Overview
DESCRIPTION Pentamidine Isethionate for inhalation, an antifungal agent, is a nonpyrogenic lyophilized product. After reconstitution with Sterile Water for Injection, USP, Pentamidine Isethionate is administered by inhalation via the Respirgard ® II nebulizer [Marquest, Englewood, CO] (see DOSAGE AND ADMINISTRATION ).
Mechanism of Action
CLINICAL PHARMACOLOGY Microbiology Mechanism of Action Studies suggest that the pentamidine isethionate interferes with microbial nuclear metabolism by inhibition of DNA, RNA, phospholipid and protein synthesis. However, the mode of action is not fully understood. Activity in vitro and in vivo Pentamindine isethionate, an aromatic diamidine, is know to have activity against Pneumocystis jiroveci. Pharmacokinetics In 5 AIDS patients with suspected Pneumocystis jiroveci pneumonia (PJP), the mean concentrations of pentamidine determined 18 to 24 hours after inhalation therapy were 23.2 ng/mL (range 5.1 to 43.0 ng/mL) in bronchoalveolar lavage fluid and 705 ng/mL (range 140 to 1336 ng/mL) in sediment after administration of a 300 mg single dose via the Respirgard ® II nebulizer.
Indications
- INDICATIONS AND USAGE Pentamidine Isethionate is indicated for the prevention of Pneumocystis jiroveci pneumonia (PJP) in high-risk, HIV-infected patients defined by one or both of the following criteria: i. a history of one or more episodes of PJP ii. a peripheral CD4+ (T4 helper/inducer) lymphocyte count less than or equal to 200/mm 3 . These indications are based on the results of an 18-month randomized, dose-response trial in high risk HIV-infected patients and on existing epidemiological data from natural history studies.
Common Doses
- 300 mg
- 6 mL
Dosage
DOSAGE AND ADMINISTRATION IMPORTANT: PENTAMIDINE ISETHIONATE MUST BE DISSOLVED ONLY IN STERILE WATER FOR INJECTION, USP. DO NOT USE SALINE SOLUTION FOR RECONSTITUTION BECAUSE THE DRUG WILL PRECIPITATE. DO NOT MIX THE PENTAMIDINE ISETHIONATE SOLUTION WITH ANY OTHER DRUGS. DO NOT USE THE RESPIRGARD ® II NEBULIZER TO ADMINISTER A BRONCHODILATOR. Reconstitution The contents of one vial (300 mg) must be dissolved in 6 mL Sterile Water for Injection, USP. Place the entire reconstituted contents of the vial into the Respirgard ® II nebulizer reservoir for administration.
Contraindications
- CONTRAINDICATIONS Pentamidine Isethionate is contraindicated in patients with a history of an anaphylactic reaction to inhaled or parenteral pentamidine isethionate.
Side Effects
- ADVERSE REACTIONS The most frequently reported unsolicited adverse events (1 to 5%) in clinical trials, regardless of their relation to Pentamidine Isethionate therapy were as follows (n=931): Body as a Whole: Night sweats. Gastrointestinal: Diarrhea and nausea. Hematologic: Anemia. Infection: Bronchitis, non-specific herpes, herpes zoster, non-specific influenza, oral Candida, pharyngitis, sinusitis, and upper respiratory tract. Nervous System: Headache. Respiratory System: Chest pain, cough, and wheezing. Special Senses: Bad taste.
Interactions
- Drug Interactions While specific studies on drug interactions with pentamidine isethionate have not been conducted, the majority of patients in clinical trials received concomitant medications, including zidovudine, with no reported interactions. Because the nephrotoxic effects may be additive, the concomitant or sequential use of pentamidine isethionate and other nephrotoxic drugs such as aminoglycosides, amphotericin B, cisplatin, foscarnet, or vancomycin should be closely monitored and avoided, if possible.