Pentamidine for Injection (Benambax) is an antimicrobial agent specifically indicated for the treatment of Pneumocystis carinii pneumonia (PCP). This drug is classified as a potent drug and must be used in strict compliance with prescription guidelines.
What is Pentamidine for Injection (Benambax)?
Pharmacological Actions
Pentamidine isethionate can inhibit glucose metabolism and protein synthesis of Pneumocystis in in vitro experiments.
It inhibits DNA synthesis, RNA synthesis, protein synthesis, phospholipid synthesis, and nucleotide synthesis of experimental tumors, and also suppresses the activity of dihydrofolate dehydrogenase (DHFR).
Clinical Application Scope
It is mainly indicated for patients with confirmed or highly suspected Pneumocystis carinii pneumonia.
Due to the risk of severe side effects, it must be used only after a thorough assessment confirming that the therapeutic benefits outweigh the risks.
Specifications and Properties of Pentamidine for Injection (Benambax)
Active Ingredient Composition
Each vial contains 300 mg of pentamidine isethionate.
Chemical name: 4,4'-(Pentanedioxy)dibenzamidine bis(2-hydroxyethanesulfonate).
Molecular formula: C₁₉H₂₄N₄O₂・2C₂H₆O₄S.
Molecular weight: 592.68.
Physical Properties of the Preparation
Appearance: White 块状 or powdered preparation (injection).
Solubility: Freely soluble in water, moderately soluble in methanol, slightly soluble in ethanol (95%), and almost insoluble in acetone or ether.
pH range: 4.5-6.5 after dissolution in 6 mL of water for injection.
Osmotic pressure ratio: 0.5-0.7 times that of normal saline after dissolution in 6 mL of water for injection.
Melting point: 188-192℃.
Other properties: Odorless and hygroscopic.
Storage Conditions of Pentamidine for Injection (Benambax)
Routine Storage Requirements
Storage condition: Room temperature.
Shelf life: 5 years.
Packaging specification: 5 vials per pack.
Preparation Precautions
For dissolution, only Japanese Pharmacopoeia water for injection must be used; normal saline or glucose solution shall not be used directly for dissolution.
Any unused residual portion after dissolution shall be discarded immediately.
The solution for intravenous or intramuscular injection can be further diluted with normal saline or glucose injection, but shall not be mixed with other injections.
Special Operation Specifications
When administering by inhalation, the operation must be conducted in a well-ventilated area, and operators shall wear protective equipment such as gloves and masks.
All preparations shall be protected from light and moisture.
