PENTACARINAT Powder for reconstitution Ref.[9290] Active ingredients: Pentamidine

After intravenous infusion, plasma levels of pentamidine fall rapidly during the first two hours to one twentieth of peak levels, followed by a much slower decline thereafter. After intramuscular administration, the apparent volume of distribution of pentamidine is significantly greater (>3 times) than that observed following intravenous administration.

Elimination of half-lives after parenteral administration were estimated to be about 6 hours after intravenous infusion in patients with a normal renal function. The elimination of half-life following intramuscular injection was found to be about 9 hours.

Following parenteral administration, pentamidine appears to be widely distributed in the body and probably accumulates in tissue, particularly the liver and kidney. Only a small amount is excreted unchanged in the urine.

When administered by the use of a nebuliser, human kinetic studies revealed significant differences when compared to parenteral administration. Aerosol administration resulted in a 10-fold increase in bronchial alveolar lavage (BAL) supernatant fluid and an 80-fold increase in BAL sediment concentrations in comparison with those seen with equivalent intravenous doses.

Limited data suggests that the half-life of pentamidine in BAL fluid is greater than 10 to 14 days. Peak plasma concentrations after inhalation therapy were found to be approximately 10% of those observed with equivalent intramuscular doses and less than 5% of those observed following intravenous administration. This suggests that systemic effects by the inhalation route are less likely.

Long term pulmonary parenchymal effects of aerosolised pentamidine are not known. Lung volume and alveolar capillary diffusion, however, have not been shown to be affected by high doses of pentamidine administered by inhalation to AIDS patients.

No additional data of relevance to the prescriber.