"60-80% bound to plasma proteins, primarily albumin and α₁-acid glycoprotein. The presence of cirrhosis or active viral hepatitis does not appear to affect the extent of protein binding. "@en . . . . . . . . "Excreted in the urine. The proportion of drug that is excreted unchanged or as metabolites is dependent on pH. When urine pH is uncontrolled, 5-30% of the meperidine dose is excreted as normeperidine and approximately 5% is excreted unchanged. Meperidine and normeperidine are found in acidic urine, while the free and conjugated forms of meperidinic and normperidinic acids are found in alkaline urine. "@en . "Meperidine crosses the placenta and is distributed into breast milk. "@en . . "57-42-1"@en . . "Isonipeca\u00EFne"@en . "The oral bioavailability of meperidine in patients with normal hepatic function is 50-60% due to extensive first-pass metabolism. Bioavailability increases to 80-90% in patients with hepatic impairment (e.g. liver cirrhosis). Meperidine is less than half as effective when administered orally compared to parenteral administration. One study reported that 80-85% of the drug administered intramuscularly was absorbed within 6 hours of intragluteal injection in health adults; however, inter-individual variation and patient-specific variable appear to cause considerable variations in absorption upon IM injection. "@en . . . "Petidina"@en . . . . . . "approved"@en . . . . . . . . . . "Pethidin"@en . . . . . . . . . . . "Humans and other mammals"@en . . . . . . . . . . . . . . . "Take without regard to meals. Avoid alcohol."@en . . . . . . . . . . . . . . . . . . . . . . . "Pethidine"@en . . . . . . . . . . . "Pethidine dbl"@en . . . "Meperidine is primarily a kappa-opiate receptor agonist and also has local anesthetic effects. Meperidine has more affinity for the kappa-receptor than morphine. Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine and noradrenaline is inhibited. Opioids also inhibit the release of vasopressin, somatostatin, insulin and glucagon. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability."@en . . . . . "Meperidine"@en . . . "Initial distribution phase (t_{1/2 α}) = 2-11 minutes; terminal elimination phase (t_{1/2 β}) = 3-5 hours. In patients with hepatic dysfunction (e.g. liver cirrhosis or active viral hepatitis) the t_{1/2 β} is prolonged to 7-11 hours."@en . . "Petydyna"@en . "Spasmodolin"@en . . . " "@en . . "Used to control moderate to severe pain."@en . . . . . . . . . . "P\u00E9thidine"@en . . . . "A narcotic analgesic that can be used for the relief of most types of moderate to severe pain, including postoperative pain and the pain of labor. Prolonged use may lead to dependence of the morphine type; withdrawal symptoms appear more rapidly than with morphine and are of shorter duration. [PubChem]"@en . . . " "@en . . . . "Pethidinum"@en . . . . . . . . . "Spasmedal"@en . . . . . "Sauteralgyl"@en .