In Reply: If costs were equal between first- and second-generation antiviral agents for influenza, I suspect that oseltamivir and zanamivir would quickly replace amantadine and rimantadine. The broad spectrum of second-generation antiviral agents and somewhat better adverse effects profile would be the rationale for their preference by clinicians.
The greater expense of the newer antiviral agents, often not reimbursed, has led some hospitals to stock only amantadine or rimantadine in their formulary. In the face of a known outbreak of influenza A, this is reasonable, especially since older patients with decreased creatinine clearance could be monitored closely as inpatients. A dilemma arises, however, when both influenza A and B are circulating at the same time: Should the more expensive second-generation antivirals be used routinely or should patients have rapid viral diagnostic testing of sputum or oral washings to confirm infection with specific influenza types? Currently, some hospitals charge $50 to $100 for rapid viral tests, an amount equal to or greater than the cost of the neuraminidase inhibitors.
Wenzel RP. Antiviral Agents for Influenza—Reply. JAMA. 2000;283(23):3070. doi:10.1001/jama.283.23.3068d