How effective is mometasone furoate for sinusitis?

For acute sinusitis, mometasone furoate nasal spray works better than amoxicillin or placebo at relieving symptoms, but the evidence comes from a single manufacturer-funded trial from 2005.

The main study [1] was a large, randomized, double-blind trial across 71 centers, funded by Schering-Plough (the drug's maker). It compared mometasone spray (200 mcg twice daily) to amoxicillin and placebo in 981 adults with acute uncomplicated sinusitis. The spray beat both placebo and amoxicillin on symptom scores over 15 days, with similar rates of side effects (about 36% had an adverse event in the spray group, 38% in the placebo group) [1]. Recurrence during follow-up was lowest in the twice-daily spray group at 4.3%, versus 7.1% for placebo [1].

The evidence has limits. This is one trial, funded by the manufacturer, and it tested only acute sinusitis in adults over 15 days. There is no long-term safety data from this trial, no data on chronic sinusitis from this specific study, and no comparison to a true untreated group (everyone got some spray or capsule). A separate 2022 trial [3] tested a nano-formulation in only 20 people, too small to draw conclusions. The 2018 trial [2] on mometasone sinus implants is for a different condition (chronic sinusitis with nasal polyps after surgery) and does not apply to simple sinusitis.

My call: mometasone furoate spray is a reasonable option for short-term symptom relief in acute sinusitis, based on one manufacturer-funded trial. It is not a cure and does not replace antibiotics if a bacterial infection is confirmed. Confidence: moderate for acute sinusitis symptom relief; low for any other sinusitis type or long-term use.