Nitrofurantoin Formulation Cost Comparison
Nitrofurantoin macrocrystal formulation is generally less expensive than the monohydrate macrocrystal formulation.
Formulation Differences and Cost Implications
Nitrofurantoin is available in two main formulations:
Nitrofurantoin macrocrystal (Macrodantin®)
- Original formulation
- Generally less expensive
- Has been available since the 1950s 1
Nitrofurantoin monohydrate/macrocrystal (Macrobid®)
- Newer dual-release formulation
- Typically more expensive
- Combines immediate and extended-release properties
Clinical Context
While cost is an important consideration, it's worth noting some clinical differences between the formulations:
- Both formulations are effective first-line treatments for uncomplicated UTIs 2
- Standard dosing for uncomplicated UTIs is typically 100 mg twice daily for 5 days 2
- The macrocrystal formulation has been successfully used at lower doses (50 mg daily) for prophylaxis with good efficacy and tolerability 3
Tolerability Considerations
When considering cost-effectiveness, tolerability affects overall value:
- The macrocrystal formulation (Macrodantin) at 50 mg has shown a favorable safety and tolerability profile in long-term prophylaxis 3
- Higher doses of the microcrystalline formulation (50 mg twice daily) have been associated with more nausea compared to macrocrystalline formulations 3
Prescribing Considerations
When prescribing nitrofurantoin based on cost considerations:
- Both formulations remain effective against most uropathogens with relatively low resistance rates (20.2% at 3 months) compared to other antibiotics 2
- Avoid nitrofurantoin in patients with:
- Renal impairment (GFR <30 ml/min)
- Third trimester of pregnancy
- Infants less than 4 months of age 2
Bottom Line
If cost is the primary concern and the patient can tolerate either formulation, the macrocrystal formulation offers the more economical choice while maintaining clinical efficacy for both treatment and prophylaxis of UTIs.