Can ranitidine (histamine-2 receptor antagonist) 50mg be administered intramuscularly (IM) in the gluteal region to adults?

Intramuscular Administration of Ranitidine 50mg in the Gluteal Region for Adults

Yes, ranitidine 50mg can be safely administered intramuscularly in the gluteal region to adults, as this is the standard recommended dose and route for parenteral administration when oral administration is not possible. 1

Dosing and Administration Guidelines

• The FDA-approved intramuscular dose of ranitidine for adults is 50mg every 6 to 8 hours, which can be administered without dilution 1
• Intramuscular injection should be administered in the gluteal region (posterior lateral aspect of the upper buttocks), which is a recommended site for intramuscular injections in adults 2
• Absorption from intramuscular sites is virtually complete, with a bioavailability of 90% to 100% compared with intravenous administration 1
• Mean peak plasma levels of 576 ng/mL occur within 15 minutes or less following a 50mg intramuscular dose 1

Clinical Considerations

• Intramuscular ranitidine is indicated for patients with pathological hypersecretory conditions, intractable duodenal ulcers, or in patients who are unable to take oral medication 1
• For stress ulcer prophylaxis in critically ill patients, "low-dose" H2RA therapy is defined as a daily dose of ≤40mg famotidine, ≤150mg IV ranitidine, or ≤300mg enteral ranitidine 2
• When administering intramuscular injections in the gluteal region, use the posterior lateral aspect of both upper buttocks to avoid major nerves and blood vessels 2

Special Populations and Precautions

• For patients with impaired renal function (creatinine clearance <50 mL/min), the recommended dosage is 50mg every 18 to 24 hours, which may be increased to every 12 hours with caution if needed 1
• In elderly patients, the plasma half-life is prolonged and total clearance is reduced due to decreased renal function, with an elimination half-life of 3.1 hours compared to 2.0-2.5 hours in younger adults 1
• The overall incidence of adverse effects with ranitidine is very low (less than 2%), similar to placebo 3

Potential Adverse Effects

• The most common side effects include headaches, tiredness, dizziness, and mild gastrointestinal disturbances (diarrhea, constipation, nausea) 4
• Cardiovascular side effects are extremely rare with oral ranitidine (approximately 1 in 1 million patients), but can include sinusal bradycardia and atrioventricular blockade, especially after rapid intravenous administration 4
• Neuropsychiatric complications such as confusion, disorientation, and hallucinations occur rarely (less than 1%) and primarily in critically ill patients or those with renal or hepatic failure 4

Common Pitfalls to Avoid

• Do not administer the injection too rapidly if using the IV route (intramuscular administration does not have this concern) 4
• Avoid using ranitidine in patients with known hypersensitivity to the medication 1
• When administering in the gluteal region, ensure proper technique to avoid sciatic nerve injury by using the upper outer quadrant of the buttock 2