pentamidine isetionate: clinical use

Prescribing considerations

• Select the route according to the indication and use supervised administration.
• Administer parenteral treatment with the patient reclining and monitor for sudden hypotension.
• Assess cardiac disease, bradycardia, QT prolongation, electrolyte disturbance and concurrent QT-prolonging medicines.
• Use particular caution with renal or hepatic impairment, abnormal glucose, blood-pressure disorders, cytopenias, asthma or smoking history.
• Nebulised administration requires an appropriate device, environmental controls and protection against occupational or bystander exposure.

Contraindications and cautions

• Hypersensitivity to pentamidine isetionate.

Monitoring

• Blood pressure during and after parenteral administration.
• Renal function, urinalysis, full blood count, blood glucose, liver function and serum electrolytes including calcium and magnesium.
• ECG and QTc where clinically indicated, especially with cardiac disease or QT-prolonging medicines.
• Observe for bronchospasm and other severe reactions during inhaled treatment.
• Continue appropriate glucose surveillance after systemic treatment because delayed hyperglycaemia or diabetes has been reported.

Clinical pharmacology

Pentamidine is an aromatic diamidine that interacts with DNA, interferes with folate metabolism and inhibits RNA and protein synthesis. Nebulised administration produces high pulmonary exposure with substantially lower plasma concentrations than parenteral administration, although systemic toxicity remains possible.

Formulation and product differences

• The selected product is a single-use, excipient-free powder that must be reconstituted before administration.
• After preparation it may be used for intramuscular injection, intravenous infusion or inhalation, according to the indication.
• Only a clear solution practically free from particles should be used.
• Inhalation requires a suitable nebuliser; a nasal mask is not appropriate.
• Preparation for nebulisation should use appropriate containment, ventilation and exhaust filtration.

Injection

Route: Parenteral

Strengths: 300 mg