difficulty swallowing
- Blood in stool or vomit (signs of GI bleeding)
Special Patient Groups
Pregnancy
Famotidine is classified as Pregnancy Category B. Studies in animals have not shown harm to the fetus, and there are no adequate and well-controlled studies in pregnant women. It is generally considered safe for use during pregnancy when clearly needed.
Trimester-Specific Risks:
First Trimester:
Low risk, generally considered compatible.
Second Trimester:
Low risk, generally considered compatible.
Third Trimester:
Low risk, generally considered compatible.
Lactation
Famotidine is excreted into breast milk. However, the amount is generally considered low, and adverse effects in breastfed infants are unlikely. It is rated L2 (likely compatible) by LactMed. Use with caution and monitor the infant for potential effects (e.g., GI upset).
Infant Risk:
Low risk; monitor for potential GI upset (e.g., diarrhea, constipation) or changes in feeding patterns.
Pediatric Use
Dosing is weight-based and established for children 1 year and older for GERD and PUD. Use in infants <1 year is off-label but sometimes used with caution. Neonatal use is not well-established. Renal dose adjustment is crucial in pediatric patients with impaired renal function.
Geriatric Use
No specific dose adjustment is needed based on age alone. However, elderly patients are more likely to have decreased renal function, which necessitates dose adjustment. They may also be more susceptible to CNS side effects (e.g., confusion, dizziness), though these are rare with famotidine.
Clinical Information
Clinical Pearls
- Famotidine is generally well-tolerated with a low incidence of side effects.
- For nocturnal acid suppression, a single dose at bedtime is often effective.
- Can be taken with or without food.
- Separate administration from antacids by 1-2 hours to avoid reduced famotidine absorption.
- Consider dose reduction in patients with moderate to severe renal impairment (CrCl < 50 mL/min).
- Unlike cimetidine, famotidine has minimal to no effect on the CYP450 enzyme system, leading to fewer drug interactions.
Alternative Therapies
- Other H2-receptor antagonists (e.g., cimetidine, nizatidine)
- Proton pump inhibitors (PPIs) (e.g., omeprazole, lansoprazole, pantoprazole, esomeprazole, rabeprazole) - generally more potent for acid suppression.
- Antacids (for immediate, short-term relief)
- Sucralfate (for ulcer coating)
Cost & Coverage
Average Cost:
Typically $10-$50 per 50ml bottle of 40mg/5ml suspension
Generic Available:
Yes
Insurance Coverage:
Tier 1 (Preferred Generic) or Tier 2 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea to check with your pharmacist. If you have any questions or concerns about this medication, don't hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide detailed information about the overdose, including the medication taken, the amount, and the time it occurred.