The side effects for Zantac, the brand name for ranitidine hydrochloride, may last up to 8 hours, according Everyday Health. Side effect longevity is dependent on the overall health of the individual, notes Drugs.com. Decreased renal function in geriatric patients reduces how quickly the drug is eliminated, which can prolong side effects.
The elimination half-life of Zantac is 2.5 to 3 hours in healthy adults and 3 to 4 hours in geriatric patients, according to Drugs.com. The dosage for patients with kidney failure should be adjusted accordingly. Oral and intravenous administration also cause a slight difference in overall absorption and elimination rates.
Zantac can cause a serious allergic reaction in some people, states Everyday Health. In the instance of hives, breathing issues or swelling of the face, lips or tongue, emergency services are needed. Severe side effects that may occur include fast or slow heart rate, chest pain, shortness of breath, dark urine, jaundice, unusual weakness and vision issues. A person who experiences any of these severe side effects is advised to stop taking Zantac and call a physician.
Zantac is used to treat conditions such as GERD, ulcers on a short-term basis and erosive esophagitis, according to Drugs.com. Placebo-controlled studies of Zantac lasting longer than one year to test these conditions have not been completed, as of 2015. To reduce the risk of negative side effects, it is important to follow the advice of a physician concerning length of use, and to list all current medications before taking Zantac.