Acute pulmonary effects of three nebulizers for administering aerosol pentamidine: comparison of Parineb to Fisoneb and Respirgard II.

We conducted a prospective, unblinded, nonrandomized, multiple crossover study to assess the acute pulmonary effects of a new jet nebulizer-Parineb, comparing it to Respirgard II (jet nebulizer) and Fisoneb (ultrasonic nebulizer) for administering aerosol pentamidine (AP). Twenty-three HIV patients received AP at 60 mg dissolved in 3 ml sterile water with Parineb and Fisoneb and 300 mg dissolved in 5 ml sterile water with Respirgard II on three successive clinic visits. Twelve patients known to develop bronchospasm with AP received 200 micrograms of salbutamol as premedication for all three nebulizers. Eleven subjects received AP without bronchodilator premedication. All subjects had a reduction in flow rates with AP. No significant difference was noted in the reduction of flow rates between the three nebulizers in those patients without prior history of bronchospasm with AP. However, there was a significantly greater reduction in flow rates with Parineb in patients with known AP-induced bronchospasm despite premedication with bronchodilator. This decrease in flow rates with Parineb was not felt by patients based on the subjective rating of cough using a visual analog score when compared to the other two nebulizers. Parineb should be used cautiously in individuals with known AP-induced bronchospasm.

Lack of desensitization to aerosol pentamidine with long-term use.

OBJECTIVE: To assess whether long-term exposure to aerosol pentamidine (AP) results in desensitization. STUDY DESIGN: Phase I-A retrospective, two group comparative study. Phase II-A prospective intervention study. METHODS: Patients were selected from a 5-year database of 1200 individuals infected with the human immunodeficiency virus (HIV) who received AP as prophylaxis for Pneumocystis carinii pneumonia (PCP). In phase I, serial pre- and post-AP spirometry data of 33 subjects with significant bronchospasm on initial exposure to AP, who thus received aerosol salbutamol (AS) as regular pre-AP premedication for over 18 months, were compared to 33 matched controls who did not use AS. In phase II, 13 of the original group of 33 patients who required regular AS consented to a follow-up AP treatment without AS premedication to examine the effects of discontinuing AS premedication. RESULTS: Phase I: on their initial AP treatment without AS premedication, the drop in mean FVC, FEV1, and FEV1/FVC values post-AP therapy was significantly lower for the AS group compared to the control group. The mean FEV1/FVC value for the AS group was 84% pre-AP and dropped to 75% post-AP therapy. For the control group the corresponding FEV1/FVC values were 83% (pre-AP) and 79% (post-AP). After using AS as premedication for AP for 18 months, the AS group did not show any reduction in flow rates as the mean FEV1/FVC values were 77% (pre-AP) and 80% (post-AP). The values in the control group were 80 and 78%, respectively. In phase II, when the 13 subjects who needed regular AS premedication were exposed to AP without premedication with AS, the flow rates are reduced in the same magnitude as observed at initial exposure to AP. CONCLUSIONS: The results of this study show that the prevention of bronchospasm with AS premedication while receiving long-term AP administration is due to the bronchodilator effect of AS, as desensitization is not achieved after over 18 months of exposure. These findings support long-term regular premedication with AS in patients with documented AP-induced bronchospasm.