Company: MSD Ireland Human Health.
Legal category: Prescription. HT. Sport permitted.
Active ingredient: Posaconazole 100mg.
Description: Yellow, capsule-shaped gastro-resistant tablet marked 100 on one side.
Presentation: 24, €730.08.
Indications: Treatment of invasive aspergillosis, fusariosis, chromoblastomycosis, mycetoma, coccidioidomycosis, in adults with disease that is refractory to amphotericin B, itraconazole or fluconazole or in patients who are intolerant of these drugs. Prophylaxis of invasive fungal infections in: 1) Patients receiving remission-induction chemotherapy for acute myelogenous leukemia (AML) or myelodysplastic syndromes (MDS) expected to result in prolonged neutropenia and at high risk of developing invasive fungal infections; 2) Hematopoietic stem cell transplant (HSCT) recipients who are undergoing high-dose immunosuppressive therapy for graft versus host disease and at high risk of developing invasive fungal infections.
Pharmacology: Posaconazole is an antimycotic for systemic use. It is a triazole derivative. It inhibits the enzyme lanosterol 14α-demethylase (CYP51), which catalyses an essential step in ergosterol biosynthesis.
Dosage: Adult: 300mg loading dose twice on the first day, then 300mg once daily thereafter. Swallow whole. Treatment: Duration, based on the severity of the underlying disease, recovery from immunosuppression, and clinical response. Prophylaxis: Duration, based on recovery from neutropenia or immunosuppression. AML or MDS, start several days before the anticipated onset of neutropenia and continue for 7 days after the neutrophil count rises above 500 cells per mm3. Do not use tablet and oral suspension interchangeably. Children: Under 18 years, safety and efficacy not established.
Contraindications: Hypersensitivity to the active ingredient or to any of the excipients. Pregnancy (unless benefit outweighs risk), lactation. Women must use contraception during therapy.
Special precautions: Caution: Hypersensitivity to other azoles; hepatic impairment (evaluate liver function at the start of and during therapy (monitor patients who develop abnormal tests; consider discontinuation if liver disease suspected); pro-arrhythmic conditions (such as congenital or acquired QTc prolongation, cardiomyopathy (especially in the presence of cardiac failure), sinus bradycardia, existing symptomatic arrhythmias). Monitor and correct electrolyte disturbances (especially potassium, magnesium, calcium) before and during therapy. Severe diarrhoea or vomiting (monitor closely for breakthrough fungal infections). Posaconazole plasma concentrations higher with tablets than oral suspension (safety data limited). Driving/using machines.
Drug interactions: Contraindicated: Ergot alkaloids, CYP3A4 substrates that prolong the QTc interval (terfenadine, astemizole, cisapride, pimozide, halofantrine, quinidine), HMG-CoA reductase inhibitors metabolised through CYP3A4 (simvastatin, lovastatin, atorvastatin). Not recommended: Sirolimus. Avoid: Rifamycin antibacterials (rifampicin, rifabutin), certain anticonvulsants (phenytoin, carbamazepine, phenobarbital, primidone), efavirenz, vinca alkaloids. Caution: Other drugs prolonging the QTc interval, ciclosporin, tacrolimus, other CYP3A4 substrates (including HIV protease inhibitors, midazolam, triazolam, alprazolam, calcium channel blockers). UDP glucuronidation or p-glycoprotein (P-gp) efflux inhibitors (e.g. verapamil, clarithromycin, erythromycin) or inducers. Sulfonylureas (e.g. glipizide), fosamprenavir, digoxin.
Adverse drug reactions: Neutropenia, electrolyte imbalance, anorexia, hypokalaemia, paresthesia, dizziness, somnolence, headache, gastrointestinal disorders, elevated liver function tests, rash, pruritis, pyrexia, fatigue.
Full prescribing information and references available from MSD Ireland Human Health. Telephone: 01-2998700. E-mail: info@msd.ie.