Pentamidine
PENTAM
What it isMacromolecular-biosynthesis inhibitor used IV for Pneumocystis treatment or inhaled for prophylaxis when preferred drugs fail.
Why this oneInhalation offers non-sulfonamide prophylaxis with less systemic exposure, while IV treatment reaches established disease.
What limits itParenteral use can cause fatal hypotension, dysglycemia, pancreatitis, renal injury, and arrhythmia; inhaled drug misses extrapulmonary sites.
FDA-approved for
- PCP pneumonia (~1984)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Prevention of Pneumocystis jiroveci pneumonia | adult | 300 mg once every 4 weeks (nebulized) |
Renal Undefined
Hepatic Undefined
Single 300 mg dose repeated every 4 weeks.
Instructions
- Reconstitute 300 mg in 6 mL Sterile Water for Injection ONLY (saline causes precipitation)
- Administer via Respirgard II nebulizer until chamber is empty (~30-45 min), flow 5-7 L/min
- Do not mix with any other drug; use freshly prepared solution
Contraindications
- History of anaphylactic reaction to inhaled or parenteral pentamidine isethionate
Cautions
- Bronchospasm/cough (may require bronchodilator pretreatment)
- Pancreatitis, SIADH reported
- Hypoglycemia and hyperglycemia
- QT prolongation / torsade de pointes
Adverse reactions
- Cough, wheezing, shortness of breath, chest pain
- Decreased appetite, fatigue, dizziness
- Fever, night sweats
- Bad taste
- Nausea, diarrhea
- Rash
Pregnancy Pregnancy Category C - no adequate human studies; use only if clearly needed.
Lactation Undefined
⚠ BOXED WARNING
- Fatal severe hypotension, hypoglycemia, acute pancreatitis, and cardiac arrhythmias have occurred; reserve parenteral pentamidine for Pneumocystis pneumonia when safer therapy is unsuitable
Cost, est. cash$20–$1,500/dose or month
Generic entry1992
Classes and tags
Clinical profile
Legacy pregnancy categoryUnknown / historical label unavailable
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.
Mechanism of action: Pentamidine ballicule
