Note: This document contains side effect information about calcium carbonate / famotidine / magnesium hydroxide. Some dosage forms listed on this page may not apply to the brand name Duo Fusion.

Applies to calcium carbonate / famotidine / magnesium hydroxide: oral tablet chewable.

Serious side effects of Duo Fusion

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like 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; or swelling of the mouth, face, lips, tongue, or throat.
• Dizziness or passing out.
• A fast heartbeat.
• A heartbeat that does not feel normal.
• Muscle weakness.

Other side effects of Duo Fusion

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Headache.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

For Healthcare Professionals

Applies to calcium carbonate/famotidine/magnesium hydroxide: oral tablet chewable.

Gastrointestinal

Uncommon (0.1% to 1%): Abdominal discomfort, abdominal pain, diarrhea, dry mouth, flatulence, nausea, vomiting

Rare (less than 0.1%): Abdominal pain upper, constipation

Frequency not reported: Abdominal distension, abnormal feces, dyspepsia, eructation^[Ref]

Nervous system

Uncommon (0.1% to 1%): Dizziness, dysgeusia

Rare (less than 0.1%): Somnolence

Frequency not reported: Paresthesia^[Ref]

Other

Uncommon (0.1% to 1%): Asthenia, fatigue

Rare (less than 0.1%): Malaise^[Ref]

Respiratory

Uncommon (0.1% to 1%): Oropharyngeal discomfort, oropharyngeal pain^[Ref]

Dermatologic

Uncommon (0.1% to 1%): Rash

Rare (0.01% to 0.1%): Pruritus, urticaria

Very rare (less than 0.01%): Alopecia^[Ref]

Hypersensitivity

Rare (less than 0.1%): Anaphylactic reaction, angioedema, hypersensitivity^[Ref]

Hepatic

Rare (less than 0.1%): Cholestatic jaundice, hepatic enzyme abnormal, liver disorder^[Ref]

Hematologic

Rare (less than 0.1%): Leukopenia, pancytopenia^[Ref]

Metabolic

Rare (less than 0.1%): Decreased appetite

Frequency not reported: Thirst^[Ref]

Musculoskeletal

Rare (less than 0.1%): Arthralgia^[Ref]

Psychiatric

Frequency not reported: Nervousness^[Ref]

Endocrine

Rare (less than 0.1%): Gynecomastia^[Ref]