Question

Ipratropium is administered via the inhalation route to elicit its therapeutic effect. It is a quaternary ammonium compound that is ionised. During inhalation, approximately 90% of the dose is swallowed where it is poorly absorbed from the gastrointestinal tract, while the rest of the dose enters the lung. Ipratropium has a bioavailability of 6% when administered via the inhalation route. Its half-life is 2 hours. Given its pharmacokinetic information, explain i) why ipratropium’s bioavailability and absorption are poor, ii) why the inhalation route is appropriate for ipratropium, and iii) what concentration would be left after 8 hours from measuring a concentration of 120 pg/mL.

Answer 1

1, Ipratropium is a topical agent that has poor absorption. due to the presence of charge in the 5 aren't nitrogen it has poor absorption in the mucosal area. serum level of ipratropium after administration very low and had only 1-2% of the administered dose. low-level peak after 1-2hours it prevents the bioavailability of 2%.
2, it is a bronchodilator. oral administration of ipratropium prevent wheezing, shortness of breath, chest tightness, coughing in people with COPD, chronic bronchitis.
3, Peak plasma concentration ranges from 419 to 802pg/mg obtained within three hours post-administration. half-life of elimination is about 2 hour after IV or inhalation administration, it has less bound to plasma albumin and alpha glycoprotein. it is partially metabolized to inactive ester hydrolysis products. ipratropium bromide does not penetrate the blood-brain barrier.