Clinical beta

FMBM is currently in clinical beta. Content is for professional review/testing and must not replace local protocols, senior clinical judgment, or official prescribing references.

Drug Monograph

Loxoprofen

USE IF: Mild-moderate pain, musculoskeletal pain, dental pain, OA/RA, URTI fever

AVOID IF: GI ulcer/bleed, CKD, AERD/asthma, pregnancy >=30 weeks

Loxoprofen

Non-selective NSAID (propionic acid derivative; prodrug)

NSAIDOTC (KSA)RoxoninProdrugMusculoskeletal pain

Indication

Mild-moderate pain, musculoskeletal pain, dental pain, OA/RA, URTI fever

At a glance

INDICATION -> Mild-moderate pain (OTC NSAID in Saudi Arabia)

ADULT DOSE -> 60 mg TID (chronic) OR 60-120 mg PRN

MAX DOSE -> 180 mg/day

CONTRA -> GI bleed/ulcer, CKD, AERD/asthma, pregnancy >=30 weeks

ANTIDOTE -> None

Quick facts

Onset

30-60 min (oral), 2-4 h (patch)

Duration

Peak 30-50 min; duration 4-8 h; half-life ~75 min (can increase in overdose).

Routes

PO (systemic); transdermal patch (local effect, NOT systemic equivalent)

Pregnancy

Avoid >=20 weeks; contraindicated >=30 weeks

Renal

Avoid severe impairment

Hepatic

Reduce dose

Do not miss

Time to action: analgesia ~30-60 min (anti-inflammatory effect may take longer)

Max dose

  • 180 mg/day (strict ceiling).

Critical risks

  • GI bleed.
  • AKI.
  • Anaphylaxis.
  • SJS/TEN.

Antidote

  • No specific antidote.

High-risk scenarios

  • Quinolone + loxoprofen -> seizure risk.
  • Triple whammy: NSAID + ACEi/ARB + diuretic -> high risk of AKI.

Key interactions

  • Warfarin.
  • Methotrexate.
  • Lithium.
  • ACEi/ARB + diuretics.

Indications

Primary

  • Osteoarthritis
  • Rheumatoid arthritis
  • MSK pain
  • Dental/post-extraction pain

Secondary

  • Fever (URTI)
  • Dysmenorrhea
  • Postoperative pain

Other

  • Gout (off-label)
  • Headache/migraine (off-label)

Dosing

Standard: 60 mg TID

Max daily dose

  • Standard 60 mg TID.
  • Maximum 180 mg/day.

Adult - PO

  • Chronic: 60 mg TID.
  • PRN: 60-120 mg once.

Patch

  • No IV formulation.

Pediatric

  • Not recommended (<18 years).

Renal adjustment

  • Mild impairment: reduce dose.
  • Severe impairment: contraindicated.

Hepatic adjustment

  • Reduce dose.
  • Severe hepatic disease: contraindicated.

Warnings

Clinical warnings

  • GI bleeding/ulcer/perforation can be fatal.
  • AKI, nephrotic syndrome, hyperkalemia.
  • Anaphylaxis/angioedema.
  • SJS/TEN (rare, life-threatening).
  • AERD can trigger bronchospasm.
  • Hepatotoxicity including fulminant hepatitis reported.
  • Can mask infection signs by suppressing fever.
  • Reversible platelet inhibition (less than aspirin but still increases bleeding risk).

Adverse effects

  • Common: dyspepsia, nausea, dizziness, edema.
  • Serious: GI bleed, AKI, severe skin reaction, anaphylaxis.

Contraindications / caution

Do not use

  • Active GI ulcer/bleed.
  • Severe renal failure.
  • Severe hepatic failure.
  • Severe heart failure.
  • AERD / aspirin asthma.
  • Pregnancy >=30 weeks.

Use caution / avoid high doses

  • Elderly.
  • Hypertension / CVD.
  • Mild CKD.
  • Concomitant anticoagulants.
  • Dehydration.

Drug interactions

  • Quinolones -> seizures (GABA inhibition).
  • Warfarin -> increased bleeding (monitor INR).
  • Methotrexate -> increased toxicity.
  • Lithium -> increased levels.
  • Sulfonylureas -> hypoglycemia risk.
  • ACEi/ARB + diuretics -> AKI (triple whammy).
  • Steroids/SSRIs -> increased GI bleeding risk.

Special populations

Pediatrics

Not recommended under 18 years.

Pregnancy

Avoid >=20 weeks; contraindicated >=30 weeks.

Breastfeeding

Avoid (limited data).

Elderly

Start lower (e.g., 60 mg OD-BD) and monitor closely.

Liver disease

Reduce dose; avoid severe disease.

Renal impairment

Avoid in moderate-severe CKD (risk of further renal decline and AKI).

Administration

  • Take oral doses with food (critical).
  • Avoid empty stomach dosing.
  • Patch once daily; do not apply to broken skin.
  • Remove from blister before ingestion.
  • No IV formulation.

Monitoring

  • Renal function baseline and at 1-2 weeks.
  • LFTs baseline and periodic.
  • GI bleeding symptoms.
  • Blood pressure.
  • INR if on warfarin.
  • Glucose if on sulfonylureas.
  • Lithium levels when co-prescribed.

Overdose / toxicity

STOP drug immediately -> assess ABCs and treat as NSAID toxicity.

Recognition

  • Toxic dose may be >10x therapeutic (~>1.8 g).
  • Nausea, GI bleed, AKI, CNS depression.

Immediate actions

  • Activated charcoal if early.
  • IV fluids.
  • PPI therapy.
  • Monitor renal function.

Antidote

  • No antidote.

Decontamination

  • Activated charcoal early when appropriate.

Escalation

  • ICU if severe AKI, GI bleed, or altered mental status.

Clinical pearls

Common mistakes, resistance logic, and bedside traps

OTC context

  • OTC status in Saudi means medication history must be actively queried.

Quinolone risk

  • Quinolone + loxoprofen can increase seizure risk.

Prodrug reality

  • Prodrug converted to active metabolite -> slightly improved GI tolerability (not protective).

No IV option

  • No IV form; use ketorolac when IV NSAID is needed.

Patch utility

  • Patch can be useful in elderly/localized pain settings.

Food rule

  • Always prescribe/administer with food.

Duplication check

  • Check for hidden NSAID duplication across OTC products.

Pharmacokinetics

  • Rapid oral absorption (~95% bioavailability).
  • Highly protein bound (~97%).
  • Hepatic activation via carbonyl reductase.
  • Renal excretion as metabolites.
  • No major accumulation at therapeutic dosing.

Mechanism of action

  • Prodrug converted to active trans-OH metabolite.
  • Inhibits COX-1 and COX-2.
  • Reduced prostaglandins -> analgesic, antipyretic, anti-inflammatory effect.

Common brand names

Saudi Arabia

Roxonin · Roxonin Tape

Global

Loxonin · Loxonin S · Loxomac · Japrolox · Generic loxoprofen

Common trade names are curated examples only — formulations and availability vary. Verify the exact product name with your local pharmacy and national regulator before prescribing or dispensing.

Country practice notes

  • Widely used OTC in Saudi Arabia (Roxonin; SAJA Pharma).
  • Frequently self-medicated for dental, ENT, and musculoskeletal pain.
  • Often co-prescribed with antibiotics; quinolone interaction risk is clinically important.
  • Available as oral tablets and transdermal patch (Roxonin Tape).
  • Not on MOH essential list but widely used in community settings.

Saudi Arabia — confirm with local formulary.