Famotidine is usually the first choice to treat occasional heartburn if your symptoms occur less than two times per week. It can be used as needed, provides quick relief (within 15 to 30 minutes), and is usually less expensive than omeprazole. Omeprazole may be an option if your heartburn occurs two or more days per week. Both products are available without a prescription.

• Famotidine is classified as a histamine 2 (H-2) receptor antagonist, and is used to treat and prevent heartburn that occurs occur less than two times per week in adults and children 12 years of age or older.
• Omeprazole, a proton pump inhibitor (PPI), is indicated for the treatment of heartburn that occurs two or more days per week in adults 18 years and older. It is NOT used for heartburn prevention or for immediate relief.

Ask your doctor before using either product if you have had heartburn for over 3 months as this could be due to a more serious condition.

Both medicines are usually well-tolerated and serious side effects are infrequent in most people.

• Side effects of famotidine may include: headache, dizziness, constipation and diarrhea. If you have kidney problems, your doctor may need to adjust your dose of famotidine.
• Side effects of omeprazole may include: headache, cold symptoms (stuffy nose, sneezing, sore throat), fever, diarrhea, stomach pain / gas, nausea, vomiting, kidney problems and possible bone fractures with long-term use or high doses. Omeprazole may cause new or worsening symptoms of lupus.

This is not a complete list of side effects and others may occur. As with any medicine, common and serious side effects may vary among patients. Call your doctor for medical advice about side effects. Follow the directions on the OTC Drug Facts label or as prescribed by your doctor.

Related: Famotidine side effects and omeprazole side effects (more detail)

Both medicines are available over-the-counter in retail stores as a generic or brand name products. Generic medicines can help you save money. If you have questions about generics, check with your pharmacist.

Over-the-counter famotidine (Pepcid AC)

Uses:

• Relief of heartburn associated with acid indigestion and sour stomach
• Prevention of heartburn associated with acid indigestion and sour stomach brought on by eating/drinking certain foods and beverages

OTC famotidine (Pepcid AC) is taken once per day with a glass of water to treat symptoms. Do not chew the tablet. To prevent symptoms, take the medicine with water from 10 to 60 minutes before you eat food or drink beverages that cause heartburn or sour stomach. Do not use more than two 20 mg tablets per 24 hours. OTC famotidine is also available in a 10 mg strength tablet.

Over-the-counter omeprazole (Prilosec OTC)

Use: Treatment of frequent heartburn (occurring 2 or more days a week)

• OTC omeprazole (Prilosec OTC) is taken once a day (every 24 hours) over a 14-day course of treatment, NOT as needed for symptoms. It is not used for immediate relief of heartburn.
• Take with a full glass of water prior to eating in the morning and swallow the tablet whole. Do not crush or chew it.
• It may take 1 to 4 days before your symptoms improve.
• You should allow at least 4 months to pass before you start a new 14-day course of treatment.

Note: Contact your doctor if your heartburn continues, worsens or returns after 14 days of using either product. Also check with your doctor first if you have had heartburn for over 3 months as this could be a more serious condition.

These medicines may be only one part of a treatment regimen that also includes changes in your diet or lifestyle habits, such as:

• weight loss
• elevation of the head of the bed
• avoidance of tobacco, alcohol and dietary triggers (for example: coffee, chocolate, spicy foods, carbonated beverage and peppermint).

Check with your healthcare provider if you have concerns about usage or side effects.

This is not all the information you need to know about famotidine (Pepcid AC) or omeprazole (Prilosec OTC) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.