Ranitidine is a nonimidazole H2 blocker. It is about 5 times more potent than cimetidine. Pharmacokinetics: Bioavailability of 30-80 %, elimination mostly by the renal route. No anti-androgenic action doesn't increase prolactin secretion or spare estradiol from Hepatic metabolism. No effect on gastric smooth muscle function and on lower oesophageal sphincter pressure. Other GI secretions are not significantly reduced, little effect on heart & BP.
It can inhibit renal clearance of basic drugs that are secreted by renal tubules. Lesser permeability into the brain- lower propensity to cause CNS effects. Doesn't significantly affect hepatic metabolism of other drugs. Adverse Effects: Overall incidence A headache Diarrhoea Constipation Dizziness Rashes are infrequent, but fast IV injection causes pain and rashes along the vein of injection. Haematological changes Hepatic injuries CNS…
