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Biomedical subjects

E J Segre

Publications and source records attributed to E J Segre.

At least 19 recordsLinked to original sources
PubMed1980

Naproxen sodium (Anaprox): pharmacology, pharmacokinetics and drug interactions.

Naproxen sodium (Anaprox) is a potent antiinflammatory and analgesic agent. The drug has demonstrated a variety of biologic actions, including stabilization of lysosomal membranes, but most of its therapeutic activity is probably mediated through prostaglandin synthesis inhibition. The linkage between inhibition of prostaglandin synthesis and relief of dysmenorrhea has been documented in clinical studies, reported elsewhere in this supplement. Of relevance is the selective activity of naproxen sodium on uterine microsomal preparations. Once dissolved in biologic fluids, naproxen and naproxen sodium are chemically identical species and have the same biologic properties. Administration of naproxen as the sodium salt (Anaprox), however, permits more rapid absorption from the gastrointestinal tract. In either form, the drug is essentially completely absorbed. Its metabolic half-life averages 13 hours. The metabolism of naproxen is quite simple: it is excreted almost entirely in the urine as the native molecule, its oxidative 6-desmethyl metabolite and their respective conjugates. Naproxen is an acidic drug that is highly bound to plasma albumin. It may thus be expected to displace and transiently increase the tissue availability of other protein-bound drugs. In practice, however, potential interactions with both warfarin and tolbutamide have been evaluated and do not appear to be of clinical significance. Naproxen has a high therapeutic index and a shallow dose-response curve, so the effect of other drugs on its pharmacokinetics is not likely to have a large clinical impact.

Acid-Base Equilibrium↗
PubMed1977

The treatment of dysmenorrhea with naproxen sodium: a report on two independent double-blind trials.

The efficacy of naproxen sodium (naproxen-Na) in dysmenorrhea has been established in two independent double-blind (placebo-controlled) studies. An initial dose of 550 mg. of naproxen-Na was followed by 275 mg. every six hours for a maximum of five days. Twenty patients were included in Study I (10 treated with naproxen-Na) and 23 patients in Study II (12 treated with naproxen-Na). Each patient received the medication during four dysmenorrheic episodes. Thus, a total of 172 treatment courses could be evaluated. A variety of efficacy criteria were measured: frequency of pill intake, changes in pain intensity, the degree of relief achieved by the medication, and need for additional analgesics. In both studies naproxen-Na was demonstrated to be superior to the placebo treatment with high statistical significance in each of these parameters.

Adult↗
PubMed1975

Naproxen metabolism in man.

In summary, naproxen is an acidic, highly albumin-bound drug. After oral administration, it is promptly and fully absorbed. The mean half-life of the drug in man is 13 hours, close to ideal for twice-daily administration. The only metabolite detected in man is the 6-desmethyl compound. Both it and naproxen itself are excreted in the urine, primarily as conjugates. The kinetics of naproxen binding to serum albumin tend to limit attainable plasma levels. They increase little if the dose is increased beyond 500 mg twice daily, since greater concentrations are rapidly cleared. Albumin binding and competitive displacement are also responsible for potential interactions of naproxen with drugs such as warfarin, sulfonylureas, and aspirin. Experience thus far does not indicate that any of the potential interactions are clinically meaningful.

Anti-Inflammatory Agents↗