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Zantac GELdose Side Effects

Generic Name: ranitidine

Note: This page contains side effects data for the generic drug ranitidine. It is possible that some of the dosage forms included below may not apply to the brand name Zantac GELdose.

For the Consumer

Applies to ranitidine: oral solution, oral tablets and tablets for, oral tablets effervescent for solution, parenteral injection, parenteral injection for iv infusion only

Side effects include:

Oral or parenteral therapy: Headache, sometimes severe.

IM therapy: Transient pain at injection site.

IV therapy: Transient local burning or itching.

For Healthcare Professionals

Applies to ranitidine: compounding powder, injectable solution, intravenous solution, oral capsule, oral granule effervescent, oral syrup, oral tablet, oral tablet effervescent


Ranitidine (the active ingredient contained in Zantac GELdose) is generally well tolerated.[Ref]


Gastrointestinal side effects have included constipation, nausea/vomiting, diarrhea, abdominal pain, and rare reports of pancreatitis. Rebound acid hypersecretion has been reported after discontinuation of therapy. A case report of coinfection with Giardia lamblia and Clostridium difficile has been attributed to the achlorhydria induced by ranitidine (the active ingredient contained in Zantac GELdose) predisposing the patient to the enteric infection.[Ref]


Hepatic side effects have included transient and minor increases in serum transaminases, which may be important in patients with liver disease. There are rare reports of ranitidine-induced hepatitis with or without jaundice, one case of subfulminant hepatitis with a fatal outcome, and very rare cases of acute interstitial nephritis.[Ref]

Overall, serious hepatotoxicity due to ranitidine is rare. Hepatocellular, hepatocanalicular, and mixed-type injury have been reported. In most cases, hepatotoxicity has been associated with fever, chills, nausea, and occasionally rash and eosinophilia, with onset of symptoms early in the course of therapy. Such symptomatology is suggestive of a hypersensitivity etiology. The majority of cases resolve following discontinuation of ranitidine therapy although, at least two fatalities have been reported.

In a study with healthy volunteers , SGPT values were increased to at least twice the pretreatment levels in 6 of 12 subjects receiving 100 mg intravenously four times daily for 7 days, and in 4 of 24 subjects receiving 50 mg intravenously four times daily for 5 days.[Ref]


Hypersensitivity side effects have included rash, urticaria, bronchospasm, fever, eosinophilia, angioneurotic edema, acute eosinophilic pneumonia and anaphylaxis. Vasculitis associated with immune complexes has also been reported.[Ref]


Serious hematologic abnormalities are rare. Patients with renal dysfunction or those who are critically ill may be at increased risk. While the mechanism of bone marrow toxicity is unknown, ranitidine (the active ingredient contained in Zantac GELdose) concentration-dependent inhibition of hematopoietic progenitor cell activity and hypersensitivity have both been proposed. Hematologic abnormalities typically resolve upon discontinuation of ranitidine therapy.

Cases of ranitidine-induced thrombocytopenia are typically immune-mediated.[Ref]

Hematologic side effects have included leukopenia, granulocytopenia, and thrombocytopenia in a few patients. These were usually reversible. Rare cases of agranulocytosis, pancytopenia, sometimes with marrow hypoplasia, aplastic anemia, and acquired immune hemolytic anemia have been reported.[Ref]


Endocrine side effects have been reported rarely. These have included gynecomastia, impotence, and loss of libido in male patients, although, the incidence was similar to that in the general population. Hyperprolactinemia, amenorrhea, reductions in circulating levothyroxine and hypergastrinemia have also been reported.[Ref]

Ranitidine does not possess antiandrogenic properties nor has it been associated with significant changes in pituitary hormone concentrations under study conditions. However, increases in prolactin serum concentrations following administration of high doses as well as decreases in levothyroxine serum concentrations during short-term therapy have been reported. Thyroid hormone levels are not affected during long-term therapy.[Ref]

Nervous system

The mechanism by which ranitidine (the active ingredient contained in Zantac GELdose) induces mental status changes is not well established but appears to involve increased serum concentrations of ranitidine. Renal dysfunction, advanced age, and critical illness appear to be associated with an increased risk of central nervous system toxicity. Onset of symptoms is typically within the first few weeks of therapy, but may be delayed. Following discontinuation of ranitidine, mental status usually normalizes over several days.[Ref]

Nervous system side effects have been reported rarely. These have included headache (sometimes severe), somnolence, dizziness, malaise, and vertigo. Reversible mental confusion, agitation, depression, and hallucinations have been reported, predominantly in severely ill elderly patients. Hostility, mania, mental status changes, dystonia, reversible involuntary motor disturbances have also been reported.[Ref]


Renal side effects have included mild elevations in serum creatinine. Rare cases of interstitial nephritis and Fanconi's syndrome have been reported.[Ref]


Dermatologic side effects have included alopecia, rash, pruritus, contact dermatitis, erythema multiforme, cutaneous vasculitis, and toxic epidermal necrolysis.[Ref]

Two cases of toxic epidermal necrolysis have been reported in patients with underlying idiopathic thrombocytopenia purpura. A 72-year-old male also experienced a photosensitivity reaction that resolved after ranitidine was discontinued.[Ref]


Ocular side effects have included blurred vision and increased intraocular pressure in a patient with a history of glaucoma.[Ref]


Other reported side effects have included tiredness and one case of aseptic meningitis.[Ref]


Cardiovascular side effects have rarely included tachycardia, bradycardia, atrioventricular block, and premature ventricular beats. Several cases of bradycardia following intravenous administration of ranitidine (the active ingredient contained in Zantac GELdose) have been reported. Ranitidine-induced bradycardia may be due to a rise in the serum histamine concentration or due to a direct effect of ranitidine on cardiac H2 receptors.[Ref]


Musculoskeletal side effects have included arthralgias and myalgias.[Ref]


Respiratory side effects have included an increased risk of developing pneumonia in patients taking H2 receptor antagonists versus those who had stopped treatment. However, a causal relationship has not been established.


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It is possible that some side effects of Zantac GELdose may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

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