Following a single oral dose of 150 mg, serum concentrations of ranitidine  are in this range up to 12 hours. Moreover, patient response rates demonstrated that the effect on heartburn extends through both the day and night time periods. Assuming weight of five yrs old is 45lbs, ( roughly 20 kilos), dose of Zantac (ranitidine) is 20 mg by mouth twice daily. Intravenous LDAntacid should be given as needed for relief of pain (see The current recommended adult oral dosage is 150 mg twice daily. The major route of elimination is renal. If an ulcer has not healed after treatment, 150 mg twice daily dosage should be instituted followed, if need be, by maintenance treatment of 150 mg at night. Dosages should be adjusted to individual patient needs, and should continue as long as clinically indicated. It inhibits basal and stimulated secretion of gastric acid, reducing both the volume and the acid and pepsin content of the secretion. The improvement was maintained throughout the 6-week trial period.

Alternatively, the injection is also available. Use of Ranitidine Tablets was followed by healing of ulcers in 8 of 19 (42%) patients who were intractable to previous therapy.The US trial indicated that Ranitidine Tablets 150 mg twice daily significantly reduced the frequency of heartburn attacks and severity of heartburn pain within 1 to 2 weeks after starting therapy. Renal clearance is approximately 500 mL/min, which exceeds glomerular filtration indicating net renal tubular secretion.Limited pharmacokinetic data have shown that there are no significant differences in half-life (range for children 3 years and above: 1.7 - 2.2 h) and plasma clearance (range for children 3 years and above: 9 - 22 ml/min/kg) between children and healthy adults receiving oral ranitidine when correction is made for body weight.In patients over 50 years of age, half-life is prolonged (3-4 h) and clearance is reduced, consistent with the age-related decline of renal function.

Rare reports suggest that ranitidine may precipitate acute porphyric attacks in patients with acute porphyria. Ranitidine should therefore be avoided in patients with a history of acute porphyria.In patients such as the elderly, persons with chronic lung disease, diabetes or the immunocompromised, there may be an increased risk of developing community acquired pneumonia. Prophylaxis of acid aspiration (Mendelson's) syndrome:150 mg oral dose can be given 2 hours before anaesthesia, and preferably also 150 mg the previous evening. warfarin).

Two distinct peaks or plateau in the absorption phase result from reabsorption of drug excreted into the intestine.

Ranitidine Pharmacokinetics in Pediatric Patients Following Oral DosingTable 2. For example, cheap sominex clone 4b comprising an amino acid substitution of glutamic acid for glycine at position 96 (e.g., SEQ ID NO. The absolute bioavailability of ranitidine is 50-60% and plasma concentrations increase proportionally with increasing dose up to 300 mg.Ranitidine is not extensively bound to plasma proteins (15%), but exhibits a large volume of distribution ranging from 96 to 142 L.Ranitidine is not extensively metabolised. If an ulcer has not healed after treatment, 150 mg twice daily dosage should be instituted followed, if need be, by maintenance treatment of 150 mg at night. Each tablet also contains the inactive ingredients colloidal silicon dioxide, croscarmellose sodium, hypromellose, magnesium stearate, microcrystalline cellulose, polydextrose, titanium dioxide, triethyl citrate and FD&C Yellow #6.Ranitidine Tablets are a competitive, reversible inhibitor of the action of histamine at the histamine HPlasma clearance measured in 2 neonatal patients (less than 1 month of age) was considerably lower (3 mL/min/kg) than children or adults and is likely due to reduced renal function observed in this population (see Serum concentrations necessary to inhibit 50% of stimulated gastric acid secretion are estimated to be 36 to 94 ng/mL. The active ingredient in Ranitidine Tablets USP, 150 mg and Ranitidine Tablets USP, 300 mg is ranitidine hydrochloride (HCl), USP, a histamine HEach Ranitidine Tablet USP, 150 mg for oral administration contains 167.4 mg of ranitidine HCl equivalent to 150 mg of ranitidine. Continue ranitidine for further 2 wk. Protect from light. MAXIMUM STRENGTH Ranitidine Tablets 150 mg contain 150 mg of ranitidine (as ranitidine hydrochloride USP, 167.414 mg), a medicine that doctors have prescribed more than 200 million times worldwide. Store in the original package in order to protect from moisture.Ranitidine Film-coated Tablets are available in cartons containing blister packs of Aluminium-Aluminium foils of 10, 30 and 60 tablets along with a leaflet inside.No special requirements for disposal.