In Brief
| Naproxen | |
|---|---|
| NNT at 500/550 mg | 2.7 (95% CI 2.3–3.2) |
| Age of the review | 2009 — older than the others in the series |
| Main distinction | Duration of action, not strength |
| Germany | OTC up to 250 mg/tablet, 750 mg/day, 7,500 mg/pack — under four conditions |
| Italy | OTC at 220 mg sodium; prescription from 500 mg |
| France | All prescription-only |
Naproxen occupies a place in the non-opioid list that is easy to undervalue. On strength it is mid-table: an NNT of 2.7 against the leader's 1.8. But it has a property none of its neighbours has, and the strength metric simply does not notice it.
What the Data Showed
The Cochrane review gives an NNT of 2.7 for the 500 or 550 mg dose, with a confidence interval of 2.3–3.2. As with the others in the series, this is the proportion of patients whose postoperative pain fell by at least half within six hours of a single dose.
One caveat about quality. The naproxen review appeared in 2009 — earlier than the other work in this series, and before certainty-of-evidence grading became mandatory. The accessible text has no certainty rating and no summary-of-findings table. That does not make the result wrong, but it is reported under older rules, and that is worth factoring in.
Where the difference really is established. Naproxen's interval (2.3–3.2) does not overlap etoricoxib's (1.7–2.0) — one of only two pairs in the whole five where the difference is supported by the numbers. With metamizole and ketoprofen the intervals overlap, and the order between them is not established at all.
Its Real Advantage
Naproxen's half-life is considerably longer than that of most NSAIDs. The practical consequence: it is taken twice a day rather than three or four times.
For pain that lasts days, that changes a good deal:
- fewer doses and fewer chances of missing one;
- steadier relief, without troughs towards the end of an interval;
- easier nights — one dose covers most of the sleep.
The NNT is measured six hours after a single dose. By construction that metric cannot capture duration of action — which is why naproxen always looks more modest in tables than it does in real use against protracted pain.
Where It Is Sold
Germany. The rules here run the opposite way from how they are usually stated, and it is worth getting right. Naproxen is prescription-only by default, and specific doses are carved out of that: up to 250 mg per divided form, 750 mg a day and 7,500 mg per pack. All three limits are inclusive.
But the exemption applies only when four conditions hold at once:
- solid oral forms only;
- no other active ingredients in the product;
- adults and children from 12 years;
- the indication «mild to moderate pain and fever».
Anything outside that frame — a higher dose, a combination product, another indication — remains prescription-only.
Italy. Naproxen sodium 220 mg is sold over the counter (tablets, soft capsules, granulate) — in the register that is Momendol. The 250 mg granulate sits in the class of «no prescription but no consumer advertising». All 500 mg, 550 mg sodium and 750 mg modified-release forms are strictly prescription — and that includes Synflex, which is often assumed to be over the counter. The difference between the two names is practical: the same substance, but one you can simply buy and the other needs a prescription.
France. All naproxen is prescription-only, including the 220 mg strength.
Safety
- Stomach. A non-selective NSAID with the usual risk of erosions and bleeding; with a history of peptic ulcer, only on a doctor's decision.
- Kidneys and blood pressure. It reduces renal blood flow and can raise blood pressure.
- Duration cuts both ways. The same property that makes dosing convenient also means longer exposure for the stomach lining and the kidneys.
- Never two NSAIDs at once.
- OTC packs are sized for short courses. If pain lasts beyond a few days, that is a reason to see a doctor rather than to buy the next box.
The Bottom Line
Naproxen is not about peak strength but about staying power. It looks average in the table because strength is measured over six hours, while its virtue shows up on the second and third day.
Hence its practical place: it makes sense where pain is expected to drag on, rather than where a peak needs flattening within the hour.
About buying
The drug is in the catalogue: Synflex (naproxen sodium) 550 mg. No price is shown — prescription medicines are ordered through the chat, and the administrator confirms availability and cost. The prescribing stays with a doctor: this guide explains what is known about the drug, it does not replace a consultation.
