Effect of salicylic acid on the plasma protein binding and pharmacokinetics of misoprostol acid

Pharmacokinetics and Bioequivalence of Misoprostol Tablets: An Open-Label, Randomized, Single-dose, Crossover Study With Healthy Chinese Volunteers

Misoprostol is a synthetic prostaglandin E1 derivative that has been used to treat duodenal and gastric ulcers, and to prevent ulcers caused by nonsteroidal anti-inflammatory drugs in many countries. Misoprostol can also be used for medical abortion. This study aimed to investigate the pharmacokinetic profiles of misoprostol tablets (test product) by comparing them with Cytotec (200 μg) (reference product). To assess the bioequivalence between test and reference products, a two-sequence, two-period crossover study was conducted with 48 healthy Chinese subjects enrolled under fasting conditions. A validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was used to determine the concentration of misoprostol acid in plasma. A mixed model analysis of variance was used to calculate the bioequivalence of pharmacokinetic (PK) parameters. The point estimate of geometric mean ratios with 90% confidence intervals for the maximum observed concentration (C_max ) and the area under the concentration-time curve (AUC_0-t ) for misoprostol acid in reference and test products were 107.8% and 106.5%, respectively (range 80%-125%). Additionally, none of the secondary PK parameters presented significant differences. No severe or more than moderate adverse events were detected in the 48 subjects. However, one subject discontinued the treatment due to drug-related gastrointestinal reactions. All adverse events were mild with rates of 19.2% and 22.9% after the administration test and reference products, respectively. Overall, the bioequivalence between the two misoprostol products was demonstrated in fasting conditions, and all subjects tolerated both treatments.

Community Violence Exposure and Adolescent Pregnancy in Chicago

This study examined the association between community violence exposure (CVE), sex without contraception, and adolescent pregnancy in Chicago. A self-administered, online survey was conducted among 15- to 19-year-old girls from the South and West sides of Chicago from October to March 2018. Participants were recruited via community organization partnerships and social media advertising. The survey included questions about CVE, sexual behaviors, and covariates that are known to contribute to sexual risk taking. CVE was measured via a validated index of seven questions that measured individual experiences with violence. Multivariable and logistic regression analyses were performed to examine the association between CVE, penile-vaginal intercourse without contraception, and ever being pregnant. The final sample included 644 girls. Levels of CVE were high: 62.87% of girls reported that a close friend or relative died because of violence and 41.60% were a victim of violence. Nearly half (48.69%) of girls had penile-vaginal intercourse and 6.01% had been pregnant. For each standard deviation increase in CVE score, the odds of penile-vaginal intercourse without contraception (odds ratio [OR] = 1.69, 95% confidence interval [CI] = [1.27, 2.25]) and the odds of ever being pregnant (OR = 1.87, 95% CI = [1.36, 2.57]) increased. These results remained significant when adjusting for demographic, psychosocial, institutional, and interpersonal factors. Findings suggest that girls in Chicago who are exposed to higher levels of community violence have an increased likelihood of experiencing penile-vaginal intercourse without contraception and teenage pregnancy, even when adjusting for other predictors to teenage pregnancy.

Predicting Drug Binding to Human Serum Albumin and Alpha One Acid Glycoprotein in Diseased and Age Patient Populations

Plasma protein binding, namely the fraction unbound (f_u), can be an important determinant of the disposition and response of drugs. The primary objective of this study was to predict f_u values of 183 drugs utilizing either a single binding protein model, where the predominant binding protein had been established, or a multiple binding protein model (MBPM), where the relative binding contribution of human serum albumin (HSA) or alpha 1 acid glycoprotein (AAG) is known. Mean protein concentrations, dependent on disease or age, were used to account for changes in f_u. A simple scaling approach for binding protein concentration was employed to account for quantitative changes in molar concentrations of either HSA or AAG in their respective conditions. The MBPM predictive model works best if the relative binding contribution of HSA and AAG is known, and a scaler for the change in protein concentration can be adjusted accordingly. The value of MBPM was most evident when considering reported changes in lidocaine binding because of increasing AAG concentration in response to trauma. The present approach enhances the ability to predict f_u in diseased and age populations because of quantitative changes in major binding proteins.

Acute Hemolytic Anemia With Acanthocytosis Associated With High-Dose Misoprostol for Medical Abortion

We report a case of acute hemolytic anemia in a 21-year-old Nigerian woman after high-dose misoprostol (4 mg), used for medical abortion. The major causes of inherited or immune hemolytic anemia were excluded. The patient's peripheral blood smear showed acanthocytes and anisopoikilocytosis, which progressively disappeared in the days postingestion. We evaluated RBC features, and we observed reduced RBC Na+ and K+ content and abnormalities in membrane cation transport pathways and in Ca2+ activated K+ channel (Gardos channel), suggesting possible direct effects of misoprostol on RBCs. Although further studies need to be carried out, the present case suggests that high-dose misoprostol, a prostaglandin E1 analogue, severely affects RBC features and causes an acquired acute hemolytic anemia, which is self-limited when misoprostol is withdrawn.

The effect of dosing interval on the efficacy of misoprostol in the prevention of aspirin-induced gastric injury

The effect of twice-daily administration of misoprostol on aspirin-induced gastric injury was evaluated. Twenty-four random-source dogs were divided into groups that received aspirin and misoprostol as follows: group I, aspirin 25 mg/kg PO q8h and placebo PO q8h; group II, aspirin 25 mg/kg PO q8h and misoprostol 3 microg/kg PO q8h; group III, aspirin 25 mg/kg PO q8h, misoprostol 3 microg/kg PO q12h, and placebo PO q24h; and group IV, aspirin 25 mg/kg PO q8h, misoprostol 3 microg/kg PO q24h, and placebo PO q12h for 28 days. Gastroscopy was performed on days -9, 5, 14, and 28. Visible lesions were scored on a scale of 1 (mucosal hemorrhage) to 11 (perforating ulcer). No difference in total score was identified between groups I and IV on any day. Median total scores for groups II and III were significantly (P < or = .05) lower compared to groups I and IV on day 5. Group III had a significantly lower score (P < or = .05) than groups I, II, and IV on day 28. This study suggests that misoprostol 3 microg/kg PO q12h is as effective as misoprostol 3 microg/kg PO q8h in preventing aspirin-induced gastric injury in this model. However, misoprostol 3 microg/ kg PO q8h was less effective in preventing aspirin-induced gastric injury on days 14 and 28 than in previous studies. No difference among numbers of dog-days of vomiting, diarrhea, or anorexia was detected among groups.

Misoprostol therapeutics revisited

Misoprostol, a prostaglandin E1 analog, is a racemate of four stereoisomers. On administration it rapidly de-esterifies to its active form, misoprostolic acid. Misoprostolic acid is 85% albumin bound and has a half-life of approximately 30 minutes. It is excreted in urine as inactive metabolites. No significant drug interactions have been reported. Besides its gastrointestinal protective and uterotonic activities, misoprostol regulates various immunologic cascades. It inhibits platelet-activating factor and leukocyte adherence, and modulates adhesion molecule expression. It protects against gut irradiation injury, experimental gastric cancer, enteropathy, and constipation. It improves nutrient absorption in cystic fibrosis. Misoprostol has utility in acetaminophen and ethanol hepatotoxicity, hepatitis, and fibrosis. It is effective in asthmatics and aspirin-sensitive asthmatic and allergic patients. It lowers cholesterol and severity of peripheral vascular diseases, prolongs survival of cardiac and kidney transplantation, synergizes cyclosporine, and protects against cyclosporine-induced renal damage. It works against drug-induced renal damage, interstitial cystitis, lupus nephritis, and hepatorenal syndrome. It is useful in periodontal disease and dental repair. Misoprostol enhances glycosoaminoglycan synthesis in cartilage after injury. It prevents ultraviolet-induced cataracts and reduces intraocular pressure in glaucoma and ocular hypertension. It synergizes antiinflammatory and analgesic effects of diclofenac or colchicine and has been administered to treat trigeminal neuralgic pain. It reduces chemotherapy-induced hair loss and recovery time from burn injury, and is effective in treating sepsis, multiple sclerosis, and pancreatitis.